Abdomen
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Abdomen is the part of
the trunk between the
thorax and pelvis.
It is covered by the
musculoaponeurotic
walls anterolaterally,
the diaphragm
superioly, and muscles
of the pelvis inferiorly,
which are suspended
between and supported
by the inferior thoracic
skeleton, pelvic girdle
and semirigid lumbar
vertebrae posteriorly.
Abdomial Regions
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Two vertical lines
midclavicular lines
Two horizontal lines
subcostal plane and
trans tubercular plane
R. & L.
Hypochondriac
Epigastric
R. & L. Lumbar
Umbilical
R. & L. Iliac
Hypogastric or
pubic
Abdominal wall
The wall consists of skin and
subcutaneous tissue(superficial fascia)
composed of fat,muscles and their
aponeuroses and deep fascia, and parietal
peritoneum
 Inferior to umblicus, the subcutaneous
tissue has two layers
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 Superficial fatty layer(camper fascia)
 Deep membranous layer(scarpa fascia)
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The membranous layer continues
inferiorly to perineal region as superficial
Muscles of the abdominal wall
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3 flat muslces(external oblique,internal
oblique and transverse abdominal) and 2
vertical muscles(rectus abdominus and
pyramidalis)
Esophagus
Esophagus, a muscular tube is continuous
with laryngopharynx.
 The pharyngoesophageal junction has the
superior esophageal sphinchter, a
constriction producted by the
cricopharyngeal part of the inferior
constrictor muscle, is the narrowest part
of esophagus
 When the esophagus is empty it has a slit
like lumen which expands when the food
bolus descends.
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The cervical esophagus lies between
trachea and cervical vertebral column.
 The esophagus remains posterior to the
arch of aorta, left main bronchus and left
atrium and then it passes through the
esophageal hiatus in the diaphragm at the
level of T10 vertebrae.
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thoracic esophagus
The thoracic esophagus has 3
constrictions because of the compression
of
 Cervical constriction: at the beginning of
phryngo-esophageal junction
 Thoracic constriction: compound
constriction caused by the compression of
arch of aorta and left main bronchus
 Diaphragmatic constriction: when it
passes thru the diaphragm
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Abdominal esophagus
Abdominal esophagus after passing
through the esophagus is only 1.25cm
long and it ends in the cardiac orifice of
the stomach.
 Gastro esophageal junction lies at the levl
of t11 at the tip of xiphoid process.
 Immediately superior to this junction, the
diaphragmatic musculature forms the
physiologic eesophageal sphincter
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stomach
The stomach is the expanded part of the
alimentary tract between the esophagus
and the small intestine.
 Its functions are
1. Acts as a reservoir of food
2. Enzymatic and mechanical digestion
 An empty stomach is only slightly larger
than large intestine which it is capable of
considerable expansion that it can hold
2-3 L of food.
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Stomach
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The stomach has 4 parts
Cardia: the part
sorrounding the cardiac
orifice
Fundus: the dilated
superior part
Body: the major part of
stomach between the
fundus and the pyloric
antrum.
Pyloric part: funnel
shaped outflow region of
stomach
Small intestine
Primary site for
absorption of
nutrients.
 Has 3 parts:
1. Duodenum
2. Jejunum
3. ileum
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Duodenum
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Shortest,widest and
more fixed part of
small intestine
Bile and main
pancreatic ducts enter
through
Hepatopancreatic
ampulla
Celiac trunk and
superior mesentric
artery supplies the
blood.
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Jejunum and ileum
together is 6-7 m
long.
Superior mesentric
artery(direct branch of
aorta) supplies the
jejunum and ileum
Large intestine
Water is absorbed from
indigestible residues of
liquid chyme, converting
it into feces.
 It consists of
1. Cecum
2. Appendix
3. Ascending colon
4. Transverse
5. Descending
6. Sigmoid
7. Rectum
8. Anal canal
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Cecum and appendix
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Cecum is blind
intestinal pouch
approximately 7.5cm
in both length and
breadth, located in
the right lower
quadrant.
Appendix is a blind
intestinal diverticulum
containing masses of
lymphoid tissue
Appendix arises from the postero medial
aspect of the ceum inferior to the ileocecal
junction.
 The cecum is supplied by the ileocolic
artery, the terminal branch of SMA.
 The appendicular artery, the branch of
ileocolic artery supplies the appendix
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colon
The ascending colon is narrower than
cecum.
 Ileocolic and right colic arteries, the
branches of SMA supplies the ascending
colon.
 The transverse colon is 45 cm long and is
most mobile part of large intestine,
extending from right to left colic flexure
 Middle colic artery,branch of SMA supplies
the transverse colon.
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Descending colon passes anterior to the
lateral border of left kidney
 Sigmoid colon is characterized by the Sshaped loop of variable length
 The arterial supply is thru left colic and
sigmoid arteries, branches of inferior
mesentric artery.
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Rectum is the
fixed terminal
part of large
intestine,has 3
sharp lateral
flexures
 Superior,interme
diate and
inferior.
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