Download File - Shabeer Dawar

ABDOMINAL VISCERA
FOR EACH PART YOU MUST KNOW:
1. SURFACE ANATOMY
2. RELATIONS
3. PERITONEAL COVERING
4. BLOOD SUPPLY
5. NERVE SUPPLY
6. LYMPHATIC DRAINAGE
7. SUPPORT (IN SOME PARTS)
SMALL INTESTINE
• DUODENUM: 10 inch (25cm)fixed part
• JEJUNUM & ILEUM: 20 ft (6m)movable
part (with mesentery)
JEJUNUM & ILEUM
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Length: 6 meters (20 feet)
Beginning: duodenojejunal flexure
Termination: ileocecal junction
Embryological origin: midgut
Peritoneal fold: mesentery of small intestine
Arterial supply: jejunal & ileal branches of
superior mesenteric
• Lymphatic drainage: superior mesenteric
lymph nodes
• Nerve supply: superior mesenteric plexus:
sympathetic & parasympathetic (vagus)
MESENTERY OF SMALL INTESTINE
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1.
2.
3.
4.
5.
Extent: from duodenojejunal flexure to
ileocecal junction
Formation: formed of 2 layers
Free border (6 meters long): encloses
jejunum & ileum
Root (6 inches long, J-shaped): crosses
superficial to the following structures:
Third part of duodenum
Abdominal aorta
Inferior vena cava
Right psoas major
Right ureter
MESENTERY OF SMALL INTESTINE
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1.
2.
3.
4.
5.
Shape: Fan-shaped with undulations
Content of root: superior mesenteric
vessels
Contents (structures between its 2
layers):
Jejunal vessels: form few arcades
Ileal vessels: form many arcades
Mesenteric lymph nodes
Autonomic nerve fibers
Mesenteric fat
MESENTERY OF SMALL INTESTINE
JEJUNUM
1. Length: shorter (proximal 2/5)
2. Diameter: wider
3. Wall: thicker (more numerous plicae
circulares: circular folds of mucosa)
4. Appearance: more red in color (more
vascular)
5. Vessels: less arcades, long terminal
branches
6. Mesenteric fat: small amount near
intestinal border
7. Aggregations of lymphoid tissue: few
ILEUM
1. Length: longer (distal 3/5)
2. Diameter: narrower
3. Wall: thinner (less numerous plicae
circulares: circular folds of mucosa)
4. Appearance: light red in color (less
vascular)
5. Vessels: more arcades, short terminal
branches
6. Mesenteric fat: large amount near
intestinal border
7. Aggregations of lymphoid tissue:
numerous (Peyer’s patches)
LARGE INTESTINE
PARTS:
1. Cecum
2. Appendix
3. Ascending colon
4. Transverse colon
5. Descending colon
6. Sigmoid (pelvic) colon
7. Rectum
8. Anal canal
9. N.B.: Parts of large intestine in
abdomen: from 1 to 5
LARGE INTESTINE
CHARACTERISTICS:
1. Teniae coli: 3 longitudinal muscle
bands
2. Sacculations (haustrations): teniae
coli are shorter than large intestine
3. Appendices epiploicae: short
peritoneal fold filled with fat
• N.B.: characteristics are present in all
large intestine EXCEPT: in rectum &
anal canal
LARGE INTESTINE
• Embryological origin:
1. From midgut: cecum, appendix, ascending
colon, right 2/3 of transverse colon
2. From hindgut: left 1/3 of transverse colon,
descending & sigmoid colon, rectum, upper
half of anal canal
• Peritoneal fold:
1. Appendix, transverse & sigmoid colon:
have mesentery
2. Cecum: completely covered by peritoneum,
but has no mesentery
3. Ascending & descending colon: covered
anteriorly & on the sides
4. Rectum & anal canal: discussed later
LARGE INTESTINE
• Arterial supply:
1. Midgut: colic branches of superior
mesenteric
2. Hindgut: inferior mesenteric
• Lymphatic drainage:
1. Midgut: superior mesenteric lymph nodes
2. Hindgut: inferior mesenteric lymph nodes
• Nerve supply:
1. Superior mesenteric plexus: sympathetic &
parasympathetic (vagus)
2. Inferior mesenteric plexus: sympathetic &
parasympathetic (pelvic splanchnic nerves)
LARGE INTESTINE
SURFACE ANATOMY
APPENDIX
•
Surface anatomy: the base of
appendix is marked by Mc’Burney’s
point: A point at the junction of lateral
1/3 & medial 2/3 of a line traced from
right anterior superior iliac spine to
umbilicus
•
Opening: at posteromedial aspect of
cecum, 1 inch below ileo-cecal
junction
APPENDIX
• Positions: (from
most to least
common)
1. Retrocecal: most
common position
2. Pelvic
3. Subcecal
4. Preilieal
5. Postileal
CECUM, ASCENDING &
DESCENDING COLON
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1.
2.
3.
ANTERIOR RELATIONS:
Coils of small intestine
Greater omentum
Anterior abdominal wall
1
2
Iliac crest
5
3
4
6
1: Iliohypogastric nerve; 2: Ilioinguinal nerve; 3: lateral cutaneous nerve of thigh
4: Femoral nerve; 5: Genitofemoral nerve; 6: Obturator nerve
P.M.= psoas major; Q.L.=quadratus lumborum; I.=iliacus;
T.A.= transversus abdominis
1
2
5
3
6
4
1: Iliohypogastric nerve; 2: Ilioinguinal nerve; 3: lateral cutaneous nerve of thigh
4: Femoral nerve; 5: Genitofemoral nerve; 6: Obturator nerve
P.M.= psoas major; Q.L.=quadratus lumborum; I.=iliacus;
T.A.= transversus abdominis
CECUM, ASCENDING &
DESCENDING COLON
• POSTERIOR RELATIONS:
• Cecum: psoas major, genitofemoral nerve,
iliacus, lateral cutaneous nerve of thigh,
femoral nerve
• Ascending colon: iliacus, lateral cutaneous
nerve of thigh, quadratus lumborum,
ilioinguial nerve, iliohypogastric nerve, iliac
crest, origin of transversus abdominis from
lumbar fascia
• Descending colon: relations of cecum +
relations of ascending colon + left kidney
RELATIONS OF
TRANSVERSE COLON
RELATIONS OF
TRANSVERSE COLON
• ANTERIOR: greater omentum, anterior
abdominal wall
• POSTERIOR: 2nd part of duodenum,
head of pancreas, coils of small
intestine
• SUPERIOR: liver, gall bladder, stomach
• INFERIOR: coils of small intestine