Download Anatomy of the Abdomen and pelvis

Anatomy of the Abdomen and pelvis
03 May 2012
08:48
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hope you find them useful, please feel free to email me if you have any
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For the Anatomy of The Abdomen and Pelvis notes I used a mixture of
Gray's, Netter's and Clinically Orientated Anatomy. In addition some detail
is taken from Instant Anatomy for android written by Dr. Robert Whitaker
who teaches anatomy at Cambridge.
I organise my notes so that you should read the learning objectives on the
left then proceed down the right hand side for a few learning objectives
and then cross back over to the left and continue like that.
Anything in this highlighted green is a definition or explains basically
something's function.
Text highlighted in yellow or with a star is what I would deem important
and key to your learning.
Italics and bold just help to make certain terms stand out.
The notes are a bit quirky but I hope you like them and find some of the
memory aides strange enough so that they stick in your head.
I provide them to you in OneNote format as that is how I created them,
they can be saved as PDF but the formatting is not as nice. The one caveat
with this is that these notes are freely copy able and editable. I would
prefer if you didn't copy and paste my notes into your own but used them
as a reference or preferably instead embellished these already existing
notes by adding to them.
Good luck with first year
Stuart Taylor
Stuart's Anatomy of the Abdomen and Pelvis Page 1
Abdominal wall, inguinal region and hernias
03 May 2012
08:58
Describe the rectus sheath and its contents.
Define the linea alba and the linea semilunaris
Demonstrate in the living subject and in dissected material the nature and
course of the inguinal canal making correct use of the following terms:
superficial and deep inguinal rings, mid-inguinal point, pubic tubercle, testis,
testicular vessels, scrotum, spermatic cord, ductus deferens, round ligament
of the uterus.
Distinguish between direct and indirect inguinal hernias.
Distinguish between acquired and congenital inguinal hernia
Summarise the anatomical basis for femoral hernia.
Explain the importance of the distinction between the fatty and
membranous layers of the superficial fascia
Describe the rectus sheath and its contents.
3 levels
• Above costal margin
• Between costal margin and arcuate line
• Below arcuate line
• Arises from costal cartilages 5-7 and the xiphoid process and descends lateral to the
linear alba to insert on the pubic crest and the front of the pubic symphysis.
• Divided into segments by transverse tendinous intersections
General information on hernias
• Hernia- A protrusion of a viscus through a defect in its containing compartment such
that it lies in an abnormal position.
• Reducible- sac returns to containing cavity
• Irreducible- sac cannot be returned to containing cavity
• Obstructed- sac contains blocked bowel
• Strangulated- sac 's contents with strangulated blood supply
• Children can be born with a defect in the groin.
• 10x more common in males because of embryological descent of testes.
Distinguish between direct and indirect inguinal hernias.
Indirect
• This is the most common type
• Tend to be in younger adults and children
• Due to lax deep ring or patent processus vaginalis.
• More common on the right hand side.
• The deep ring is too large, peritoneum pushes through.
• Indirect hernia defect is always the deep/internal ring which is always LATERAL to
the inferior epigastric vessels.
Direct
• Groin hernias that occur in old people.
• Acquired defect in posterior wall of the inguinal canal.
• Associated with chronic straining.
• A direct hernia defect tends to go through Hesselbach's triangle, which is always
MEDIAL to the inferior epigastric vessels.
Medial
Lateral
• Rectus abdominis lies deep to the aponeurosis of the external oblique throughout its
length.
• In the upper two-thirds of the anterior abdominal wall it lies anterior to the transversus
abdominis aponeurosis while the internal oblique aponeurosis splits to enclose it.
• Rectus abdominis therefore lies in a fibrous tunnel called the rectus sheath. The
anterior wall of the sheath consists of the aponeurosis of external oblique fused with
the anterior leaf of the internal oblique aponeurosis. Similarly the posterior wall
comprises the posterior leaf fused with the transversus abdominis aponeurosis.
• In the lower part of the sheath, all the aponeuroses pass anterior to rectus so that this
part is ‘backless’.
• The free lower posterior margin of the posterior layer of the rectus sheath is known as
the arcuate line.
Define the linea alba and the linea semilunaris
• At the lateral margin of the rectus abdominis the aponeuroses of the three flat muscles
fuse to form the linea semilunaris before enclosing the rectus muscle and fusing again
in the midline at the linea alba.
Contents:
Inferior epigastric
Vessels
Hesselbach’s Triangle
• Arteries and veins lying posterior to the muscle. These are the epigastric vessels.
• There is an anastomosis between the superior epigastric artery, which is a branch of the
internal thoracic, and the inferior epigastric, which forms an interesting though
relatively useless bypass of the abdominal and descending aortas.
• Nerve supply to the muscles are from T6-L1
• Intercostal nerves are from T6-T12 and the main trunks of these lie between the
Internal oblique and Transversus abdominis layers (like the intercostal nerves in the
chest wall)
Arrangement of the sheet muscles
Distinguish between acquired and congenital inguinal hernia
• Most often occurs in male babies due to a patent processus vaginalis.
• Processus is required for testicular descent and if it does not close properly the baby can
get an indirect hernia.
• Testes start out at the level of the kidneys which migrate to the scrotum.
• They descend at the back of the abdomen.
• There is a finger of peritoneum and the testes descend behind it which acts as a guide.
• The finger of peritoneum is supposed to seal off which can be filled with bowel.
Patent Processus
Vaginalis
The three sheet muscles, from superficial to deep, are:
Stuart's Anatomy of the Abdomen and Pelvis Page 2
Patent Processus
Vaginalis
The three sheet muscles, from superficial to deep, are:
 External oblique
• Slips off of ribs 5-12 and descends antero-inferiorly. Has an important free posterior
border which runs from the anterior superior iliac spine (ASIS) to the pubic tubercle
forming the inguinal ligament.
NORMAL
PATENT PROCESSUS
 Internal oblique
• Originates from lumbar fascia, anterior 2/3 of iliac crest and lateral 2/3 of the inguinal
ligament.
•
•
•
•
•
•
•
Factors associated with hernia
Chronic cough-COPD, asthma
Prostatic disease
Constipation
Muscular effort e.g. job
Previous hernia repair
Obesity
Ascites
• Highest ascend to ribs 10-12 lowest descend to the crest and medial part of pectineal line
of the pubis.
 Transversus abdominis
• Runs medially from the inner aspect of the costal margin from ribs 7-12, the lumbar
fascia and from the anterior 2/3 of the iliac crest to the lateral 1/3 of the inguinal
ligament.
• Lowest fibres insert on the pubic crest and the pectineal line with the lower part of the
internal oblique muscle as the conjoint tendon.
Treatment is to stich or clip in a mesh of polyproponene low chance of recurrence is 1%.
Distinguish between acquired and congenital inguinal hernia
Summarise the anatomical basis for femoral hernia.
• Femoral hernia protrudes through the femoral canal.
• Very tight hole which is dangerous because it causes bowel to lose its blood supply.
• Below and lateral to pubic tubercle is femoral above and medial is inguinal.
Borders of the femoral canal
Superior- Inguinal ligament
Inferior- Pectineus fascia
Medial- Lacunar ligament
Lateral- Femoral vein
The arrangement is homologous with the three layers of muscles found in the intercostal
spaces. All three originate from the margins of the anterolateral wall, turn into aponeuroses
(sheet-like tendons) in the anterior abdominal wall, and insert into a tough fibrous band called
the linea alba (white line) that extends in the mid-line from the xiphoid process of the
sternum to the pubic symphysis.
Demonstrate in the living subject and in dissected material the nature and
course of the inguinal canal making correct use of the following terms:
superficial and deep inguinal rings, mid-inguinal point, pubic tubercle, testis,
testicular vessels, scrotum, spermatic cord, ductus deferens, round ligament of
the uterus.
Inguinal canal
• A canal formed by the layers of the abdominal wall muscle.
• Approximately 4cm long.
• It runs from the deep ring to the superficial ring.
• Transmits the spermatic cord in the male and round ligament of the uterus in females.
Also transmits into ilioinguinal nerve.
ANTERIOR SUPERIOR ILIAC
SPINE
DEEP RING
INGUINAL CANAL
PUBIC
TUBERCLE
History
• Lump in the groin
• May come and go
• There all the time
• Painful
• Vomiting/ constipation
• Associated conditions.
Deep ring- The deep (internal) ring is an opening in the back wall of the inguinal canal
through which the canal's contents enter.
Superficial ring- V shaped slit in the external oblique aponeurosis that allows the content of
the canal to exit e.g. to the scrotum.
Summary of the borders of the inguinal canal
Anterior- External oblique aponeurosis + internal oblique
Floor- Inguinal ligament
Roof- Internal oblique arching over
Posterior- Transversalis fascia and conjoint tendon medially
(Transversalis is the same thing as transversus abdominis)
• On examination femoral hernias tend to be irreducible, and hot and painful if
strangulated.
Stuart's Anatomy of the Abdomen and Pelvis Page 3
• On examination femoral hernias tend to be irreducible, and hot and painful if
strangulated.
• They can be distinguished from inguinal hernias because they appear below and lateral
to the pubic tubercle.
• Inguinal hernias are above and medial to the pubic tubercle.
ANTERIOR
SUPERIOR
ILIAC SPINE
PUBIC
TUBERCLE
FEMORAL HERNIA
BELOW AND LATERAL
TO PUBIC TUBERCLE
Explain the importance of the distinction between the fatty and membranous
layers of the superficial fascia
• The superficial facia of the abdominal wall (subcutaneous tissue of the abdomen) is a
layer of fatty connective tissue. It is usually a single layer similar to, and continuous with
the superficial fascia throughout other regions of the body. However in the lower region
of the anterior part of the abdominal wall, below the umbilicus, it forms two layers: a
superficial fatty layer and a deeper membranous layer.
Superficial fatty layer
• This layer contains fat and varies in thickness. It is also known as Camper's fascia.
• It is continuous over the inguinal ligament with the superficial fascia of the thigh and
with a similar layer in the perineum.
• In men, this superficial layer continues over the penis and, after losing its fat and fusing
with the deeper layer of superficial fascia, continues into the scrotum where it forms a
specialised fascial layer containing smooth muscle fibres (the dartos fascia). In women,
this superficial layer retains some fat and is a component of the labia mayor.
Deeper Layer
• The deeper membranous layer of superficial fascia (Scarpa's fascia) is thin and
membranous, and contains little or no fat. Inferiorly, it continues into the thigh, but just
below the inguinal ligament, it fuses with the deep fascia of the thigh.
• In the mid-line, it is firmly attached to the linea alba and the symphysis pubis. It
continues into the anterior part of the perineum where it is firmly attached to the
isciopubic rami and to the posterior margin of the perineal membrane. Here, it is
referred to as the superficial perineal fascia (Colles' fascia)
• In men, the deeper membranous layer of superficial fascia blends with the superficial
layer as they both pass over the penis, forming the superficial fascia of the penis, before
they continue into the scrotum where they form the dartos fascia.
• Also in men, extensions of the deeper membranous layer of superficial fascia attached to
the pubic symphysis pass inferiorly onto the dorsum and sides of the penis to form the
fundiform ligament of penis.
• In women, the membranous layer of the superficial fascia continues into the labia
majora and the anterior part of the perineum
Stuart's Anatomy of the Abdomen and Pelvis Page 4
Living Anatomy
31 May 2012
12:34
Iliac tubercle is 5cm behind the Anterior Superior Iliac Spine
Transpyloric plane is from the 9th costal cartilages across.
Subcostal plane is the horizontal plane at level of costal margin in the Mid axillary line
Transtubercular plane is the plane across the iliac tubercles.
Supracrestal plane- Transverse plane running along the top of the iliac crests just
below the umbilicus.
Structure
Vertebral
level
1
Xiphisternum
2
Transpyloric plane
T8/9
L1
3
Tip of 9th costal cartilage
L1
4
Subcostal plane (Rib 10)
5
Umbilicus
6
Supracristal plane
7
Iliac tubercles
L5
8
ASIS and PSIS/ Sacral Dimple
S2
9
Midpoint of sacroiliac joint
S2
L2
L3/4
L4
Structures at Transpyloric Plane:
• L1 vertebrae
• 9th CC
• Origin of SMA
• Formation of Portal Vein
• Neck of the Pancreas
• Hilum of the Kidney
• Hilum of the Spleen
• Duodenal-jejunal flexure
• Pylorus
• Transverse Colon
• Fundus of gall bladder
• End of spinal cord
That’s 12 bitches.
• Formed from the transtubercular plane, subcostal plane and two midclavicular
vertical planes.
Stuart's Anatomy of the Abdomen and Pelvis Page 5
Gut and Peritoneum
08 May 2012
09:00
Define parietal and visceral peritoneum and explain the functions of the
peritoneum and peritoneal cavity
Learning Objectives
Define parietal and visceral peritoneum and explain the functions of
the peritoneum and peritoneal cavity
Draw diagrams to explain different relationships to the peritoneum
(mesenteries and retroperitoneal positions) and list the structures
contained within a typical mesentery
Describe the peritoneal reflections in relation to major parts of the gut
and associated organs from the oesophagus to the rectum, with
special attention to the attachments and contents of the greater and
lesser omenta and the mesentery proper
• Normally elements of the gastrointestinal tract and its derivatives completely fill the
abdominal cavity, making the peritoneal cavity a potential space, and visceral
peritoneum on organs and parietal peritoneum in the adjacent abdominal wall slide
freely against one another.
• The peritoneum is a epithelial like single layer of cells (the mesothelium) together with
a supportive layer of connective tissue. Peritoneum is similar to the pleura and serous
pericardium in the thorax.
• The peritoneum reflects off the abdominal wall to become a component of the
mesenteries that suspend the viscera.
• Components of the GI tract are suspended in peritoneal reflections called
mesenteries.
Describe the boundaries of the lesser sac and of the epiploic foramen
(of Winslow)
Parietal Peritoneum
Name the regions of the gut from oesophagus to rectum and
summarise their main functions
Describe the sources and distribution of arteries to important
structures or organs derived from the foregut, midgut and hindgut.
Describe the peritoneal reflections in relation to major parts of the gut and
associated organs from the oesophagus to the rectum, with special attention to
the attachments and contents of the greater and lesser omenta and the
mesentery proper
Foregut- Distal 3rd of oesophagus to the 2nd part of the duodenum at the entrance of the bile
duct (Major duodenal papilla)
Midgut- 2nd part of the duodenum to two-thirds along transverse colon.
Hindgut- Distal 3rd of transverse colon to the rectum.
Visceral Peritoneum
Mesentery
Viscera
e.g. Bowel
Peritoneal Cavity
• Parietal peritoneum lines the abdominal wall
• Visceral peritoneum covers suspended organs.
•
•
•
•
GI tract is suspended from the posterior/dorsal aspect.
Peritoneal folds attaching viscera to the abdominal wall.
Filled with peritoneal fluid secreted by the mesothelium.
Epithelial layer secretes the fluid and circulates into the lymphatic vessels especially at
the inferior surface of the diaphragm.
Draw diagrams to explain different relationships to the peritoneum
(mesenteries and retroperitoneal positions) and list the structures contained
within a typical mesentery
Intra vs. Retroperitoneal
endoderm
+ 4 wk IUL
•
•
•
•
•
• Intraperitoneal- structures e.g. most of small intestine, suspended from the abdominal
wall by mesenteries.
• Retroperitoneal- structures e.g. kidneys and great vessels i.e. aorta and vena cava that
lie between parietal peritoneum and posterior abdominal wall.
Anterior/Ventral
Endoderm, ectoderm and mesoderm.
Yolk sac has no defined function
The gut originates from the endoderm and splanchnic mesoderm.
It is suspended from the posterior abdominal wall by a peritoneal fold- the dorsal mesentery.
Blood supply, lymphatics and nerve supply all run through the mesentery.
INTRAperitoneal
RETROperitoneal
Great Vessels
• The entire gut tube is suspended from a dorsal mesentery.
• In addition the foregut has a ventral mesentery.
Ventral
Kidneys
Dorsal mesentery
• The foregut has a ventral mesentery containing the liver, which splits into the falciform
ligament and the lesser omentum.
Formation of the Omental Bursa (Lesser sac)
• Secondary fusion of the duodenum to the body wall, massive growth of the liver in the ventral
mesentery, and fusion of the superior surface of the liver to the diaphragm restrict the
opening to the space enclosed by the ballooned dorsal mesentery associated with the
stomach. This restricted opening is the omental foramen (epiploic foramen)
Retroperitoneal structures:
Primary
Suprarenal glands (the adrenals)
Kidneys
Ureter
Bladder
Aorta
IVC
Esophagus
Rectum (part, lower 3rd is
extraperitoneal
Intraperitoneal organs
• Stomach
• 1st part of duodenum
• Jejunum
• Ileum
• Cecum
• Appendix
• Transverse Colon
• Sigmoid Colon
• Rectum (Upper 1/3)
• Liver
Secondary *
• Spleen
• The head, neck, and body of the pancreas
• Tail of pancreas
but not the tail which is located in
the splenorenal ligament.
In women- Uterus, Fallopian Tubes,
• Duodenum apart from the proximal
Ovaries
first segment which is intraperitoneal
•
•
•
•
•
•
•
•
• Ascending and descending portions of
colon (but not the transverse or cecum)
• Good memory aide is SAD PUCKER.
* These organs originally had a mesentery, then became secondarily retroperitoneal when
the mesentery fused with the body wall.
GI tract Basic Plan
Stuart's Anatomy of the Abdomen and Pelvis Page 6
opening to the space enclosed by the ballooned dorsal mesentery associated with the
stomach. This restricted opening is the omental foramen (epiploic foramen)
the mesentery fused with the body wall.
GI tract Basic Plan
Mesentery
Muscularis:
Mucosa:
Serosa:
• The part of the abdominal cavity enclosed by the expanded dorsal mesentery, and posterior to
the stomach, is the omental bursa (lesser sac). Access through the omental foramen to this
space from the rest of peritoneal cavity (greater sac) is inferior to the free edge of the ventral
mesentery.
• Part of the dorsal mesentery that initially forms part of the lesser sac greatly enlarges in an
inferior direction, and the two opposing surfaces of the mesentery fuse to form an apron like
structure (the greater omentum).
• The greater omentum is suspended from the greater curvature of the stomach, lines every
other viscera in the abdominal cavity, and is the first structure observed when the abdominal
cavity is opened anteriorly.
• THE TWO GREATERS GO TOGETHER- GREATER OMENTUM AND GREATER CURVATURE
• As the liver grows it moves to the right while the dorsal mesentery and spleen move to the
left. The original right side of the upper peritoneal cavity is now posterior- the lesser sac of the
peritoneal cavity.
submucosa
• Mucosa:
 Made up of epithelium
 Lamina propia
 Muscularis mucosae which is a layer of muscle needed to mobilise
mucous.
• Mesentery:
 Contains arteries and nerves that supply the tissue
• Serosa:
 Areolar connective tissue
 Serosa is a connective tissue layer with epithelium which also lines the
visceral peritoneum.
• Muscularis:
• Controlled by the autonomic nervous system. Contraction of two layers of
muscle (circular and longitudinal) are needed to initiate peristalsis.
Name the regions of the gut from oesophagus to rectum and summarise
their main functions
Oesophagus
• Oesophagus pierces diaphragm at T10.
• Pierces muscular part of diaphragm and contributes to Lower Oesophageal
Sphincter which helps prevent gastro-oesophageal reflux.
• Acts as a conduit for food and water which allows food to be digested in the
stomach.
Apparently this is a rage comic drawing of Nicholas Cage!!!
Note this knowledge is not examinable unfortunately.
Lower part of dorsal foregut mesentery extends down as a double fold called the greater
omentum anterior to the intestine.
The lesser omentum is part of the ventral foregut mesentery.
Stomach
• A ring of smooth muscle at distal end of Pyloric Canal prevents food entering
duodenum.
• Four main parts:
a. Cardia surrounding the opening
b. The fundus which is superior to cardia
c. The body
d. Pyloric region consisting of pyloric antrum and pyloric canal.
• Sphincter controls flow of food into duodenum.
Fundus
Pyloric
canal
• Functions of greater omentum:
i. Fat deposition, having varying amounts of adipose tissue
ii. Immune contribution, having milky spots of macrophage collections
iii. Infection and wound isolation; It may also physically limit the spread of
intraperitoneal infections. The greater omentum can often be found wrapped
around areas of infection and trauma.
Describe the boundaries of the lesser sac and of the epiploic foramen (of
Winslow)
Stuart's Anatomy of the Abdomen and Pelvis Page 7
Pyloric
antrum
Body
Duodenum
• First part is more horizontal and is known as the duodenal cap and is where most
duodenal ulcers occur.
• Second part of duodenum contains entrance for common bile duct - Major
Duodenal Papilla
• Most of the duodenum is retroperitoneal.
• 1-2 cm at beginning is intraperitoneal.
1
Describe the boundaries of the lesser sac and of the epiploic foramen (of
Winslow)
• Most of the duodenum is retroperitoneal.
• 1-2 cm at beginning is intraperitoneal.
1
2
4
3
lesser
omentum
• The portal vein, hepatic artery and bile duct run between the posterior abdominal wall
and liver within the lesser omentum near its free edge. This free edge is present because
the ventral mesentery ends at the start of the midgut.
1
2
lesser sac
4
3
Jejunum Vs Ileum
Jejunum
Ileum
Proximal 2/5
Distal 3/5
Larger in diameter
Smaller in diameter
Upper left quadrant of abdomen Lower right quadrant of abdomen
greater sac
Less prominent arterial arcades Prominent arterial arcades
Longer vasa recta
Shorter vasa recta.
Large Intestine:
Haustra pocketed walls)
Epiploic
foramen
right
The greater and lesser sacs of the peritoneal cavity
communicate through a narrow opening called the epiploic
foramen (entry to the lesser sac). This lies just below the
liver, posterior to the free edge of the lesser omentum.
• The lesser omentum (small omentum; gastrohepatic omentum; omentum minus) is the
double layer of peritoneum that extends from the liver to the lesser curvature of the
stomach and the start of the duodenum.
• Lesser sac (Omental Bursa)- Is the cavity in the abdomen that is formed by the lesser and
greater omentum. Usually found in mammals, it is connected with the greater sac via the
epiploic foramen (also known as the Foramen of Winslow).
○ It is demarcated anteriorly by the caudate lobe of the liver, the stomach and lesser
omentum. Posteriorly it is marked by the pancreas. Its left lateral margin is made by
the left kidney and adrenal gland. Its boundary on the right is made by the epiploic
foramen and lesser omentum.
• Greater sac- This is the general cavity of the abdomen or peritoneal cavity. It is connected
with the lesser sac via the omental foramen also known as the Foramen of Winslow or
Epiploic Foramen.
Describe the sources and distribution of arteries to important structures or
organs derived from the foregut, midgut and hindgut.
3 unpaired arteries arising from the anterior of the aorta
Stuart's Anatomy of the Abdomen and Pelvis Page 8
• Distinguishing features of large intestine from small intestine include fatty tags,
(appendices epiploicae), ribbons of longitudinal muscle (taeniae coli) and
segmented or pocketed walls. Diameter is not always a reliable guide.
• Sigmoid colon is so named because it is S shaped.
• Ileocecal orifice does not allow passage of waste back up- no defined sphincter
arrangement although it does passively stop waste returning.
• Transverse colon has a mesentery and therefore intraperitoneal with the sigmoid
colon.
Describe the sources and distribution of arteries to important structures or
organs derived from the foregut, midgut and hindgut.
3 unpaired arteries arising from the anterior of the aorta
• Coeliac trunk- Foregut, liver, pancreas and spleen.
• Superior mesenteric artery (SMA)= Midgut
• Inferior mesenteric artery (IMA)= Hindgut
Venous return, lymphatics and nerve fibres
Venous System
• All veins drain back to the liver.
• Liver will process the nutrients and pass them all back into the systemic
circulation.
• Portal vein= gut -> liver.
Splenic v
Portal vein
Inferior
mesenteric vein
Superior
mesenteric v
• Splenic vein drains into the superior mesenteric which drains into the portal
vein.
• The portal vein arises from the superior mesenteric and splenic veins posterior
to the 1st part of the duodenum/ pylorus of the stomach. It then runs in the
free edge of the lesser omentum to the liver.
Splenic v
Portal vein
Inferior mesenteric vein
Superior mesenteric v
Porto-systemic anastomoses
• The portal systemic anastomoses are where veins draining to the portal vein and
the IVC communicate.
• Liver or portal obstruction causes these veins to dilate widely, possibly leading to
severe haemorrhage from oesophagus or rectum.
A
• Inferior is the smallest one.
Coeliac trunk
• Supplies the entire foregut (lower oesophagus, stomach, upper duodenum) and its
derivatives (liver and part of pancreas). The spleen, though not part of the alimentary
system, develops close to the foregut and shares its blood supply from the coeliac trunk.
C
Coeliac
trunk
D
SIPEE
Common hepatic
artery
Stuart's Anatomy of the Abdomen and Pelvis Page 9
B
trunk
SIPEE
Common hepatic
artery
B
• The main branches of the Coeliac trunk are the Left Gastric Artery, Splenic Artery and the
Common Hepatic Artery.
•
•
•
•
Esophageal branches of left gastric - Esophageal branches of azygos vein.
Superior Rectal- Inferior Rectal
Paraumbilical -Epigastric
Portal on left systemic on right.
• Systemic circulation meets portal circulation.
• Varicose veins on the wall of the gut can bleed easily if you cough hard enough.
• This can happen if you are an alcoholic with an inflamed liver that diverts blood
to other channels.
• Portal hypertension.
GI Overview
Lymphatics:
Lymphatics
Thoracic
duct
Coeliac
nodes
Cisterna
chyli
Superior
mesenteric
nodes
Coeliac
trunk
Superior Mesenteric
Artery & vein
• This block of structures forms the posterior relations of the liver and stomach and is part of
the retroperitoneum.
• The aorta bifurcates at the level of L3 into the inferior mesenteric and then at L4 to common
iliac artery which means you cannot have an abdominal aortic aneurysm below the
umbilicus which rules out one diagnosis.
Superior Mesenteric Artery
• Branches include:
 Middle colic artery
 Right colic artery
 Ileocolic artery
 Jejunal arteries
 Ileal arteries
As in other parts of
the body, the
lymphatic drainage of
the bowel follows the
arterial supply, not
the venous drainage.
This is particularly
important in the gut,
where the two routes
are very different.
inferior
mesenteric
nodes
Nerves:
• Abdominal viscera is supplied by autonomic nervous system.
• Sensory fibres most important.
• Parasympathetic sensory (regulate reflex gut function)
○ Vagus Nerve
○ Pelvic Splanchnic Nerves (S2-S4)
• Sympathetic sensory (mediate pain)
○ Thoracic splanchnic (T5-T12)
○ Lumbar splanchnic (L1+L2)
Middle colic
artery
• Thoracic Splanchnic
N. (T5-T12)
Right colic
artery
• Greater Splanchnic N.
(T5-T9)
• Lesser Splanchnic N.
(T10-T11)
Jejunal
arteries
ileocolic
artery
Thoracic Splanchnic Ns.
• Lumbar Splanchnic
N. (L1 + L2)
• Least Splanchnic N.
(T12)
Ileal arteries
Inferior Mesenteric Artery
• The junction of the mid and hind gut is near the left splenic flexure of the colon. There is a
change from superior to inferior mesenteric artery supply at this level, but with anastomoses
between them.
Stuart's Anatomy of the Abdomen and Pelvis Page 10
• Innervation: the sensory fibres are most important.
• In the viscera the sensory fibres running with the sympathetic (T1 -L2) mediate
pain.
• Sensory fibres running with the parasympathetic (vagus or sacral) are involved in
reflex regulation of gut function.
• LSS arteries-:
 Left colic artery
 Superior rectal artery
 Sigmoidal artery
Stuart's Anatomy of the Abdomen and Pelvis Page 11
Liver, spleen and biliary system
15 May 2012
08:55
Learning Objectives
Basic anatomy- Some detail is taken from Instant Anatomy for android written by Dr.
Define the anatomical and functional lobes of the liver.
Robert Whitaker who teaches anatomy at Cambridge
Define the term “portal triad”.
Know the names and contents of the mesenteries associated with the liver and
spleen.
Draw a basic diagram of the biliary tree.
List the three major sites of porto-systemic anastomoses and their clinical
pathology in portal hypertension.
Know the anatomical relations of the liver and spleen.
Define the anatomical and functional lobes of the liver.
Anatomical- Divided into lobes by the falciform ligament
Functional- Divided into lobes dependent on vascular supply to portal triads, also defined by
the fossa for the gall bladder and the inferior vena cava.
• Largest organ in the body that weighs 1500g and takes 30% of cardiac output.
• Divided into two main lobes- use a line that goes through the falciform ligament
(anatomical division of the liver).
○ The right lobe of the liver lies between ribs 6-10/costal cartilages.
○ Whereas the left lobe lies from 6-7 costal cartilages.
Draw a basic diagram of the biliary tree.
R
L
Falciform Lig.
Common bile duct
Ligamentum Teres
Divided anatomically by the FALCIFORM LIGAMENT.
• R lobe is larger than left.
• Liver is enveloped by the ventral mesentery- LV- I LOVE THE LIVER.
Define the term “portal triad”.
• Common bile duct runs in free edge of the lesser omentum.
• Bile duct is 8cm long and wide.
• Ampulla of Vater opens into 2nd part of duodenum on posteromedual wall, 10cm
from pylorus. Also known as the major duodenal papilla and marks the site of
transition from foregut to midgut.
• Number 3 is the sphincter of Oddi which controls the flow of pancreatic exocrine
secretions through the ampulla of Vater.
• Common bile duct lies in the lesser omentum.
• Anteriorly joins liver and abdominal wall.
• Posteriorly joins transverse colon and 1st part of duodenum.
R hepatic duct
Functional liver architecture
• Liver can be divided functionally into segments supplied by portal triads and the fossa for
gall bladder and IVC.
• Line going through fossa of gall bladder and IVC.
• The quadrate lobe is the weird bit on top.
• Caudate lobe is the lobe in between.
• Portal triad- Functional area of the liver containing a bile duct, hepatic artery and portal
vein.
Gallbladder
Quadrate Lobe
Anterior
L hepatic duct
Common hepatic duct
R
Pancreatic duct
Cystic duct
L
Common bile duct
Posterior
Porta Hepatis
Duodenum
Spleen
•
•
•
•
•
•
•
•
Lies behind the ribcage and cannot be felt unless it is grossly enlarged.
Extremely vascular organ.
1 inches thick
3 inches wide
5 inches long
Weighs 7oz
Lies behind ribs 9-11
Quite a tense organ and therefore ruptures easily.
IVC
Caudate Lobe
• Porta hepatis is the area on the under surface of the liver at which the structures in the
•
•
•
•
free edge of the lesser omentum enter/leave the liver, (hilum of the liver) contains the,
portal vein, hepatic artery and bile duct.
Bare area of the liver- enlarges slightly out of the peritoneum directly in contact with the
diaphragm.
Be aware above that that is an inferior view I.e looking up at it from feet so bile duct and
quadrate lobe are actually more inferior in a typical anterior view.
The quadrate lobe is functionally part of the left lobe
The caudate lobe is functionally independent of both lobes.
Bare Area
Diaphragm
Subphrenic Recess
Hepatorenal
recess
Stuart's Anatomy of the Abdomen and Pelvis Page 12
Subphrenic Recess
Hepatorenal
recess
List the three major sites of porto-systemic anastomoses and their clinical
pathology in portal hypertension.
Posterior
Anterior
R. Kidney
• Fibrotic liver disease- causes portal hypertension which means that when portal
and systemic are joined, nutrients, bacteria etc will move to the systemic
circulation without processing. Is bad!
Tributaries to Azygos V.
• Subphrenic and hepatorenal recesses created by foldings of peritoneum. Fluid in the
abdomen will tend to collect in these areas because the patient is lying down.
Know the vascular supply/drainage of the liver, spleen and gallbladder.
Liver
Left Gastric V.
Paraumbilical Veins
Superficial Veins
on abdominal wall
Sup. Rectal Vein.
Blood supply
Coeliac axis
• Left gastric
• Splenic
• Common hepatic- runs with the bile duct and portal vein in the free edge of the lesser
omentum. Branches are:
○ Cystic
○ Left hepatic
○ Right hepatic
Internal Illiac Vs.
R. Hepatic
Inf. Rectal Vs.
The Coeliac Axis
Calot’s Triangle
L Hepatic
L. Hepatic
1. Paraumbilical veins- Superficial veins on abdominal veins. (They can become very
dilated) Caput medusae.
2. Superior rectal veins- Inferior rectal veins- haemorrhoids development
3. Left gastric vein-tributaries of azygos vein- Clinically most important, bleeding
oesophageal varices massive vomiting of blood- especially bad as they are likely to
have liver disease therefore poor clotting factors.
Left Gastric
R Hepatic
Common
Hepatic
Cystic
L. Gastric
Splenic
Common
Hepatic
Splenic
Know the names and contents of the mesenteries associated with the
liver and spleen.
• Mesentery- Two layers of peritoneum that are closely reflected to each
other.
• Conduit for arteries, veins, nerves and lymphatics supplying viscera.
• Bag metaphor imagine pushing your hand into a bag but the outside.
Ventral and Dorsal Mesenteries
Aorta
Cystic A.
• Calot's triangle- Cholecystectomy- need to be careful when you clip off the artery that
you do not clip off the common bile duct. Borders are:
○ Cystic duct
○ The common and right hepatic ducts
○ The inferior edge of the liver
• Calot's triangle contains:
○ Cystic artery
○ Sometimes right hepatic artery
○ Calot's lymph node- enlarged in cholecystitis.
Spleen
• Ligament- Piece of peritoneum that attaches to viscera.
• Lesser omentum= Gastric hepatic + hepato-duodenal ligaments.
1. Gastro-hepatic
○ Contains right and left gastric arteries.
2. Hepato-duodenal ligament
○ This contains the portal triad-portal vein, hepatic artery and bile duct.
○ Runs from 1st part of duodenum to liver.
3. Falciform ligament
○ Runs from liver to anterior abdominal wall
4. Ligament teres○ The free, thickened edge of the falciform ligament and contains the
remnant of the umbilical vein which is now obliterated.
5. Gastro-splenic ligament (gastrolienal)
○ Contains short gastric vessels and left gastro-omental vessels.
6. Spleno-renal ligament
○ Contains tail of pancreas and splenic artery and vein.
Splenic Artery
• The splenic artery reaches the spleen by travelling in the spleno-renal ligament.
Portal circulation
Portal V.
Anterior/Ventral
Falciform
Ligament
Stuart's Anatomy of the Abdomen and Pelvis Page 13
Liver
Splenic V.
6. Spleno-renal ligament
○ Contains tail of pancreas and splenic artery and vein.
Portal circulation
Portal V.
Anterior/Ventral
Splenic V.
Falciform
Ligament
Liver
Lesser Omentum
- Gastrohepatic lig
- Hepatoduodenal lig
Stomach
Gastrosplenic
Ligament
Spleen
Sup. Mesenteric V.
Inf. Mesenteric V.
Splenorenal
Ligament
• The portal vein is formed from the Superior mesenteric vein and Splenic vein posterior to
the neck of the pancreas at L2 level.
• Filter bacteria from GI tract.
• Metabolise all carbohydrates fats etc
• Transport of amino acids straight to the brain causes dementia/encephalopathy due to
ammonia.
Kidneys
Posterior/Dorsal
Lesser
omentum
Portal V.
Left Gastric V.
Splenic V.
Sup Mesenteric V.
Inf Mesenteric V.
CLOCKWISE rotation of the stomach along its longitudinal axis
results in the right side of the peritoneal cavity becoming
POSTERIOR – the OMENTAL BURSA (= LESSER SAC)
ANTERIORLY (originally LEFT) is the GREATER SAC.
• The lesser sac is in the posterior part of the peritoneal cavity and is directly in
front of the retroperitoneal organs including the pancreas, great vessels,
duodenum and kidneys.
Lesser Omentum
Lesser Omentum
Lesser Curvature of
Stomach
Gallbladder
Omental
Foramen
Stomach
Duodenum
• Free edge of lesser omentum contains:
○ Portal vein
○ Bile duct
○ Hepatic artery
Stuart's Anatomy of the Abdomen and Pelvis Page 14
• Left gastric vein drains the fundus of the stomach.
• Blood drains from the liver directly into IVC via 3 short hepatic veins.
Retroperitoneum
15 May 2012
08:55
Learning Objectives
Define the terms intraperitoneal, retroperitoneal and secondarily
retroperitoneal.
Define the terms intraperitoneal, retroperitoneal and secondarily
retroperitoneal.
Intraperitoneal- Structures suspended from abdominal wall by mesenteries (e.g. most of
small bowel)
Retroperitoneal- Structures lying posterior to parietal peritoneum (e.g. kidneys and great
vessels)
Secondary retroperitoneal- * These organs originally had a mesentery, then became
secondarily retroperitoneal when the mesentery fused with the body wall.
List the retroperitoneal organs.
Demonstrate and name the major branches of the abdominal aorta
Draw a basic diagram of the great vessels, kidneys, duodenum and pancreas.
List the retroperitoneal organs.
Name the major abdominal lymph nodes and outline their pattern of drainage.
Demonstrate and name the major branches of the abdominal aorta
•
•
•
•
•
•
•
•
Coeliac trunk-Supplies the Foregut
Superior mesenteric artery- Supplies the Midgut
Renal arteries- Kidneys
Inferior mesenteric artery- Supplies the Hindgut
Retroperitoneal structures:
Primary
Suprarenal glands (the adrenals)
Kidneys
Ureter
Bladder
Aorta
IVC
Esophagus
Rectum (part, lower 3rd is
extraperitoneal
Secondary *
• The head, neck, and body of the pancreas
but not the tail which is located in
the splenorenal ligament.
• Duodenum apart from the proximal
first segment which is intraperitoneal
• Ascending and descending portions of
colon (but not the transverse or cecum)
Intraperitoneal organs
• Stomach
• 1st and 4th part of duodenum
• Jejunum
• Ileum
• Cecum
• Appendix
• Transverse Colon
• Sigmoid Colon
• Rectum (Upper 1/3)
• Liver
• Spleen
• Tail of pancreas
In women- Uterus, Fallopian Tubes,
Ovaries
• Good memory aide is SAD PUCKER.
•
R Kidney
Adrenal Glands
L Kidney
Pancreas
Duodenum
IVC
Abdominal
Aorta
Ureters
Foregut- Distal 3rd of oesophagus to the duodenum at the entrance of the bile
duct ((Major duodenal papilla .
Midgut- Major duodenal papilla to two-thirds along transverse colon.
Hindgut- Distal third of transverse colon to the rectum.
Veins are always anterior to arteries.
Draw a basic diagram of the great vessels, kidneys, duodenum and
pancreas.
Coeliac Axis – L1
SMA – L1
Stuart's Anatomy of the Abdomen and Pelvis Page 15
Draw a basic diagram of the great vessels, kidneys, duodenum and
pancreas.
Pancreas
Embryology
• The pancreas develops as a ventral and dorsal bud in the ventral and dorsal
foregut mesenteries respectively and therefore starts intraperitonealy.
• The smaller ventral bud rotates clockwise to become dorsal and associated
with the dorsal pancreatic bud.
• Also the superior mesenteric vein becomes trapped between the two and
the buds fuse to become secondary peritoneal, except for the tail which lies
in the splenorenal ligament. The original ventral bud is now called the
uncinate process.
• Furthermore the embryology of the pancreas also explains why there is an
accessory pancreatic duct in addition to the main one.
SMA – L1
IMA – L3
Uncinate
process
Superior
mesenteric V.
Renal Vasculature
IVC
Superior
mesenteric A.
• Superior mesenteric vein and superior mesenteric artery are trapped
between the uncinate process and the neck of the pancreas.
Visceral relations of the Kidneys
SMA
R. Adrenal Gland
L. Adrenal Gland
Stomach
Pancreas
Liver
Right Renal A.
Spleen
Splenic
Flexure
Left Renal A.
Right Renal V.
Left Renal V.
2nd part of
duodenum
Descending
Colon
Hepatic
Flexure
• Renal vessels arise at approximately L1- the transpyloric plane
• Left renal vein is longer than right renal vein and runs posterior to SMA but
anterior the left renal artery. Aneurysms of SMA cause nutcracker
syndrome.
○ Note this is slightly weird because we usually say that veins lie anterior
to arteries but this is a branch of the main aorta so that’s why it is ok for
it to be weird and be posterior to the SMA.
Duodenum
Jejunum
Name the major abdominal lymph nodes and outline their pattern of
drainage.
Sup. Mesenteric Nodes
Coeliac Nodes
Collectively = PARA-AORTIC NODES
Lymphatic drainage follows the
ARTERIES.
Thoracic Duct
Cisterna Chyli
Coeliac Nodes
Sup. Mesenteric Nodes
Inf. Mesenteric Nodes
• Note that tail of pancreas and the spleen are intraperitoneal structures.
• Duodenal areas:
i. Superior / first part – duodenal cap, common place for peptic
ulcers. Passes anteriorly to bile duct, gastroduodenal artery, portal
vein and IVC.
ii. Descending / second part – contains minor and major duodenal
papillae where accessory pancreatic duct and bile duct enter
respectively.
iii. Inferior / third – part – crosses IVC and has SMA anterior to it.
iv. Ascending / fourth part – terminates at duodenojejunal flexure.
Stuart's Anatomy of the Abdomen and Pelvis Page 16
Inf. Mesenteric Nodes
• Onblock resection- Reduces rates of recurrence in malignancy.
• Divisions of para-aortic nodes cannot be done accurately in vivo.
• Cisterna Chyli is a dilated sac at the inferior end of the thoracic duct which empties
into the junction of the left subclavian and left internal jugular veins in the thorax.
Note the thoracic duct is found in the posterior mediastinum in the thorax and enters
the abdomen through the aortic hiatus.
Urinary System and Abdominal Ultrasound
17 May 2012
08:51
Learning Objectives
Demonstrate and draw the principal relations of the duodenum, pancreas and
kidneys including major vascular relations.
Name the main organs in contact with each of the left and right kidneys
Demonstrate and draw the principal relations of the duodenum, pancreas and
kidneys including major vascular relations.
Name the main organs in contact with each of the left and right kidneys
Describe the arterial supply of the kidneys and adrenal (suprarenal) glands
Describe the arterial supply of the kidneys and adrenal (suprarenal) glands
Reminder- Retroperitoneal organs are- SADPUCKER
Mark the likely positions of the kidneys and ureters in a living subject and
demonstrate their positions in appropriate plain and contrast radiographs and in
CT images.
Demonstrate how to palpate the kidneys in a living subject.
Demonstrate the main components of the posterior abdominal wall from
diaphragm to pelvic inlet.
Suprarenal glands, Aorta/IVC, Duodenum (not 1st part), Pancreas (all apart from tail) Urinary
tract, Colon (descending + ascending), Kidneys, Esophagus, Rectum.
Kidneys
• Lie on posterior abdominal wall, adjacent and parallel to psoas muscle.
• Left usually a little higher than right due to liver.
• Approximately 10-12cm in size (3-4 lumbar vertebrae)
• Surrounded by perinephric fat and renal fascia (Gerota's fascia)- open inferiorly.
○ Blood can go right down into the pelvis because of this.
R. Adrenal Gland
Imaging Modalities
Plain abdominal X-Ray
• Gas, fat, soft tissue and calcium/metal are the only 4 radiographic densities.
• Renal and bladder outlines only visible because of surrounding fat.
• Frequently obscured bowel gas.
• Abdominal vessels not visible unless calcified.
• Most renal and ureteric stones visible (85% calcified)
Intravenous urogram/pyelogram
• Control images essential
• Iodine containing water soluble contrast given I.V
• Filtered by the kidney into the collecting system.
• Standard sequence of images taken.
• Immediate-nephrogram phase- contrast in the glomeruli and proximal tubules.
•
•
•
•
Delayed images- 5mins, 10mins, 15mins
May put compression on abdomen to distend the pelvicalyceal system
Release image to show ureters and bladder
Post micturition image of bladder.
•
•
•
•
•
Control images essential
Iodine containing water soluble contrast given I.V
Filtered by the kidney into the collecting system.
Standard sequence of images taken.
Immediate-nephrogram phase- contrast in the glomeruli and proximal tubules.
L. Adrenal Gland
Stomach
Spleen
Pancreas
Liver
Splenic
Flexure
2nd part of
duodenum
Descending
Colon
Hepatic
Flexure
Jejunum
Relation of kidneys- Right
• Anterior- Peritoneum, right lobe of liver, duodenum, colon, hepatic flexure
• Posterior- diaphragm, quadratus lumborum
• Lateral- abdominal wall
• Medial- Psoas major muscle, IVC, gonadal veins, ureter.
Relation of kidney Left
• Anterior- Peritoneum, stomach, splenic flexure, tail of pancreas, small bowel, spleen
• Posterior- diaphragm, quadratus lumborum
• Medial- Aorta, gonadal veins, psoas major, ureter.
• Veins lie anterior to the arteries and there may be multiple renal arteries.
• Veins are bigger than arteries- veins are flat and irregular arteries are nice and round.
• Right renal vein shorter than left renal vein.
• Usually quite a bit of fat inbetween right kidney and adrenal so a lot higher up.
• Left adrenal is usually more medial and slightly lower down.
Ureter
• Runs from renal pelvis to bladder and is approximately 25 cm long.
• Lies on the medial edge of psoas in abdomen and enters pelvis by crossing common
iliac vessels.
• Ureter crosses in front of veins and arteries.
• Runs along lateral pelvic wall and enters bladder posteriomedially at bladder base at
edge of the trigone.
20 min release image
CT Urogram
Post micturition image
• Consider radiation dose
• Is there a need for a pre contrast scan to look for stones
Ultrasound
• No contrast or radiation, good for renal size, hydronephrosis, stones , some tumours,
but relies heavily on whether the operator is good or not.
Demonstrate the main components of the posterior abdominal wall from
diaphragm to pelvic inlet.
The Kidney Congenital Variants
Urinary bladder
• Midline structure covered superiorly by peritoneum.
• Superior relations- Small bowel and sigmoid colon
• Anteriorly- Pubic symphysis
• Laterally- Levator ani and obturator internus
• Circular muscle in the wall condenses to form internal urethral sphincter at bladder
neck.
Horseshoe kidney• The kidneys are close together in the embryonic pelvis. In approximately 1 in 600
fetuses, the inferior poles (rarely, the superior poles) of the kidneys fuse to form a
horseshoe kidney
• This U-shaped kidney usually lies at the level of L3–L5 vertebrae because the root of the
inferior mesenteric artery prevented normal relocation of the kidneys.
• Horseshoe kidney usually produces no symptoms; however, associated abnormalities
of the kidney and renal pelvis may be present, obstructing the ureter
Stuart's Anatomy of the Abdomen and Pelvis Page 17
•
•
•
•
•
Midline structure covered superiorly by peritoneum.
Superior relations- Small bowel and sigmoid colon
Anteriorly- Pubic symphysis
Laterally- Levator ani and obturator internus
Circular muscle in the wall condenses to form internal urethral sphincter at bladder
neck.
fetuses, the inferior poles (rarely, the superior poles) of the kidneys fuse to form a
horseshoe kidney
• This U-shaped kidney usually lies at the level of L3–L5 vertebrae because the root of the
inferior mesenteric artery prevented normal relocation of the kidneys.
• Horseshoe kidney usually produces no symptoms; however, associated abnormalities
of the kidney and renal pelvis may be present, obstructing the ureter
• Horseshoe kidney results in a higher chance of hypertension and renal calculi.
Female
• Uterus and cervix lie posteriorly in the midline. Position of the uterus is very variable –
anteverted, retroverted, affected by the degree of bladder filing
• Ureters enter the bladder base around the cervix
• Urethra - very short - anterior to the vagina
• Ovaries - lie on the pelvic side wall on the iliac vessels but may “fall” into the pouch of
Douglas or be displaced anteriorly and laterally . 1- Rectus Abdominis
2- Urinary Bladder
3- Vagina
4- Ureter/ Round ligament
5- Body of uterus
6- Cervix
7- Colon
8- Vertebrae
Note sure if those labels are
correct so you may want to
check, but they seemed to
fit and make sense.
http://sprojects.mmi.mcgill.ca/gyn
ecology/anatsagfrmd.htm
Duplex collecting system
• Embryologically, duplication occurs when two separate ureteric buds arise from a single
Wolffian Duct.
• Radiographical features may include duplicated ureters extending a variable distance
down to the bladder and obstruction of the upper pole moiety down to the bladder,
often with a ureterocoele.
• Pain in the back may occur after drinking excessively.
Male
• Prostate lies inferiorly at the bladder base– surrounds the prostatic urethra
• Seminal vesicles lie on either side of the bladder base- vas deferens
5
1- Urinary Bladder
• Urethra
7
2- Prostrate gland
6
1
3- Urethra
4- Anus
5- Vertebrae
6- Colon
7- Rectus Abdominis
2
Note sure if those labels are
correct so you may want to
check, but they seemed to
fit and make sense.
3
Others:
• Additional disorders may include an extra renal artery and a pelviureteric junction
obstruction.
Renal colic- On a radiograph black fluid will be trapped behind a stone which will be
relatively white.
4
Cystourethrography
• Retrograde urethography - inject contrast via the urethral meatus
• Antgrade urethrography - fill bladder with contrast (usually via a catheter as too dilute
after an IVU). Fluoroscopy with spot images during voiding
• Possible to measure bladder and rectal pressures during voiding to get an idea of
function.
Aorta
Imaging Modalities
•
•
•
•
Extends from diaphragmatic hiatus to bifurcation at level of 4th lumbar vertebra
< 50 yrs - should be < 2 cm in diameter
>50 yrs - considered aneurysmal if > 3 cm
Divides into R and L common iliac arteries which divide into internal and external iliac
arteries.
• Also midline median sacral branch
Abdominal Arteriography
•
•
•
•
•
Local anaesthetic in groin over the palpable femoral artery
Puncture femoral artery ( usually Rt)
Pass guide wire through needle up the femoral and iliac arteries into the aorta
Remove needle leaving guide wire in place
Pass catheter over guide wire into aorta
• Aortogram - injection of contrast into aorta
• Selective renal / coeliac / mesenteric arteriogram - manipulate catheter tip into origin of
the appropriate vessel and then inject contrast
• DSA (digital subtraction angiogram) - electronically subtract the background to display
only contrast in the vessels.
Coeliac Axis
Major Paired Branches
○ Renal arteries
 May be more than one to each kidney
 Arise anterolaterally at approximately same level as SMA- lower border of L1
 Right renal artery passes behind IVC
 (Left renal vein passes anterior to the aorta)
Gonadal arteries
Stuart's Anatomy of the Abdomen and Pelvis Page 18
Venous Phase
○
○
○
○
 (Left renal vein passes anterior to the aorta)
Gonadal arteries
Adrenal arteries
Phrenic arteries
Lumbar arteries
Arterial Phase
Superior Mesenteric Artery
Anterior branches:
• Coeliac Axis - stomach, liver, spleen, pancreas and duodenum
• Superior mesenteric - small bowel and colon to splenic flexure
• Inferior mesenteric to distal colon and rectum
Demonstrate how to palpate the kidneys in a living subject.
• The kidneys are often impalpable. In lean adults, the inferior pole of the right
kidney is palpable by bimanual examination as a firm, smooth, somewhat rounded
mass that descends during inspiration. Palpation of the right kidney is possible
because it is 1–2 cm inferior to the left one.
• To palpate the kidneys, press the flank (side of the trunk between the 11th and
12th ribs and the iliac crest) anteriorly with one hand while palpating deeply at
the costal margin with the other. The left kidney is usually not palpable unless it is
enlarged or a retroperitoneal mass has displaced it inferiorly.
Stuart's Anatomy of the Abdomen and Pelvis Page 19
Arterial Phase
Venous Phase
Multiplanar CT scans showing an aortic aneurysm
Visceral Pain
22 May 2012
08:54
Learning Objectives
Describe the origins and pathways by which autonomic nerves reach the abdomen.
Describe the origins and pathways by which autonomic nerves reach the
abdomen.
Discriminate between the distributions and motor functions of the
sympathetic and parasympathetic nerves in the abdomen.
Compare the sensory functions of the sympathetic and parasympathetic
nerve supplies in the abdomen.
Outline the segmental pattern of pain fibre distribution to the abdominal
viscera.
Explain the concept of referred pain and identify the most probable sites to
which pains of abdominal visceral or diaphragmatic origin are likely to be
referred.
Sympathetic nervous system- arises from the T1-L2 spinal cord segments.
Parasympathetic nervous system- arises from cranial nerves, III, VII, IX, X (oculomotor, facial,
glossopharyngeal and vagus) and spinal cord segments S2-S4.
Discriminate between the distributions and motor functions of the sympathetic and
parasympathetic nerves in the abdomen.
Afferent:
• Sympathetic: pain
• Parasympathetic: specific functional
sensation e.g. stretch
Efferent
• Motor to smooth muscle
• Secretomotor to glands
Sympathetic from T1 – L2
Lt vagus n
(Rt vagus not shown)
Outline the segmental pattern of pain fibre distribution to the abdominal viscera.
Rt sympathetic trunk
(Lt trunk not shown)
Explain the concept of referred pain and identify the most probable sites to which
pains of abdominal visceral or diaphragmatic origin are likely to be referred.
• The brain cannot localise pain sensation from structures for which there is no map in the
cortex. These structures are the visceral organs and the diaphragm.
• In these cases pain is referred to the regions of skin supplied by nerves with the same
segmental supply (dermatomes)
• In the abdomen, the nerve supply to the organ is autonomic.
Dermatome
• Area of skin supplied by a single spinal nerve (i.e. single segment of the spinal cord)
• Adjacent dermatomes overlap so that on the trunk, at least three spinal nerves would have to
be blocked to produce a region of complete anaesthesia.
• No C1 dermatome.
Note:
No C1 dermatome.
Anterior (left) &
posterior (right)
vagal trunks
Diaphragm
Splanchnic nerves
Coeliac ganglion
Splanchnic = visceral
• Vagus travels along oesophagus in the abdominal region.
• Ganglia are named according to the major blood vessels supplying the GI tract.
Sympathetic chain
Nerve pathways from the sympathetic
chain to the abdomen
Diaphragm
Diaphragm
Greater
Greatersplanchnic
splanchnic nerve
nerveT5-9
T5-9
Lesser
Lessersplanchnic
splanchnic nerve
nerveT10-11
T10-11
Nerves
Nerves from
from lumbar
lumbar
sympathetic
sympathetic chain
chain
Least
Leastsplanchnic
splanchnic nerve
nerveT12
T12
Splanchnic
Splanchnic== visceral
visceral
Parasympathetic- Vagus nerve (CN X) and Sacral Outflow S2-S4 are the main supplies of the viscera.
Referred Pain from Midgut Structures
Peripheral vessels and skin- Nerves run with somatic nerves to same region (sympathetic only)
Compare the sensory functions of the sympathetic and parasympathetic nerve
supplies in the abdomen.
Autonomic plexuses and ganglia
Afferent pain fibres from
midgut structures enter
the spinal cord at T10
segment.
Skin of umbilical region
is also supplied by T10
spinal nerve
Umbilical pain: pain from midgut structures (from
duodenal papilla to splenic flexure) including inflamed
appendix referred to periumbilical region. It is usually
colicky (intermittent with bowel contractions)
• The autonomic nerves to the abdomen are routed via plexuses surrounding the aorta and its
branches.
• Sympathetic nerves synapse at ganglia associated with these plexuses.
• Plexuses and ganglia are named according to the associated blood vessels.
• Plexus- Interconnecting network of nerves
Plexus
Anterior (left) Vagal trunk
Ganglia & trunks
Superior mesenteric
ganglion
Coeliac trunk & ganglion
Renal plexus & ganglion
Stuart's Anatomy of the Abdomen and Pelvis Page 20
Inferior mesenteric
ganglion
is also supplied by T10
spinal nerve
Umbilical pain: pain from midgut structures (from
duodenal papilla to splenic flexure) including inflamed
appendix referred to periumbilical region. It is usually
colicky (intermittent with bowel contractions)
Plexus
Anterior (left) Vagal trunk
Ganglia & trunks
Superior mesenteric
ganglion
Coeliac trunk & ganglion
• When the inflammation of the appendix spreads to the surrounding peritoneum the pain
becomes localised and constant at the right inguinal region. Movement of the hip joint and
coughing elicits pain.
Foregut structures
• Epigastric pain- pain from foregut structures (as far as duodenal papilla) is referred to this
region. Structures involved: Stomach, proximal duodenum, pancreas, liver, gall bladder. T7/T8
Hindgut structures
• Suprapubic (hypogastric) pain: pain from hindgut structures descending colon to anal canal is
referred here.
T7-8
T10
Renal plexus & ganglion
Inferior mesenteric
ganglion
Sympathetic trunk
& ganglion
Superior hypogastric
plexus
Inferior hypogastric
plexus
Parasympathetic
nerves from vagus (X)
To organs supplied by:
Sympathetic nerves
from sympathetic
chain (T5-L2)
Superior mesenteric
artery T10-11 / X
T11-L2
Coeliac artery T5-9 / X
Renal arteries
T10-12 / X
Testicular/ovarian
arteries T10-11 / X
Foregut- Epigastric- T7/T8
Midgut- Umbilical- TX
Hindgut- Suprapubic- T12/L1-L2
Inferior mesenteric
artery T12-L2 / S2-4
Parasympathetic
nerves from sacral
outflow (S2-4)
Stuart's Anatomy of the Abdomen and Pelvis Page 21
Superior and inferior
hypogastric plexuses
T12-L2 / S2-4
Non- Reproductive Peritoneum
22 May 2012
08:54
Learning Objectives
Introduction
Define the pelvic floor, identify its nerve supply and indicate its importance.
Describe the course of the ureters from the renal pelvis to the entry into
the urinary bladder
The Pelvic Girdle
Describe the relations of the ureters to the uterine arteries and the cervix
Describe the shape, position and relations of the bladder in the male and
female pelvis
Left hip bone
Right hip bone
Explain the anatomical relations of the full urinary bladder
Sacrum
Describe the shape, relations and arterial supply of the rectum
Pubic angle
2/29
• Sacro-ilial join is a synovial joint.
• 2 foramen- Obturator foramen and Pelvic angle.
Right Hip Bone
Acet
Fossa
• All 3 bones meet in the acetabulum.
• In a child they would not all be fused.
Right Hip Bone & Sacrum
Posterior
Iliac fossa
sacrum
Pelvic wall:
Sacrum & coccyx,
pelvic bones
coccyx
Sacrospinous and
sacrotuberous
ligaments
Medial view
• Child during birth has to leave through pelvic inlet.
• Siatic notches are the curved parts of pelvis that are divided by the
sacrospinous ligament.
Abdominopelvic Cavity
Axis of abdominal cavity
Describe the course of the ureters from the renal pelvis to the entry into the
Pelvic inlet
Stuart's Anatomy of the Abdomen and Pelvis Page 22
Axis of pelvic
Abdominopelvic Cavity
Axis of abdominal cavity
Describe the course of the ureters from the renal pelvis to the entry into the
urinary bladder
• The ureters are muscular tubes that transport urine from the kidneys to the bladder.
• They are continuous superiorly with the renal pelvis, which is a funnel -shaped structure in
the renal sinus.
• The renal pelvis is formed from a condensation of two or three major calices, which in
turn are formed by the condensation of several minor calices. The minor calices surround
a renal papilla.
• The renal pelvis narrows as it passes inferiorly through the hilum of the kidney and
becomes continuous with the ureter at the ureteropelvic junction.
• Inferior to this junction, the ureters descend retroperitoneally on the medial aspect of the
psoas major muscle.
• At the pelvic brim, the ureters cross either the end of the common iliac or the beginning
of the external iliac arteries, enter the pelvic cavity, and continue their journey to the
bladder.
Pelvic inlet
Axis of pelvic
cavity
Perineum
Pelvic outlet
The pelvic cavity is coloured red. Note that its axis is
angled about 450 back from the abdominal cavity (blue).
Pelvic cavity
• The iliac fossae form a shallow basin containing lower abdominal viscera.
• The axis of the pelvic cavity is antero-inferiorly incline.
• Pelvic cavity is conical or cylindrical (birth canal)
• Cavity is mainly lined by muscles and nerves.
Define the pelvic floor, identify its nerve supply and indicate its
importance.
Pelvic Wall Muscles and Ligaments
Two muscles are attached
to the medial surface of the
greater trochanter of femur
Constriction of the ureters can occur at:
1. Ureteropelvic junction
2. Where the ureters cross the common iliac vessels at the pelvic brim/
3. Where the ureters enter the wall of the bladder.
Sacrospinous ligament
Sacrotuberous ligament
Medial aspect of right pelvic wall
• As a result kidney stones (renal calculi) can become lodged at these areas.
Describe the relations of the ureters to the uterine arteries and the cervix
• In the pelvis, the ureter is crossed by:
1. The ductus deferens in men
2. The uterine artery in women.
• The pelvic floor is formed by the pelvic diaphragm and, in the anterior midline,
the perineal membrane and the muscles in the deep perineal pouch.
• The pelvic diaphragm is formed be the levator ani and the coccygeus muscles
from both sides.
• The pelvic floor separates the pelvic cavity, above, from the perineum, below.
Pelvic diaphragm- This is the muscular part of the pelvic floor.
• Shaped like a bowl or funnel and attached superiorly to the pelvic walls, it
consists of the levator ani and coccygeus muscles.
Describe the shape, position and relations of the bladder in the male and
female pelvis
Ureter
Ductus deferens
Urogenital diaphragm
Prostate gland
The Pelvic Wall
Medial aspect of right pelvic wall
Ligaments not shown
Sagittal section
Male Pelvis
Levator ani
Stuart's Anatomy of the Abdomen and Pelvis Page 23
Most of the pelvic bone facing the pelvic cavity is
covered by the obturator internus muscle and
its fascia
Male Pelvis
Levator ani
Most of the pelvic bone facing the pelvic cavity is
covered by the obturator internus muscle and
its fascia
• Lumbosacral plexus supplies the lower limbs.
Pelvic Diaphragm/ Pelvic Floor
Coronal section
Coronal section of male pelvis showing how the urinary
bladder and prostate sit in the ‘bowl’ formed by Levator
ani. The fat-filled space labelled IF is the ischio-anal
fossa
• The muscle groups are collectively known as Levator ani which is very
important in determining faecal continence.
• The three muscles that make up levator ani are:
a. Iliococcygeus
b. Pubococcygeus
c. Puborectalis
• Obturator interus forms a tendonous arch.
• Fat filled fossa allows anal canal to expand
Internal urethral sphincter
(smooth muscle)
Anococcygeal ligament
Tendinous arch
(of obturator internus fascia)
Obturator
internus
coccygeus
External urethral sphincter
(skeletal muscle)
Medial aspect of right pelvic wall & floor
Urethra = 20 cm
The Pelvic Diaphragm
Medial aspect of right pelvic
wall & floor
• Urethra can be damaged at 1st bend.
• Easiest way to insert a catheter is by lifting the penis so it is straight which removes
one of the bends
Pudendal nerve
Female Pelvis
Ureter
ovary
The pelvic diaphragm consists of a bowl-like pair of skeletal
muscles: Levator ani, which support the pelvic organs (bladder,
cervix/uterus and rectum)
Nerve supply: Pudendal (S2-4) & directly by S4
Pelvic Diaphragm
Uterus
Anterior
Inferior view
U.bladder
Urethra = 4 cm
Ischio pubic ramus
Levator ani
Anal canal
Urethra
Urethral opening
Perineal
Membrane
Vaginal opening
vagina
(Only in female)
Perineal body
(fibromuscular mass)
Urethral Sphincters- female
Urethra
•Two additional groups of
muscles in females:
1. Sphincter
urethrovaginalis
Urethral orifice
Vagina
Stuart's Anatomy of the Abdomen and Pelvis Page 24
Anal opening
•In females internal
urethral sphincter is not
well organized
•External urethral
sphincter is skeletal
muscle surrounding the
urethra in the deep
perineal pouch
External
urethral
sphincter
Levator ani
2. Compressor urethrae
This view of the pelvic diaphragm illustrates the
openings in Levator ani for the urethra, vagina (in
female) and anal canal.
• Thick fascial sheet called perineal membrane- occupies anterior part.
• Because of vagina in women the structure is weaker.
• Keystone that has to be preserved during surgery- perineal body.
Pelvic floor and perineum
• A bowl like sheet of muscle called levator ani that forms the pelvic
diaphragm.
• Slung from the pelvis and sacrum.
perineal pouch
•Two additional groups of
muscles in females:
1. Sphincter
urethrovaginalis
Urethral orifice
Vagina
Pelvic floor and perineum
• A bowl like sheet of muscle called levator ani that forms the pelvic
diaphragm.
• Slung from the pelvis and sacrum.
• Supports the main pelvic viscera (bladder, uterus, rectum)
• Below the diaphragm is the Perineum, containing voluntary sphincters and
external genitalia.
2. Compressor urethrae
Explain the anatomical relations of the full urinary bladder
Describe the shape, relations and arterial supply of the rectum
The Rectum
Levator ani
‘Rectum’ is Latin for ‘straight’, but the human rectum has
a double-S bend, probably functioning as an anti-gravity
device keeping load off the sphincter
• Superior rectal artery is an offshoot of the Inferior Mesenteric Artery
The Rectum and Anal Canal
• The apex of the bladder is directed toward the top of the pubic symphysis; a structure
known as the median umbilical ligament continues from it superiorly up the anterior
abdominal wall to the umbilicus.
The Urinary Bladder
Anorectal junction
Anal
canal
Anterior
The rectum is supplied by the autonomic NS and is
mainly sensitive to filling. The anal canal is supplied by
somatic nerves and is extremely sensitive to injury.
Anterior
The Rectum and Anal Canal
The tetrahedral bladder has a structure at each corner
• The bladder is the most anterior of the pelvic viscera. Despite being part of the pelvic
cavity when empty, it expands superiorly when full into the abdominal cavity.
• Tetrahedral when empty
• Ureters enter at supero-posterior angles
• Urethra leaves through inferior angle
• Superior surface covered in peritoneum
• Expands between transversalis fascia and lining peritoneum
• Smooth muscle sphincter (vesicae) at neck
• Skeletal muscle sphincter (urethrae) in perineum
Anterior
The skeletal muscle sphincter ani surrounding the anal
canal is much less important to faecal continence than
the puborectalis part of Levator ani, which puts a sharp
angle into the recto-anal junction. Can be injured in a
badly-performed episiotomy
Qu. 1: Which artery supplies pelvic organs (not ovaries and testis)?
• Puborectalis- Forms a loop around the rectum which puts in a sharp junction which helps
to ensure continence.
External Iliac artery
Inferior mesenteric artery
Obturator artery
X Internal Iliac artery
None of the above
X Mark = -6 (conf=3 )
Best Option: Obturator artery
The best answer is obturator artery. The pelvic organs are supplied by named branches
of the internal iliac, not by the internal iliac artery itself. The obturator and iliolumbar
Stuart's Anatomy of the Abdomen and Pelvis Page 25
Rectum and Anal Canal
•
•
•
•
•
•
Rectum descends within concavity of sacrum
Shows three lateral curvatures
Right-angle bend back at recto-anal junction
Smooth muscle (internal) and skeletal muscle (external) sphincters
Main functional sphincter is pubo-rectalis sling of levator ani
Nerves: rectum - visceral; anal canal - somatic
Describe the venous drainage of the rectum and anal canal and explain the
None of the above
X Mark = -6 (conf=3 )
Best Option: Obturator artery
The best answer is obturator artery. The pelvic organs are supplied by named branches
of the internal iliac, not by the internal iliac artery itself. The obturator and iliolumbar
arteries are such branches (note that they do not supply viscera).
•
•
•
•
Right-angle bend back at recto-anal junction
Smooth muscle (internal) and skeletal muscle (external) sphincters
Main functional sphincter is pubo-rectalis sling of levator ani
Nerves: rectum - visceral; anal canal - somatic
Describe the venous drainage of the rectum and anal canal and explain the
occurrence of piles.
Pasted from <https://www.ucl.ac.uk/lapt/laptlite/sys/run.htm?icl08_pelvis_abdom?f=clear?i=icl1?k=1?u=_st1511?i=Imperial >
Arterial Supply of Pelvic Organs
• The rectal venous plexus surrounds the rectum and communicates with the vesical
venous plexus in the male, and the uterovaginal plexus in the female.
• A free communication between the portal and systemic venous systems is established
through the haemorrhoidal plexus.
ant
Internal iliac artery
has anterior and
posterior divisions
The Internal Iliac Artery supplies all the pelvic organs
(except the ovaries), the pelvic walls and much of the
End
buttock (gluteal) region
28/29
Venous Supply of Pelvic Organs
• The Rectal venous plexus consists of two parts, an internal in the submucosa and an
external outside the muscular coat.
Internal plexus
• The internal plexus presents a series of dilated pouches which are arranged in a circle
around the tube, immediately above the anal orifice, and are connected by transverse
branches.
• This internal plexus is also known in some medical communities as the Irving plexus.
External plexus
• The lower part of the external plexus is drained by the inferior rectal veins into the
internal pudendal vein
• The middle part of the external plexus is drained by the middle rectal vein which joins the
internal iliac vein.
• The upper part of the external plexus is drained by the superior rectal vein which forms
the commencement of the inferior mesenteric vein, a tributary of the portal vein.
Haemorrhoids
• The inferior part of the rectal plexus around the anal canal has two parts, an internal and
an external.
• The internal rectal plexus is in connective tissue between the internal anal sphincter and
the epithelium lining the canal.
• This plexus connects superiorly with longitudinally arranged branches of the superior
rectal vein that lie one in each anal column.
• When enlarged, these branches form internal hemorrhoids, which originate above the
pectinate line and are covered by colonic mucosa.
• The external rectal plexus circles the external anal sphincter and is subcutaneous.
Enlargement of vessels in the external rectal plexus results in external hemorrhoids.
Stuart's Anatomy of the Abdomen and Pelvis Page 26
Male Pelvis
29 May 2012
08:48
Identify the component bones of the pelvis and the following landmarks: iliac
crest, anterior superior iliac spine, anterior inferior iliac spine, pubic
symphysis, pubic tubercle, superior and inferior pubic rami, obturator
foramen, ischial tuberosity, ischial spine.
Distinguish structurally and functionally between the pelvis and the
perineum.
Explain the relationships of the urethra, urethral sphincter and erectile tissue
masses in the female and the male perineum.
Identify the component bones of the pelvis and the following landmarks: iliac
crest, anterior superior iliac spine, anterior inferior iliac spine, pubic symphysis,
pubic tubercle, superior and inferior pubic rami, obturator foramen, ischial
tuberosity, ischial spine.
Male & Female Pelves
X = dist. between symphysis pubis
to ant margin of acetabulum
Y = diameter of acetabulum
x
Demonstrate the positions and explain the functions of the ductus deferens,
seminal vesicles and the prostate gland.
Explain the relationships of the urethra, urethral sphincter and erectile tissue
masses in the female and the male perineum.
Explain the anatomical considerations involved in passing a urinary catheter
in a male.
Preprostatic part
• The preprostatic part of the urethra is about 1 cm long, extends from the base of the
bladder to the prostate, and is associated with a circular cuff of smooth muscle fibres (the
internal urethral sphincter).
• Contraction of this sphincter prevents retrograde movement of semen into the bladder
during ejaculation.
Prostatic part
• The prostatic part of the urethra is 3–4 cm long and is surrounded by the prostate. In this
region, the lumen of the urethra is marked by a longitudinal midline fold of mucosa (the
urethral crest). The depression on each side of the crest is the prostatic sinus; the ducts of
the prostate empty into these two sinuses.
• Midway along its length, the urethral crest is enlarged to form a somewhat circular
elevation (the seminal colliculus). In men, the seminal colliculus is used to determine the
position of the prostate gland during transurethral transection of the prostate.
• A small blind-ended pouch—the prostatic utricle (thought to be the homologue of the
uterus in women)—opens onto the centre of the seminal colliculus.
• On each side of the prostatic utricle is the opening of the ejaculatory duct of the male
reproductive system. Therefore the connection between the urinary and reproductive
tracts in men occurs in the prostatic part of the urethra.
Membranous part
• The membranous part of the urethra is narrow and passes through the deep perineal
pouch. During its transit through this pouch, the urethra, in both men and women, is
surrounded by skeletal muscle of the external urethral sphincter.
Spongy urethra
• The spongy urethra is surrounded by erectile tissue (the corpus spongiosum) of the penis.
It is enlarged to form a bulb at the base of the penis and again at the end of the penis to
form the navicular fossa. The two bulbourethral glands in the deep perineal pouch are
part of the male reproductive system and open into the bulb of the spongy urethra. The
external urethral orifice is the sagittal slit at the end of the penis.
• Narrowest part is the external urethral orifice- if a catheter can get through this it should
go all the way to the bladder.
• Weakest part of the urethra is the membranous part of the urethra.
x
y
y
Female Pelvis (singular)
Male Pelvis
Pelvic inlet
Oval/round
Narrow/heart shaped
Sub pubic angle
Wide > 80 degrees
Narrow 50 -60 degrees
Ischial spines
Not projecting medially
Project medially
Greater (false) pelvis
Shallow
Deep
Lesser (true) pelvis
Wide, shallow & cylindrical
Narrow, deep & tapering
Y:X ratio (acetabulum)
Less than one
1 or > 1
• Main function of female pelvis is for childbirth.
Orientation of the Pelvic Girdle
Male & Female
Male Urethra
• In men, the urethra is long, about 20 cm, and bends twice along its course.
• Beginning at the base of the bladder and passing inferiorly through the prostate, it passes
through the deep perineal pouch and perineal membrane and immediately enters the
root of the penis.
• As the urethra exits the deep perineal pouch, it bends forward to course anteriorly in the
root of the penis. When the penis is flaccid, the urethra makes another bend, this time
inferiorly, when passing from the root to the body of the penis. During erection, the bend
between the root and body of the penis disappears.
• The urethra in men is divided into preprostatic, prostatic, membranous, and spongy parts.
Superior pubic ramus
Male
Female
Explain the anatomical considerations involved in passing a urinary catheter
in a male.
Explain the contributions of the internal iliac and the gonadal arteries to the
supply of the pelvic organs and walls.
(plural)
Self-study slide
Learning Objectives
In the anatomical
position: ASIS and
pubic tubercles are in
the same plane
ASIS
Greater and lesser
pelves are continuous
Orientation of the axes
of the abdominal &
pelvic cavities (last lecture)
Pelvic inlet
Pubic
tubercle
• Parietal peritoneum continues into pelvic cavity but does not reach the pelvic floor.
• Pelvic viscera (except ovaries and uterine tubes) are not completely covered by
peritoneum.
• Several folds and pouches are formed.
• Space between pelvic wall and peritoneum not occupied by viscera contain pelvic fascia.
• Pelvic fascial condensations form "ligaments" supporting viscera like cervix, vagina,
prostrate.
Demonstrate the positions and explain the functions of the ductus deferens,
seminal vesicles and the prostate gland.
Contents of male pelvic cavity
•
•
•
•
Ureter, bladder, urethra
Prostrate, ductus deferens, seminal vesicles, bulbourethral glands.
Rectum
Some of the abdominal GI tract spills into the greater pelvis- Caecum, appendix, parts of
sigmoid colon and ileum.
• Vessel, nerves and lymphatics.
Ureter (25 cm)
Parietal
Peritoneum –cut edge
Ampulla of
ductus deferens
Ductus deferens
Ejaculatory duct
Seminal vesicle not shown
Distinguish structurally and functionally between the pelvis and the perineum.
Urethra
20 cm long
1
2
Prostate gland
Perineum
Testis
• The perineum is a diamond-shaped area between the pubic symphysis, ischial tuberosities
and coccyx.
Stuart's Anatomy of the Abdomen and Pelvis Page 27
Sagittal section
Organs from several systems are packed in a small space. GI, urinary,
reproductive, Nerves, vessels and lymphatics. Note the pelvis/perineum
boundary. 1 & 2 indicates normal curvatures in male urethra
Ejaculatory duct
Seminal vesicle not shown
Urethra
20 cm long
Distinguish structurally and functionally between the pelvis and the perineum.
1
2
Prostate gland
Perineum
Testis
• The perineum is a diamond-shaped area between the pubic symphysis, ischial tuberosities
and coccyx.
• Divided into anterior (urogenital) and posterior (anal) triangles.
Pubic Symphysis
Sagittal section
Organs from several systems are packed in a small space. GI, urinary,
reproductive, Nerves, vessels and lymphatics. Note the pelvis/perineum
boundary. 1 & 2 indicates normal curvatures in male urethra
• Prostate gland surrounds 1st (prostatic) parts of urethra
• Ductus deferens from testis passes through inguinal canal, then over, and behind ureter to
enter urethra through the prostate.
• Seminal vesicles on back of bladder-open into ductus deferens between ampulla and
ejaculatory duct.
Ischial Tuberosity
Male: Bladder and Prostate
Coccyx
Bony landmarks from the
inferior aspect of the pelvis
Prostate & urethra
• Posterior compartment: there is the ischio-anal fossae- fat-filled spaces separating anal
canal and levator ani from pelvic walls.
• Anterior triangle divided into superficial and deep parts (or pouches) by the perineal
membrane.
Bulbourethral gland
Corpus cavernosum
Coronal section
– anterior view
Root of penis
The male bladder ‘sits’ on the prostate, which is transfixed by the
first (prostatic) part of the urethra. A urinary catheter, must
negotiate a 900 bend in the urethra as it passes from the perineum
to the pelvis.
Prostate & Seminal Vesicle
Ureter
Bladder
Ductus deferens
and ampulla
• Structure within the anal triangle are the same in both sexes.
Seminal vesicle
• Urine can collect in the superficial pouch if damage occurs from trauma.
Superficial Perineal Structures of Male
Ejaculatory duct
Prostatic urethra
Body of penis
Crus of penis
Glans of penis
Posterior view
Perineal membrane
Ischiopubic ramus
The ductus deferens, seminal vesicles & prostate empty
into the prostatic urethra to form the semen
• Ductus deferens run anterior to the ureter.
• There are 2 seminal vesicles which secrete fluid.
• Prostate gland has many ducts.
Bulb of penis
Levator ani (pelvic floor)
muscles not shown
Perineal membrane fills the urogenital triangle. The
erectile tissues and associated skeletal muscles are
anchored to this.
• Ischial cavernosus is a muscle.
• Bulbospongiousus is a muscle covering the body of the penis.
Prostatic Urethra
where urinary & reproductive tracts meet
Internal urethral sphincter
(smooth muscle)
Internal urethral
sphincter:
Prostatic utricle
(a cul-de-sac)
Smooth muscle, well
organized in males
(not in females)
Deep Perineal Structures of Male
Closed during
ejaculation by
sympathetic stimulus.
(Parasympathetic
stimulation relaxes
the sphincter)
Openings of
ejaculatory
ducts
(Skeletal muscle)
Bulbourethral glands
and ducts.
Ducts open into the
urethra below the
perineal membrane
External urethral sphincter
(skeletal muscle)
The tip of a urethral catheter can also become lodged in
the prostatic utricle
•
•
•
•
Stuart's Anatomy of the Abdomen and Pelvis Page 28
Posterior wall
Small openings are for prostatic gland.
Internal sphincter= smooth muscle
External sphincter= skeletal muscle.
During ejaculation the internal sphincter is closed- retrograde ejaculation.
Ducts open into the
urethra below the
perineal membrane
•
•
•
•
Small openings are for prostatic gland.
Internal sphincter= smooth muscle
External sphincter= skeletal muscle.
During ejaculation the internal sphincter is closed- retrograde ejaculation.
Male Urethra
Basic arrangement
• Deep transverse perineal muscle help keep pelvic diaphragm intact.
1.5 cm
Anal triangle
2.5 cm
• Superior rectal artery is a branch of IMA and joins with Inferior rectal artery to form a
portal-systemic anastomoses.
Rectum and Anal Canal
2 cm
15 cm
External urethral orifice (narrowest part)
Yellow arrows indicate areas of narrowing or obstruction
for the navigation of a catheter.
Explain the contributions of the internal iliac and the gonadal arteries to the
supply of the pelvic organs and walls.
Arterial Supply of Male Pelvis
The rectum receives one pair of arteries from the inf. mesenteric
artery and two pairs from the internal iliac artery. The venous
drainage is similar, thus, there is an important portal-systemic
venous anastomosis around the lower rectum and anal canal.
• Perineal membrane is a thick triangular fascial structure attached to pubic arch.
Posteriorly free margin.
• Deep perineal space: is above the PM and below fascia of pelvic diaphragm
• Superficial perineal space: is below PM and perineal fascia (subcutaneous tissue)
• These spaces are potential spaces and they become real only when for e.g. fluid leaks into
them.
to prostate, bladder
& ductus deferens
Superficial Perineal Pouch- Male
to bladder & ductus deferens
to prostate
Testis receives arterial supply from testicular artery
arising form the abdominal aorta. (not from internal iliac
artery)
Pudendal nerve S2-4
Inferior rectal nerve
Male superficial perineum. The pudendal nerve (S2-S4)
provides all sensory and motor innervation.
•
•
•
•
•
Median erectile tissue mass (corpus spongiosum)- bulb of penis
In females it divides round the vestibule to form vestibular bulbs
Lateral erectile tissue masses (corpora cavernosae) attached to ischiopubic rami
These meet to form shaft and head of penis or clitoris.
Erectile tissue within perineum surrounded by skeletal muscles.
•
•
•
•
•
External iliac goes to the lower limb.
Internal iliac supplies the pelvic organs
Anterior division supplies organs
Posterior division supplies gluteal muscles.
Pudendal supplies perineum and external genitalia.
• In a healthy man you can feel via a rectal examination the prostate gland.
• Enlarged prostate- unable to pass urine easily due to compression of urethra. They also
may need to urinate frequently due to enlarging and pressing on bladder which triggers
urination.
Penis Structure
Corpus cavernosum x 1
v
Superficial Perineal Pouch- Male
Glans – part
of corpus
spongiosum
Corpus
spongiosum
x1
v
• MEAT IS MURDER!!!! grim
Bulb of penis dissected to show erectile tissue columns
and entry of urethra from the deep perineum
Stuart's Anatomy of the Abdomen and Pelvis Page 29
Erectile Tissue in Male
Corpus cavernosum
The crura (legs) of
the corpora
cavernosae attach
• MEAT IS MURDER!!!! grim
Erectile Tissue in Male
Bulb of penis dissected to show erectile tissue columns
and entry of urethra from the deep perineum
• Corpus cavernosum can be filled with blood- main artery is the pudendal artery supplying
them.
Corpus cavernosum
Corpus spongiosum
Male reproductive Tract
root
ureter
Lateral view
Right crus
Membranous
urethra
Vas deferens
root
The urethra
traverses the length
of the corpus
spongiosum.
Catheters can get
caught in the
navicular fossa.
Deep inguinal ring
Ampulla of vas deferens
Seminal vesicles
Superficial inguinal ring
Ejaculatory ducts
Spermatic cord
Prostate gland
• PUDENDAL FTW!!!
Bulbourethral glands
Vas deferens
Explain the contributions of the internal iliac and the gonadal arteries to the
supply of the pelvic organs and walls.
Perineal membrane
Start here
The crura (legs) of
the corpora
cavernosae attach
to the ischiopubic
rami.
Testis in scrotum
Urethra
Glans
Blood Supply of Penis
• Ureter and vas deferens can cross over.
Main blood supply:
Testis and Associated Structures
Longitudinal
section
Internal pudendal artery from
internal iliac
Deep artery – supplies corpora
cavernosa
Self-study slide
Dorsal artery – supplies the skin
and connective tissue
5
Artery of bulb – bulb, corpus
spongiosum, glans and urethra.
4
Spermatozoa
produced here
1
3
Branches supplying the cavernous
spaces are usually coiled – helicine
arteries
2
Parasympathetic stimulation
causes helicine arteries to relax
allowing blood flow
4
Spermatozoa stored
here until ejaculation
31/43
• Tunica albuginea small space- hernia?
What is the blood supply of the
testis?
•
•
•
•
Nerves of the pelvis
Pelvic contents supplied by autonomic nerves only.
Sympathetic from lower thoracic and upper lumbar (T10-L2) segments via hypogastric plexus
Parasympathetic from S2-S4
Pelvic sensation is visceral and poorly localised- pain referred to suprapubic region and
perineum.
Nerves of Pelvis
Erection, Emission and Ejaculation
Neuro-vascular mechanisms
Erection
• Central parasympathetic pathway activated by psychic stimulation. Pudenal
artery/arterioles relax and allow blood flow into cavernous spaces of erectile
tissue (male and female)
Secretion
Pudendal nerve
S2-S4
• Stimulation of para-sympathetic ganglie on prostate, seminal vesicle, and
other glands (in females)
Right & left inferior
hypogastric plexus
Emission
• Central sympathetic pathway activated and smooth muscle contraction of
vasdeferens, prostate, seminal vesicles.
• Internal urethral sphincter (male) contracts. Bladder muscle contraction is
prevented by sympathetic inhibitory action (no urine flow)
Ejaculation
• Entry of semen into urethra triggers somatic reflex (via pudendal nerve)
causing contraction of bulbospongiosus muscle (skeletal)
Detumescence
• Selected sympathetic nerves supplying pudendal arterioles are activated
causing arteriolar constriction to restrict blood supply to cavernous spaces.
Pelvic sympathetic trunk
Pelvic and perineal nerves: Pelvic sympathetic – T10 - L2 via
hypogastric plexus; Pelvic parasympathetic – sacral outflow
from S2-S4; Perineum (somatic): – Pudendal nerve S2-S4
•
•
•
•
Nerves of perineum
Somatic nerves, mainly from sacral segments
Most important nerve is pudendal (S2-4)
Supplies all perineal skeleteal muscles
Sensory to penis, lower urethra, lower rectum and anal canal.
Lumbosacral Plexus
Somatic nerves
leave the pelvis
from the
lumbosacral plexus:
Stuart's Anatomy of the Abdomen and Pelvis Page 30
The main supply to
the perineum is
Lumbosacral Plexus
Somatic nerves
leave the pelvis
from the
lumbosacral plexus:
The main supply to
the perineum is
from the pudendal
nerve S2-S4
‘Pudendal’ derives
from Latin pudere –
to be ashamed
Pudendal Nerve
Important somatic nerve
of perineum
Pudendal nerve in the pudendal
canal in fascia of obturator
internus
The pudendal nerve
passes briefly from pelvis
to buttock, thus passing
behind the fibrous
posterior edge of Levator
ani (the sacrospinous
ligament).
Inferior rectal N
(anal sphincter,
levator ani m.)
Levator ani
Perineal N
dorsal nerve of
Penis (or clitoris)
Motor brs to perineal muscles
Post. Scrotal nerve
(or labia)
Stuart's Anatomy of the Abdomen and Pelvis Page 31
It passes forward below
Levator ani, first in the
lateral wall of the
ischioanal fossa
(posterior perineum) then
branching to anterior
perineum, penis/clitoris
and scrotum/vulva.
Female Pelvis
29 May 2012
10:03
Describe the arrangement of the cervical ligaments and explain their
importance.
Female Pelvic Organs
Explain the structure, functions and clinical significance of the cervix and
sketch its relationship to the vagina.
Use simple sketches to explain the relationships of the labia majora, labia
minora, vestibule, clitoris and urethral orifice.
•
•
•
•
•
•
•
Ovary, uterine (fallopian) tubes.
Uterus and cervix
Vagina
Ureter, bladder, urethra
Rectum
Caecum, appendix, parts of sigmoid colon and ileum
Vessels, nerves and lymphatics
Describe what can be felt in a normal rectal examination in both sexes.
Female Pelvic Organs: Overview
Stability of the Cervix and Vagina
Ureter
Ovary (o) &
uterine tube (UT)
3 sets of fibrous bands – the cervical ligaments – anchor the
cervix in position within the pelvis. These prevent the uterus
from prolapsing through the vagina.
Uterosacral
ligament
Transverse cervical
(cardinal) ligament
Uterus & cervix (C)
Urethra
4 cm long
Sagittal section
Cervix
Pubocervical
ligament
• Cervix can herniate through vaginal wall after multiple childbirths.
• Ligaments stabilise uterus.
• Cardinal is most important.
Uterus and Uterine tube
• Consists of fundus, body, lower segment and cervix
• Uterine tubes consist of infundibulum, ampulla, isthmus and uterine parts.
• Potential communication between peritoneal cavity and exterior via the reproductive passageabdominal ostium of uterine tube and vaginal opening. (None exists in males)
Vagina
10 cm long
Internal anal sphincter
Organs from several systems in the pelvic cavity. No sharing of
reproductive and urinary passages in female.
Female Peritoneum and Pelvic Fascia
• Parietal peritoneum continues into pelvic cavity but does not reach the pelvic floor.
• Uterine tubes are completely enveloped by peritoneum- the broad ligament.
• Ovaries: suspended by mesovarium from posterior of broad ligament (not fully
enveloped)
• Pelvic fascial condensations form "ligaments" supporting viscera e.g. cervix, vagina,
(prostate in males)
• Important pouches in the female pelvis which can be palpated from the outside.
• Ovaries are enveloped on one side or else eggs couldn't get released.
Describe the arrangement of the cervical ligaments and explain their importance.
Broad Ligament, Uterus, Uterine Tubes
& Ovary
Ovarian vessels
Uterus, Uterine Tubes
Ureter
Peritoneal
covering
Suspensory
ligament of ovary
(Embryonic
vestiges)
Broad ligament
Eye of sauron
Round ligament
Recto
uterine pouch
Uterus: Red circles & lines
Vesico-uterine pouch
Uterine Tube: Blue circles
& lines
•The broad
ligaments are
transverse
mesenteries
joining the
uterus to the
pelvic walls.
• Their
important
contents are the
uterine tubes
and uterine
arteries.
• The ovary is suspended by the suspensory ligament of ovary.
• Ovary is the weird acorn looking thing.
• Recto uterine pouch- pouch of Douglas- some uterine vessels can be palpated.
Posterior view
• Fimbriae grab the egg and bring it into the uterus.
• Ectopic pregnancy is very rare but means that the egg is fertilised in the uterine tube.
Explain the structure, functions and clinical significance of the cervix and sketch its
relationship to the vagina.
• Fibro-muscular 'cylinder' with internal and external os.
• Cervical canal lined by mucus secreting simple columnar epithelium. Vaginal surface (of cervix)
Broad Ligament, Uterus, Uterine Tubes
& Ovary (another view)
Round ligament of uterus
Remnant of gubernaculum to inguinal canal
covered in stratified squamous epithelium (cervical smear test)
• Projects into anterior vaginal wall at right angle to vaginal axis.
• Held in position by strong cervical ligaments attached to pelvis and sacrum- part of pelvic fascia.
Inferior pole
of ovary
Uterus – Cervix- Vagina
Stuart's Anatomy of the Abdomen and Pelvis Page 32
The cervical
canal enters the
vagina through
the upper part of
its anterior wall,
Ligament of ovary
Rem of gubernaculum
Posterior view
Suspensory
ligament
of ovary.
For vessels.
Broad ligament
of uterus
peritoneum
Inferior pole
of ovary
Uterus – Cervix- Vagina
The cervical
canal enters the
vagina through
the upper part of
its anterior wall,
the two tubes
forming an angle
of around 900
Ligament of ovary
Rem of gubernaculum
Suspensory
ligament
of ovary.
For vessels.
Broad ligament
of uterus
peritoneum
Posterior view
•
•
•
•
•
Peritoneum covers anterior and posterior surface of uterus.
External os of uterus opens into cervix
Fimbriae are finger like projections guard the osteum of the uterine tube.
One uterine tube opens into the peritoneal cavity.
Ligament of ovary is part of the round ligament.
Body is antiflexed on the
cervix
Cervix is anteverted on
the vagina
Anterior
• Angle of anteversion of the uterus is between cervix and vagina
• Angle of anteflexion is between uterine body and cervix.
• Walls of pelvis supplied by sacral, gluteal and obturator branches.
• Pudendal artery supplies perineum and recto-anal region (via inferior rectal branch)
Cervix- Vagina
Posterior
fornix
Anterior wall
Of vagina
Vaginal
vault
Vaginal canal
Perineal membrane
Female Pelvis: Internal Iliac Artery
Anterior division of
internal iliac a
• Fibromuscular
canal – 7 -9 cm
• Vaginal fornices
at upper end
• Posterior fornix
is important
clinically
• Urethra fused
with the anterior
wall
• There are four fornices- the posterior and two lateral fornices are clinically important.
• The bladder is very closely associated with the vaginal canal.
•
•
•
•
•
•
Arterial Supply of Female Pelvis: Internal Iliac Artery
• Main branches to pelvic viscera are
a. Superior vesical
b. Uterine
c. Middle rectal
Structures Palpable through the Vaginal Wall
Cervix
Ischial spine
Sacral promontory
Uterine artery pulse (lateral fornix)
Ovary
Some of these can be felt through rectal examination.
Posterior division of
internal iliac a
Vaginal
artery is
equivalent
to inferior
vesical a in
men
The Uterine Artery
• Main blood supply to uterus. Enlarges during pregnancy.
• Runs medially towards cervix
• Crosses urreter about 1cm from cervix.
• Uterine branch runs close to uterus in broad ligament.
• Ascending branch supplies uterine tubes and ovary. (Ovary has ovarian artery from
abdominal aorta.)
• Descending branch supplies vagina.
• Uterine artery runs anterior to the ureter
The Uterine Artery & Ovary
Female Perineum
The ovaries lie close to
the openings of the
uterine tubes into the
peritoneal cavity.
Inferior view
Ascending
branch
Descending
branch
Uterine artery
The ovary is on the
posterior surface of broad
ligament facing into the
peritoneal cavity into which
eggs are first released
Ovaries and adjacent
tubes receive an
ovarian artery from the
upper abdominal aorta.
Ureters can be tied off
accidentally with uterine
arteries during
hysterectomy – a classic
disaster.
Female perineum in lithotomy position
Superficial Perineal Structures of Female
Glans of clitoris
from corpus spongiosum
Body of clitoris
from corpus cavernosum
Covering the crus of clitoris
Bulb of vestibule
Female Urethra & Vagina
Basic arrangement
crus of clitoris
Anterior
4 cm
(= prostrate gland in male)
Stuart's Anatomy of the Abdomen and Pelvis Page 33
Levator ani (pelvic floor)
(Paraurethral gland in male )
Glans of clitoris
from corpus spongiosum
Body of clitoris
from corpus cavernosum
Covering the crus of clitoris
Basic arrangement
crus of clitoris
Bulb of vestibule
4 cm
Anterior
(= prostrate gland in male)
Levator ani (pelvic floor)
muscles not shown
(Paraurethral gland in male )
Perineal body
10 cm
As in the male, the perineal membrane fills the
urogenital triangle. The erectile tissues and
associated skeletal muscles are anchored to this.
• This is similar to a male in that you have a bulb covered by the bulbospongiosus muscle.
Underneath ischiocavernosus muscle you have the crus of the clitoris.
Deep Perineal Structures of Female
• Females get more urinary infection because their urethra is shorter.
Nerves of Pelvis
• Pelvic contents supplied by autonomic nerves only.
• Sympathetic from lower thoracic and upper lumbar segments via hypogastric plexus
• Parasympathetic from S2-4 Outflow
• Pelvic sensation is visceral and poorly localised, instead pain is referred to suprapubic regionand
perineum.
Nerves of Pelvis
Anal triangle
These structures
are not present in
the male
Pudendal nerve
S2-S4
Right & left inferior
hypogastric plexus
Perineal Spaces (or pouches)
• Perineal membrane- Thick triangular fascial structure attached to pubic arch. Posteriorly
there is a free margin and anteriorly there is a small gap.
• Deep perineal space is above the PM and below the fascia of the pelvic diaphragm.
• Superficial perineal space is below the PM and perineal fascia (subcutaneous tissue)
• These spaces are potential spaces and they become real only when for example fluid
leaks into them.
Superficial Perineal Pouch- Contents
• Median erectile tissue masses (corpus spongiosum). In females it divides round
vestibule to form vestibular bulbs. The glans of clitoris is derived from this.
• Lateral erectile tissue masses (corpora cavernosum). Paired cylinders, attached to
ischiopubic rami. The body of clitoris is derived from these.
• Erectile tissue within perineum surrounded by skeletal muscles.
Use simple sketches to explain the relationships of the labia majora, labia
minora, vestibule, clitoris and urethral orifice.
Superficial Perineal Pouch & VulvaFemale
Vestibule
Vestibular bulbs
The posterior part
of the corpus
spongiosum
forms two large
vestibular bulbs
surrounding the
lower vestibule
and vagina.
Perineal
body
Pelvic sympathetic trunk
Pelvic and perineal nerves: Pelvic sympathetic – T10 - L2 via
hypogastric plexus; Pelvic parasympathetic – sacral outflow from
S2-S4; Perineum (somatic!) – Pudendal nerve S2-S4
Nerves of Perineum
Anterior labial N (from ilioinguinal L1)
Perineal br of post
cutaneous N of thigh S1-S3
Pudendal N S2 – S4
Pudendal nerve S2-S4: main somatic nerve of the perineum.
Motor to perineal muscles, anal & urethral sphincters, levator ani,
Sensory to external genitalia (vestibule, labia minora and part of
labia majora, lower vagina, clitoris, lower anal canal,
Lymphatic drainage of Pelvis and Perineum
• Pelvic organs drain mainly to external and internal iliac nodes (around the arteries)
• Ovary and testis drain to para-aortic nodes.
• Perineum (including anal canal) and external genitalia drain to superficial inguinal nodes
(subcutaneous below inguinal ligament)
Lymphatic drainage of Pelvis and Perineum
Describe what can be felt in a normal rectal examination in both sexes.
• A digital rectal examination (DRE) is a straightforward procedure performed by a clinician
and should be undertaken by all physicians at some stage during their training.
• The procedure is performed by placing the gloved and lubricated index finger into the
rectum through the anus. The anal mucosa should be palpated for mass lesions knowing
that a small percentage of colorectal tumors may be directly palpable.
• In the female the posterior wall of the vagina and the cervix can be palpated. In the male
the prostate should be palpated. The central sulcus and left and right lobes are easily felt
and any extraneous nodules or masses will be easily detected.
Stuart's Anatomy of the Abdomen and Pelvis Page 34
Pelvic lymph drainage and nodes follow the arteries
rectum through the anus. The anal mucosa should be palpated for mass lesions knowing
that a small percentage of colorectal tumors may be directly palpable.
• In the female the posterior wall of the vagina and the cervix can be palpated. In the male
the prostate should be palpated. The central sulcus and left and right lobes are easily felt
and any extraneous nodules or masses will be easily detected.
• In many instances the digital rectal examination may be followed by proctoscopy or
colonoscopy.
• An ultrasound probe may be placed into the rectum to assess the gynaecological structures
in females and the prostate in the male before performing a prostatic biopsy.
Pelvic lymph drainage and nodes follow the arteries
Perineal lymph drainage is to superficial inguinal nodes
Stuart's Anatomy of the Abdomen and Pelvis Page 35