Download Anatomy Block 5 Oral Quiz Review

Anatomy Block 5 Oral Quiz Review
3/3/2013 12:08:00 AM
Teach or demonstrate the following:
1.) The four layers of the abdominal fascia
1. Superficial Fascia (Camper’s)=fatty, subcutaneous fascia
2. Membranous fascia (Scarpa’s) = deeper membranous fat
3. Deep Investing Fascia = ‘felt’ fascia that covers the abdominal muscles
4. Endoabdominal Fascia = fascia of the transversalis muscle
Note: arcuate line differences
2.) The four muscles of the abdominal wall
1. Rectus abdominus
a. Paired muscles that run vertically
i. Origin – Pubis
ii. Insertion – Costal cartilages 5-7, xiphoid process
iii. Innervation – (T7-T12) segmental nerves
iv. Action – Flexion of the lumbar spine
2. Transversus abdominus
a. Muscle of the lateral & anterior abdomen
b. Horizontal (transverse) fibers & deepest muscle layer
i. Origins
 Iliac crest
 Inguinal ligament
 Thoracolumbar fascia
 Costal cartilages 7-12
ii. Insertions
 Xiphoid, linea alba
 Pubic crest & pectin pubis via conjoint tendon
iii. Innervation
 Thoracoabdominal nn. (T6-T11)
 Subcostal nerve (T12)
 Iliohypogastric nerve (L1)
 Ilioinguinal nerve (L1)
iv. Action – Compresses abdominal contents
3. External oblique
a. Largest, most superficial abdominal muscle
b. ‘Hands in pockets’ fiber direction
i. Origin – Ribs 5-12
ii. Insertions
 Iliac crest
 Pubic tubercle
 Linea alba
iii. Innervation
 Thoracoabdominal nn. (T7-T11)
 Subcoastal nerve (T12)
iv. Action – contralateral rotation of the torso
4. Internal oblique
a. Rotate your ‘hands in pockets’ 90°
b. Inferior layer to external oblique
i. Origin
 Inguinal ligament
 Iliac crest
 Thoracolumbar fascia
ii. Insertions
 Linea alba
 Pectin pubis (via conjoint tendon)
 Ribs 10-12
iii. Innervation
 Thoracoabdominal nn. (T6-T11)
 Subcostal nerve (T12)
 Iliohypogastric nerve (L1)
 Ilioinguinal nerve (L1)
iv. Action
 Compresses abdomen
 Unilateral contraction will rotate vertebral column
ispilaterally
3.) The organization of the neurovascular bundles in the abdominal
wall and relate these structures to back, flank and anterior
abdominal wall pain.
When considering pain of the lower back, flank, or anterior abdomen, one
should know that the dermatomal map of the anterolateral abdomen is
almost identical to the distribution of peripheral nerves. The spinal levels
T7-T12 do not participate in plexus formation. The exception to this rule is
at the L1 level (iliohypogastric & ilioinguinal). Here, the dermatome has two
peripheral nerves and explains why a swift kick to Sam Sauce’s nuts will also
elicit epigastric pain.
Between the internal oblique and transversus abdominis muscles is a
neurovascular plane, which corresponds with a similar plane in the
intercostal spaces. In both regions, the plane lies between the middle and
deepest layers of muscle. The neurovascular plane of the anterior
abdominal wall contains nerves and arteries supplying anterolateral
abdominal wall. In the anterior part of abdominal wall, nerves and vessels
leave neurovascular plane and lie mostly in subcutaneous tissue (Moore’s
191).
This photo is sort of helpful and sort of hilarious.
4.) Describe the four routes of the venous drainage of the anterior
and posterior abdominal wall
1. Superior epigastric vein & branches of musculophrenic vein
 to the internal thoracic
o to the subclavian
2. Inferior epigastric vein & deep circumflex iliac vein
 to the external iliac vessels
3. Superficial circumflex iliac vein & superficial epigastric vein
 to the femoral vein
4. Posterior intercostal vein of 11th intercostal space & anterior branches of
the subcostal veins
 to the azygos/hemiazygos system
5.) The five umbilical peritoneal folds




The peritoneal folds refer to the five, one unpaired and two paired,
foldings in the anterior peritoneum
(1) Median umbilical fold
o overlies the median umbilical ligament
 extends from bladder’s apex to umbilicus
(2) Medial umbilical folds
o overlie the occluded remains of umbilical arteries
(2) Lateral umbilical folds
o overlie the inferior epigastric vessels
o only fold that’s over a functioning adult structure
o extends from the inguinal ring to the arcuate line
o
6.) The borders of the inguinal canal and its contents; relate these
structures to direct and indirect inguinal hernias and to focal and
diffuse abdominal pain
The inguinal canal passes obliquely through the lower abdominal wall,
extending between the superficial and deep inguinal rings. The borders of
the canal are
 Anterior: aponeurosis of external oblique, fleshy internal oblique

Superior: Medial crus of ext obl., musculoaponeurotic arches of
internal oblique & transverse abdominus, transversalis fascia
 Posterior: Transversalis fascia, conjoint tendon (medial), and deep
inguinal ring (lateral)
 Inferior: Inguinal ligament, lacunar ligament (medial), iliopubic
tract (lateral)
Contents are
 Male
o Spermatic cord
 Vas deferens






Ilioinguinal nerve
Genital branch of genitofemoral nerve
Testicular arteries/veins
 Pampiniform plexus
Lymph vessels
Cremaster muscle
Female
o Round ligament of the uterus
o Ilioinguinal nerve
o Lymph vessels
Direct hernia
 Passes directly through the abdominal wall (Hesselbach’s Δ) to the
superficial inguinal ring, forming peritoneal sac
o Linea semilunaris (lateral rectus border)
o Inferior epigastric vessels
o Inguinal ligament
 Due to muscular weakness or increased intrabdominal pressure
 More common in aging men

Indirect




Does not extend to scrotum
hernia
Traverses the superficial, deep inguinal rings
Is within the covering of spermatic cord
May descend into scrotum
can be congenital, common in younger males
7.) The location of the kidney, adrenal gland, urinary pelvis and
ureter on a human and on an abdominal plain film and relate these
structures to the presentation of flank pain
Along mid-clavicular line
 Left kidney: T12-L3
 Right Kidney: T12.5-L3.5
 Pelvis’: L1-L2
 Adrenals: T11
The ureters emerge ~L2 and descend in parallel (approx. linea semilunaris)
and hit the bladder, which is midline, just superior to the pubis and inguinal
ligaments.
On abdominal plain film:
 P – renal pelvis
 * - ureter
 B – bladder
 Adrenals – unmarked
 K - kidney
Week 32
3/3/2013 12:08:00 AM
1. The distinction between parietal and visceral peritoneum and
explain their sensitivity to pain.
Parietal peritoneum lines the abdominal wall and is external to the visceral
peritoneum, which invests the viscera. The parietal peritoneum is extremely
sensitive to pain and is innervated by the nerves involved with the local
abdominal wall and diaphragm. Any injury or inflammation to the parietal
peritoneum will present as an acute localized pain.
The visceral peritoneum is not so sensitive and mainly carries sympathetic
nerves to their appropriate viscera. However, pain receptors will fire on the
visceral peritoneum if:
 Overdistension of hollow viscera (ie. Colon)
 Traction on the mesenteries which will stretch nerve plexi in the
organ or mesentery
 Smooth muscle spasm
 Ischemia
Injury to the visceral peritoneum presents as a dull, diffuse abdominal pain.
2. The concept of referred pain and to predict where in the body the
pain of specific organ inflammation (dysfunction) will present
clinically.
Referred pain is simply the presentation of pain that reflects an injurious
stimulus elsewhere, usually in the viscera. Note, this is not pain radiation.
Referred pain happens when nerve fibers from regions of high sensory
input (such as the skin) and nerve fibers from regions of normally low
sensory input (such as the internal organs) happen to converge on the same
levels of the spinal cord. The best known example is pain experienced during
a heart attack. Nerves from damaged heart tissue convey pain signals to
spinal cord levels T1-T4 on the left side, which happen to be the same levels
that receive sensation from the left side of the chest and part of the left arm.
A popular theory suggests that because the brain isn't used to receiving such
strong signals from the heart, so it interprets them as pain in the chest and
left arm.
Following the concept of spinal levels illustrated above, think about shoulder
pain. C3-C4-C5  keeps you alive right? The phrenic nerve is responsible
for relaying any injury or inflammation of the thoracic diaphragm and shares
spinal roots with the supraclavicular nerves (C3, C4), thus, diaphragmatic
irritation may present as shoulder pain.
Because I don’t have a great understanding of the innervation of the
abdominal organs yet, I’m going to let this image from Moore’s pick up the
slack.
3. Trace or follow the surfaces of the parietal and visceral
peritoneum and their various interconnecting ligaments
throughout the peritoneal cavity and predict to drainage locations
for excessive fluids (ascites) in the supine patient.
As detailed above, the parietal peritoneum lines the abdominal cavity. The
visceral peritoneum invests the abdominal viscera and whose invaginations
develop into peritoneal ligaments that hold the viscera in place and whose
double-layered structures allows the passaging of neurovasculature to the
appropriate organ. Continuities and connections between the parietal and
visceral peritoneum exists where the gut tube exits and enters the
abdominal cavity.
Mesentery is a term for a double layer of peritoneum, both parietal and
visceral. Usually connecting an organ to the abdominal wall. Anything with
‘meso-‘  mesentery. Note there is a mesoesophagus, mesogastrium &
mesoappendix, aside from the mesocolons. See omentums in #4, similar
structures.
Peritoneal ligaments are double layered (visceral?) peritoneum that
connects organs to each other, or to the abdominal wall. They are named,
typically, after what they connect.
The liver is connected by the:
 Falciform ligament – to the anterior abdominal wall
 Coronary ligament (3 parts) connect to inferior diaphragmatic
surface
o Right triangular
o Left triangular (continuous with falciform)
o Hepatorenal ligament – from lower posterior liver to the right
kidney, forms right margin of the epiploic foramen
 Hepatogastric ligament – to the membranous portion of the lesser
omentum
 Hepatoduodenal ligament – to the duodenum via the free,
thickened edge of the lesser omentum
The stomach is connected by the:
 Gastrophrenic ligament – to the inferior diaphragmatic surface
 Gastrosplenic ligament – to the splenic hilum
 Gastrocolic ligament – to the transverse colon via the greater
omentum, saggy gross part
The spleen is connected by the:


Others


Gastrosplenic ligament (above)
Splenorenal ligament – to the left kidney
Phrenicocolic ligament
o Left hepatic flexure of transverse colon to the diaphragm
Phrenicoesophageal ligament
o Distal esophagus to the inferior diaphragm
Ascites: would collect in hepatorenal and rectouterine recesses in the
supine patient.
4. The distinction between greater and lesser omental sac and
between the greater and lesser omentum
The greater omental sac is synonymous with the general abdominal cavity.
This includes everything inside the peritoneum, except the lesser sac.
The lesser omental sac is formed by the greater and lesser omentum(s). It
is connected with the greater sac at one point, known as the Foramen of
Winslow or the epiploic foramen, which is generally proximal to the stomach.
The margins of the sac are:
 Anteriorly by quadrate lobe of liver
 Left lateral margin by left kidney/adrenal
 Right lateral margin by epiploic foramen & lesser omentum
 Behind the stomach, front of pancreas
The greater omentum is a large 4-layered fold of visceral peritoneum that
hangs inferiorly from the greater curvature of the stomach, passing over the
small intestines, before it reflects upon itself and ascends to the transverse
colon before reaching the posterior abdominal wall.
The lesser omentum is a double layer of visceral peritoneum that extends
from the liver to the lesser curvature of the stomach and the origin of the
duodenum.
5. Delineate the location of the esophagus, stomach, and duodenum
and describe their surrounding relationships with the structures
of the peritoneal cavity and the posterior body wall
The esophagus is about 27cm long and runs from the pharynx to the cardia
of the stomach.
 Posterior  posterior abdominal wall, thoracic duct at T5, and
descending aorta.
 Anterior  trachea until T4/5, left bronchus, left atrium, and
diaphragm

Left lateral  thoracic duct, aorta, left subclavian artery and left
lung
 Right lateral  right lung, azygos vein (better approach side for
esophageal surgery)
The stomach
 Posterior  Lesser sac,
pancreas, transverse
mesocolon, transverse colon,
left kidney/adrenal, spleen &
splenic artery
 Anterior  Anterior abdominal
wall, left costal margin,
diaphragm, & left lobe of liver
 Superior  Left dome of
diaphragm
The duodenum is about 25cm long and
has four regions (see dotted line on image below)
a. First (5cm)
 Anterior  liver & gallbladder, peritoneum
 Posterior  Bile duct, gastroduodenal artery, portal vein, IVC
 Superior  Epiploic foramen, neck of gallbladder
 Inferior  Pancreas
 Medial  pylorus
b. Second (8cm) descending
 Anterior  gallbladder, hepatic flexure
 Posterior  right kidney/hilum, psoas major
Medial  pancreas, pancreatic duct
Superior  Superior duodenum
Inferior  inferior duodenum
Laterial  Ascending colon
(10cm)
Anterior  small bowel mesentery,
superior mesenteric a/v
 Posterior  right psoas, IVC, aorta
 Superior  head, uncinate process
of pancreas, superior mesenteric




c. Third

vessels
 Inferior  ileum
d. Fourth (2.5cm) ascending
 Anterior  beginning of root of mesentery, jejunum
 Posterior  left psoas, left margin of aorta
 Medial  Superior mesenteric a/v, uncinate of pancreas
 Superior  Body of pancreas
 Inferior  coils of jejunum
6. Trace the blood supply, innervation and lymphatic drainage of the
esophagus, stomach, and duodenum
Esophagus
Arterial blood supply
o Neck: inferior thyroid artery
o Thorax: branches from thoracic aorta
o Abdomen: branches from left gastric artery
Venous drainage
o Neck: inferior thyroid vein  brachiocephalics
o Thorax: Azygos, hemiazygos systems
o Abdomen: left gastric vein  portal vein
Innervation
o Sympathetic: greater splanchnic nerve (T6-T9) & periarterial
plexuses via left gastric and inferior phrenic arteries
o Parasympathetic: Esophageal plexus, (by vagal trunks
forming anterior and posterior gastric branches)
o Enteric
 Myenteric neurons
 Between longitudinal and circular muscle layers
 Submucosal neurons
 Deep to the muscularis mucosae
 Interneurons
 Ascend/descend between the above on vertical
axis
Lymphatic drainage
o Neck: deep cervical lymph nodes to thoracic duct
o Thorax: superior and posterior mediastinal nodes to thoracic
duct
o Abdomen: follows left gastric vein to celiac & gastric nodes to
the intestinal lymphatics trunks to the cisterna chyli
Stomach
Arterial blood supply (celiac trunk)
o Left gastric artery to left aspect of lesser curvature
o From splenic  short gastric & left gastroepiploic
 Usually a pair of short gastric arteries to the fundus
Left gastroepiploic to the left aspect of greater
curvature of stomach
 Anastomosis with right gastroepiploic artery
o From common hepatic artery
  Hepatic artery  right gastric artery to the right
aspect of the lesser curvature
  Gastroduodenal artery  right gastroepiploic artery
to the right aspect of the greater curvature of the
stomach

Venous drainage
o Right & left gastric veins  portal vein
o Right gastroepiploic  superior mesenteric vein  portal
o Left gastroepiploic  splenic  portal
o Short gastric  splenic  portal
Innervation
o Sympathetic: greater splanchnic nerve (T6-T9) via celiac
plexus
o Parasympathetic:
 Anterior vagal trunk: anterior gastric branches
 Posterior vagal trunk: anterior and posterior gastric
branches
o Enteric
 Myenteric neurons
 Between longitudinal and circular muscle layers
 Submucosal neurons
 Deep to the muscularis mucosae
 Interneurons
Ascend/descend between the above on vertical
axis
Lymphatic drainage
o All the following are nodes that drain into the celiac 
intestinal trunks to the cisterna chyli
 Superior gastric nodes
 Inferior gastric nodes
 Pacreaticolienal nodes
 Paracardial nodes


Subpyloric nodes
Duodenum
Arterial blood supply
o Gastroduodenal  superior pancreaticoduodenal artery
Splits anterior/posterior, supplying the anterior aspects
of pancreas & duodenum and the posterior aspects
o The above anastamose with the branches from the inferior
pancreaticoduodenal artery, which at that point, demarcates
the border between the foregut and the midgut, as the IPDA
is a branch off the superior mesenteric artery
Venous drainage
o Posterior and anterior pancreaticoduodenal veins which reach
the portal vein via the superior mesenteric vein & splenic vein
Innervation

o Sympathetic: greater and lesser splanchnic nerves (T5-T11)
via the celiac and superior mesenteric plexuses and via
periarterial plexuses on the pancreaticoduodenal arteries
o Parasympathetic: anterior and posterior vagal trunks
Lymphatic drainage
o Anterior aspects of the duodenum drains to pyloric nodes
o Posterior aspects drain to the superior mesenteric nodes
 Both of the above drain to the celiac nodes
7. Delineate the location of the liver, gall bladder, spleen and
pancreas and describe their surrounding relationships with the
structures of the peritoneal cavity and the posterior body wall
The liver mainly occupies the upper right quadrant, below ribs 6-10, and on
the left 6-7 costal cartilages. It has 4 lobes, 2 major, and major three
surfaces.
 Superior  involves both right & left lobes, convex, which fits under
the vault of the diaphragm, which encompasses that entire surface

Inferior  uneven, multiple concavities, directed inferoposteriorly
o Gastric impression  major fossa formed by the stomach
under the left lobe
o Duodenal impression  just posterior to gallbladder fossa and
anterior to the renal impression
o Renal impression  posterior fossa under the right lobe
o Colic impression  anterior fossa formed by the right colic
flexure
o Gallbladder fossa  formed by ________ (fill-in)
 Posterior  rounded and broad on right lobe, narrow on left
o There is a portion not covered in peritoneum, is directly
attached to the thoracic diaphragm, marked by the coronary
ligaments
o The posterior right lobe and caudate lobe ‘wrap’ a portion of
the IVC
Gall Bladder
 Anterior  anterior abdominal
wall & inferior surface of liver

Posterior  Transverse colon; 1st
& 2nd parts of duodenum
Spleen (left side )
 Superior  diaphragm
 Posterior  left kidney
 Anterior  Stomach
 Inferoanterior  transverse colon
 Medial  lesser sac, pancreas, splenic hilum
Pancreas


Head
o
o
o
Body
o
o
Anterior  transverse colon
Right lateral  duodenum (spooning)
Posterior  IVC, common bile duct, aorta, renal veins,
Anterior  stomach (separated by omental bursa)
Posterior  Abdominal aorta, splenic vein, left kidney and
associated vessels, origin of superior mesenteric artery
o Inferior  duodenojejunal flexure & left colic flexure

Tail
o Extends to the gastric surface of spleen to the phrenicosplenic
ligament and contacts the left colic flexure
8. Trace the blood supply, innervation and lymphatic drainage of the
liver, gall bladder, spleen and pancreas
Liver
Blood supply
o Arterial: from common hepatic  hepatic artery
 Left hepatic artery to the left lobe
 Right hepatic artery to the right lobe
o Portal: from the portal vein, the liver derives nearly 50% of
its oxygen supply
Venous drainage
o The hepatic veins carry de-oxygenated blood from the liver
and blood cleaned by the liver from the portal circulation to
the inferior vena cava
Note: no valves on these veins and the derive from the
‘central vein’ from histology
Innervation (via hepatic plexus, a derivative of the celiac plexus)
o Sympathetic: Greater and lesser splanchnic nerves (T6-T11)
o Parasympathetic: anterior and posterior vagal trunks
Lymphatic drainage
o All lymphatic vessels of the liver lead to the celiac nodes
 Remember these drain to the intestinal lymph trunks to
the cisterna chili

Gall Bladder
Arterial blood supply
o Celiac trunk  right hepatic  cystic artery
 Most common arrangement (~70%)
Venous drainage
o The cystic vein doesn’t have to travel far to dump its blood
into the right branch of portal vein
Innervation (via celiac plexus)
o Sympathetic: greater & lesser splanchnic nerves
o Parasympathetic: anterior and posterior vagal trunks
 Causes contractions (peristalsis) of gall bladder
Lymphatics
o To hepatic lymph nodes that send efferents to the celiac
nodes   cisterna chili
Spleen
Arterial Blood Supply
o Celiac trunk  splenic  splenic hilum
Venous drainage
o Splenic vein joins the superior mesenteric vein to form the
hepatic portal vein
Innervation (via celiac plexus)
o Sympathetic: Greater and lesser splanchnic nerves (T6-T11)
o Parasympathetic: anterior and posterior vagal trunks
Lymphatic drainage
o Into pancreaticosplenic nodes, pyloric nodes, which join the
intestinal trunks to the cisterna chili
Pancreas
Arterial Blood Supply
o From gastroduodenal  superior pancreaticoduodenal artery
 Splits anterior/posterior, supplying the anterior aspects
of pancreas & duodenum and the posterior aspects
o The SPDA anastamoses with the branches from the inferior
pancreaticoduodenal artery, which at that point, demarcates
the border between the foregut and the midgut, as the IPDA
is a branch off the superior mesenteric artery
o From the splenic artery  dorsal artery to pancreas
Venous drainage
o The superior pancreaticoduodenal veins join with the portal
vein
o The inferior pancreaticoduodenal veins join with the jejunal
veins  superior mesenteric  portal
Innervation (celiac and superior mesenteric plexuses)
o Sympathetic: Greater and lesser splanchnic nerves (T6-T11)
o Parasympathetic: anterior and posterior vagal trunks
 Positive secretomotor function
Lymphatic drainage
o Pancreaticoduodenal nodes to the intestinal trunks to the
cisterna chyli
Week 34: Welcome Back
3/3/2013 12:08:00 AM
Demonstrate the blood supply, innervation and lymphatic drainage
of the jejunum and the ilium.
Note: There’s barely any difference between these answers (jejunum &
ilium) other than anatomic location and the arterial characteristics
Jejunum
Arterial blood supply
o Abdominal aorta  Superior mesenteric artery
 jejunal branches
o Branches form loops with each other termed arterial arcades
and send vertical branches (vasa recta) directly to the
intestinal parenchyme
 Jejunal branches have long vasa recta
Venous drainage
o The superior mesenteric vein drains the jejunum (and ilium)
--> becomes portal vein
Innervation (by extension along superior mesenteric vessels)
o Superior mesenteric plexus
Sympathetic: Greater & lesser splanchnic nerves (T8T10)
 Parasympathetic: posterior vagus n. via celiac plexus
o Enteric
 Myenteric neurons
 Between longitudinal and circular muscle layers
 Submucosal neurons
 Deep to the muscularis mucosae
 Interneurons

Ascend/descend between the above on vertical
axis
Lymphatic drainage
o Lacteals, blind-ended lymphatic spaces within intestinal villi,
absorb fat from the lumen and deliver it to three groups of
nodes, in sequential order
 Juxtaintestinal: right next to the intestinal wall
 Mesenteric: scattered among arcades


Superior central: located by the proximal superior
mesenteric artery
Ilium
Arterial Blood Supply
o Abdominal aorta  superior mesenteric artery
 ileal branches
o Branches form loops called arterial arcades and send vertical
vasa recta to the intestinal parenchyme
 Vasa recta are short compared to jejunum
Venous Drainage
o The superior mesenteric vein drains the jejunum (and ilium)
--> becomes portal vein
Innervation
o Superior mesenteric plexus
 Sympathetic: Greater & lesser splanchnic nerves (T8T10)
 Parasympathetic: posterior vagus n. via celiac plexus
o Enteric
 Myenteric neurons
 Between longitudinal and circular muscle layers
 Submucosal neurons
 Deep to the muscularis mucosae
 Interneurons
 Ascend/descend between the above on vertical
axis
Lymphatic Drainage
o Lacteals, blind-ended lymphatic spaces within intestinal villi,
absorb fat from the lumen and deliver it to three groups of
nodes, in sequential order
 Juxtaintestinal: right next to the intestinal wall
 Mesenteric: scattered among arcades
 Superior central: located by the proximal superior
mesenteric artery
Demonstrate the blood supply, innervation and lymphatic drainage
of the ascending, transverse and descending colon and rectum.
Ascending Colon
Arterial Blood Supply
o Abd aorta  SMA  ileocolic artery & right colic artery
o These anastamose with each other AND the middle colic
artery, forming the marginal artery
Venous Drainage
o Ileocolic & right colic veins  Superior mesenteric vein
 portal vein
Innervation
o Sympathetic: lesser splanchnic nerve (T10)
o Parasympathetic: posterior vagus via superior mesenteric
plexus
Lymphatic Drainage
o From paracolic & epicolic lymph nodes  ileocolic &
intermediate right colic nodes  superior mesenteric nodes
Transverse Colon
Arterial Blood Supply
o AA  SMA  middle colic artery, with small contributions
from the right and left colic arteries via marginal anastamoses
Venous Drainage
o Middle colic vein  SMV  portal vein
Innervation (both via superior mesenteric plexus)
o Sympathetic: lesser splanchnic nerve (T11)
o Parasympathetic: posterior vagal trunk
Lymphatic Drainage
o Middle colic lymph nodes  SM nodes
Descending (& Sigmoid)
Arterial Blood Supply
o AA  IMA  left colic and sigmoid arteries
o Marginal artery also contributes via anastamosis
Venous Drainage
o Inferior mesenteric vein  splenic  portal
Innervation
o Sympathetic: lumbar splanchnic nn, superior mesenteric
plexus, and IMA periarterial branches
o Parasympathetic: Pelvic splanchnic nn via the inferior
hypogastric plexus
Lymphatic Drainage
o Epicolic & paracolic nodes  intermediate colic nodes
 inferior mesenteric nodes
Rectum
Arterial Blood Supply
o Superior rectal artery (from IMA)
o Right and left middle rectal arteries (from anterior divisions of
common iliac arteries)
o Inferior rectal artery (from internal pudendal arteries from
internal iliac artery)
 Note: inferior & superior anastamose, tho rarely do they
anastamose with the middle rectals
Venous Drainage
o Via superior, middle and inferior rectal veins
 Note: portal meets systemic via anastomoses
 Hemorrhoids!
Innervation
o Sympathetic: lumbar splanchnic nn., periarterial plexuses of
IMA & superior rectal arteries
o Parasympathetic: pelvic splanchnic nerves (S2-S4) via the left
and right inferior hypogastric plexuses
o Motor: pudendal (S2-S4)  external anal sphincter
o Somatic afferents: inferior anal (rectal) nerve (S2-S4)
Lymphatic Drainage
o Superior ½ rectum: Sacral nodes  pararectal nodes 
inferior mesenteric nodes  caval nodes
o Inferior ½ rectum: sacral nodes  internal iliac nodes
Use embryological events to explain the adult morphology of the
pancreas and use its adult structure to explain the dire
consequences of most pancreatic diseases.
At the septum transversum, one dorsal and one ventral bud form from the
duodenum, each with their own common duct. As the small intestine
develops, the smaller ventral bud, which begins as a branch of the future
common bile duct, connecting the liver and gall bladder to the duodenum,
swings around to the dorsal side. The dorsal bud, which has a direct
connection of its own to the duodenum, remains put. The ventral bud joins
the dorsal around the sixth week.
The ventral duct will give rise to the pancreatic duct and the dorsal duct will
become the accessory pancreatic duct. Usually, this accessory duct joins the
main duct to empty into the common bile duct. However, sometimes the
accessory duct’s opening to the duodenum remains patent and will empty
directly into the duodenum via the minor duodenal papilla.
The adult structure of the pancreas has a single output of pancreatic juice.
Any structural blockage or stricture of drainage vessels is likely to cause
damage because of the specific contents (zymogens) of the pancreatic juice
becoming activated and causing self-digestion. Note that blockage at the
ampulla of Vater, due to gallstone etc…, will also block bile drainage to the
duodenum and will back up into the pancreas, activating digestive juices.
Compare and contrast the flow of bile from the flow of pancreatic
juices through the biliary tree into the duodenum.
Pancreatic juices first begin at the exocrine acinus. There, acinar cells
secrete digestive zymogens into the acinar lumen, which is collected through
a series of intercalated ducts that eventually join the pancreatic duct (or
accessory pancreatic duct.) In those ducts, water and bicarbonate are
secreted in large amounts that add significant volume and dilute the
pancreatic juice. The pancreatic duct joins the common bile duct just
proximal to the ampulla of Vater, and together, perforate the duodenum at
the major duodenal papilla.
Bile begins in the liver. From hepatocyte to the bile canaliculi, the bile flow
from small intrahepatic ducts to extraheptic ducts that join the cystic duct to
form the common bile duct. Note, the biliary duct epithelium also secretes a
large volume of water and bicarbonate to the bile. The common bile duct,
as above, joins the pancreatic duct and, together, they drain their contents
into the descending duodenum at the major duodenal papilla.
Compare and contrast the role of the small bowel in digestion to that
of the large bowel.
The small bowel, from duodenum to ilium, is responsible for the body’s
chemical digestion of protein, fat, and certain carbohydrates. The large
intestine does not produce digestive enzymes and serves mostly an
absorptive and poo-forming function. However, a small amount of digestion
does occur on complex plants starches that remain undigested by our
endogenous amylases, etc. The digestion that does occur is by gut flora
which possess digestive enzymes we do not. The resultant products
(acetate, propionate, butyrate) are absorbed at the large colon as well and
provide a small caloric input daily.
Use vertebral levels to relate the pancreas, duodenum, kidneys and
spleen to each other on an abdominal plain film.
Vertebral levels
Pancreatic Body – L2
Duodenum
 Part 1 – L1
 Part 2 – L2  L3
 Part 3 – L3
 Part 4 – L3/L2
Kidneys – T12  L3
 Right kidney slightly lower than left
Spleen – T7/T8  T11
Week 35
3/3/2013 12:08:00 AM
Demonstrate the blood supply to the organs of the celiac artery
territory
Liver
 Celiac trunk  common hepatic a.  hepatic a.  r & l hepatic aa.
Gall Bladder
 Celiac trunk  common hepatic a.  hepatic a.  r. hepatic a.
 cystic artery
Stomach
 Celiac trunk  left gastric a.  left aspect of lesser curvature

Celiac trunk  common hepatic a.  hepatic a.  right gastric a.
 right aspect of the lesser curvature
 Celiac trunk  splenic a.  left gastro-omental a.
 left aspect of greater curvature
 Celiac trunk  common hepatic a.  gastroduodenal a.
 right gastro-omental a  right aspect of greater curvature
 Celiac trunk  splenic a.  short gastric & posterior gastric aa.
Esophagus
 Celiac trunk  left gastric a.  esophageal branch  abdominal
esophagus
Spleen
 Celiac trunk  splenic a  splenic hilum
Superior duodenum
 Celiac trunk  common hepatic a.  gastroduodenal a.
 superior pancreaticoduodenal a.  anterior and posterior
branches
Superior pancreas
 Celiac trunk  common hepatic a.  gastroduodenal a.
 superior pancreaticoduodenal a.  anterior and posterior
branches
Demonstrate the blood supply to the organs of the superior and
inferior mesenteric artery territories.
Inferior duodenum & pancreas

SMA  inferior pancreaticoduodenal aa.  anterior & posterior
branches
Jejunum & ileum
 SMA  jejunal branches
o Branches form loops with each other termed arterial arcades
and send vertical branches (vasa recta) directly to the
intestinal parenchyme
o Jejunal branches have long vasa recta
 SMA  ileal branches
o Branches form loops called arterial arcades and send vertical
vasa recta to the intestinal parenchyme
o Vasa recta are short compared to jejunum
Cecum & Ascending Colon
 SMA  ileocolic a & right colic a.
Transverse Colon
 SMA  middle colic artery & marginal artery
Descending Colon
 IMA  left colic & marginal artery
Sigmoid Colon
 IMA  sigmoid arteries
Rectum
 Superior: IMA  superior rectal artery
 Middle & inferior from common & internal iliac arteries
Demonstrate the clinical presentation of portal hypertension a) due
to liver failure; b) due to occlusion of the portal vein proximal to the
splenic vein
A) Liver failure will cause portal hypertension that can manifest in multiple,
and usually, in all of the following presentations:
 Esophageal varices (via left gastric vein backup)
 Hemorrhoids (via inferior mesenteric veins)
 Caput medusa (via occluded umbilical veins)
 Ascites
B) Portal occlusion (at juncture of splenic/SMV, before the umbilical and left
gastric veins empty into portal system)


Milder ascites
Hemorrhoids
For next three parts, I give you Jack
Greater splanchnic nerve: T6-T9
Lesser splanchnic nerve: T10-T11
Least splanchnic nerve:
T12
Generally, this is the
schpeal for each of the
next three questions.
At each spinal nerve, you
have visceral and somatic
afferents. With chronic
stimulation of the visceral
components, that impulse
will spill over and
stimulate the somatic
nerve at that spinal level
and cause the sensation of
pain. In the anterior
abdominal wall, we use
four quadrants to navigate
the clinical presentation of
abdominal pain and the
spinal levels of each
quadrant’s underlying
viscera to create a
differential.
Use the innervation of the celiac organs to diagnose upper right or
left quadrant pain patterns
The celiac plexus provides sympathetics from the greater and lesser
splanchnic nerves, which are T6-T11. Note, T11 is a small contribution here.
 LUQ – spleen, pancreas, pancreatic duct, stomach, esophagus
 RUQ – liver, gall bladder, pancreas, pylorus
Use the innervation of the superior mesenteric organs to diagnose
periumbilical pain patterns and lower right quadrant pain patterns
The superior mesenteric organs (midgut) receive visceral input from all three
thoracic splanchnic nerves, which means that T6-T12 are involved here.
 Periumbilical – small bowel mesentery, pancreas, appendix, distal
stomach
 LRQ – appendix, cecum, ascending colon, ileum
Use the innervation of the inferior mesenteric organs to diagnose
lower left quadrant pain patterns
The inferior mesenteric organs receive sympathetic input from the lumbar
splanchnic nerves, which are L1 & L2, via the inferior mesenteric plexus.
Also, parasympathetics now originate from the pelvic splanchnic nerves (S2S4).
 LLQ: Transverse, descending, sigmoid colon, rectum, mesentery