THE ABDOMINTHE ABDOMIN
The Abdomen is the region of the trunk that
lies between the diaphragm above & the inlet
of the pelvis below.
The abdominal wall:
Superiorly , the abdominal wall is formed by
the diaphragm ,which separates the
abdominal cavity from the thoracic cavity.
Inferiorly the abdominal cavity is continuous
with the pelvic cavity through the pelvic inlet.
Anteriorly ,the abdominal wall is formed by
the lower part of thoracic cage & below by
the rectus abdominus M ,,ext. oblique ,int.
oblique & transverse abdominus M.& fasciae.
The abdominal wallThe abdominal wall
PosteriorlyPosteriorly ,the abdominal wall is formed in the ,the abdominal wall is formed in the
midline by the 5 lumbar vertebrae & their midline by the 5 lumbar vertebrae & their
intervertebra discs,laterally,by the 12intervertebra discs,laterally,by the 12
thth
ribs ,upper ribs ,upper
part of bony pelvis ,the psoas M.,the quadratus part of bony pelvis ,the psoas M.,the quadratus
lumborum M.,& the aponeuroses of origin of lumborum M.,& the aponeuroses of origin of
transversus abdominus Mtransversus abdominus M..
The anterior abdominal wall is divided by 2 The anterior abdominal wall is divided by 2
midclavicular lines longitudanally & subcostal & midclavicular lines longitudanally & subcostal &
inter tubercular lines transeversly to 9 regionsinter tubercular lines transeversly to 9 regions::
right & left right & left hypochondriumhypochondrium& & epigastricepigastric area in area in
between., right & left between., right & left lumbar lumbar areas & areas & umbilicusumbilicus
area in between & right & left area in between & right & left iliac fossae(inguinal)iliac fossae(inguinal)
& & hypogastrichypogastric area in between area in between..
The abdominal wallThe abdominal wall
The abdominal wall formed from
1 -the skin : which supplied by the ant. Rami
of the lower 6 thoracic & 1
st
lumber Nn.
(which is the ilio-hypogastric & ilio-inguinal
Nn.).
T7 supply the skin of epigastric area,T10
supply the umbilicus&L1supply area above
the inguinal lig.& the symphysis pubis.
2 -The superficial fascia :which divided to
superficial fatty layer & deep membranous
layer.,the fatty layer changed in the scrotum
to dartos M.
The abdominal wallThe abdominal wall
3 -the deep fascia :it is a thin layer of aleolar
tissue covering the mm .
4 -the muscular layer : consist of 3 broad thin
sheets that are aponeurotic in front (ext. oblique
, int. oblique & trasversus abdominus )also
there is a wide vertical M( the rectus abdominus
M.) which enclosed by the sheet to form the
rectus sheath.
5 -The fascia transversalis :thin layer of fascia
that lines the trasversus abdominus M.& extend
down to form the femoral sheath.
The abdominal wallThe abdominal wall
6 -the extra-peritoneal fat.
7 -the parietal peritoneum
THE INGUINAL CANALTHE INGUINAL CANAL :
It is an oblique passage ( canal ) through the lower
abdominal wall & it allows to pass structures to
& from the testis to abdomen in male,& the round
lig .of the uterus to labium majus in female.& it
transmits the ilio-inguinal N. in both sexes. The
canal is 4 cm long lies above & parallel to the
inguinal lig. Extend from the deep inguinal ring (a
hole in transversalis fascia) down ward &
medially to superficial inguinal ring( a hole in the
aponeurosis of the ext. oblique M.
THE INGUINAL CANALTHE INGUINAL CANAL
The walls of inguinal canal:
The ant. wall :apooneurosis of ext.
oblique M .
The post.wall :the fascia transversalis.
The inf. wall (the floor) : the inguinal lig.
The sup. wall (the roof ): the lowest Ff. of
int. oblique & transversus
abdominis Mm.
THE INGUINAL CANALTHE INGUINAL CANAL
The spermatic cord : is a collection of strs. that
pass through the inguinal canal to & from
the testis , it is formed from :
1 -The vas deferens.
2 -the testicular artery.
3 -The testicular veins (pampiniform plexus).
4 -Testicular lymph nodes.
5 -autonomic Nn.
6-processus vaginalis.
7 -Cremasteric A.
8 -Artery to vas deferens.
9 -Genital br. Of genito-femoral N.
The spermatic cordThe spermatic cord
The spermatic cord covered by 3 concentric
layers of fascia derived from the layers of
ant. Abdominal wall:
1 -The external spermatic fascia derived from
the ext. oblique aponeurosis.
2 -Cremastric fascia derived from the int.
oblique M.
3 -Internal spermatic fascia derived from the
fascia transversalis.
The scrotumThe scrotum
It is an outpouching of the lower part of the
ant. Abd. Wall . It contains the testes , the
epididymides & the lower end of spermatic
cord.
The wall of the scrotum has the fallowing
layers: the skin ,superficial fascia( dartos M.
replace the fatty layer) , The external
spermatic fascia , Cremastric fascia ,
Internal spermatic fascia & tunica vaginalis.
THE ABDOMINAL CAVITYTHE ABDOMINAL CAVITY
The peritoneum
It is a serous membrane lining the wall of the
abdomen & the pelvic cavities (= parietal P.) &
clothing the abdominal & pelvic viscera (=visceral
P) , the space between them called the peritoneal
cavity which contain small amount of
fluid .Between the parietal P. & the fascia covering
the abd. Is a layer of connective tissue called the
extra-peritoneal tissue. The organs which are
covered totally with visceral P. called intraperitoneal
organs while those covered partially or lying behind
the P. called retroperitoneal organs.
The omentum: is 2- layers folds of P. that
connects the stomach to other viscus.
The greater omentum connects the stomach
to transverse colon ,The lesser omentum
connect the stomach to liver.
The mesentery is a 2-layers folds of P.
connecting parts of intestine to the post.
abd. wall. e.g. mesentery of small int., the
transverse colon, The sigmoid colon.
The Parietal P. is sensitive to pain,temp.,touch
& pressure & supplied by lower 6 thoracic &
1
st
lumber Nn. while the visceral P. sensitive
to strech& tearing& supplied by autonomic
N.S.
The gastrointestinal tractThe gastrointestinal tract
The osophagus : is a muscular collapsible tube ,25
cm long, joins the pharynx to the stomach, its
major part in the thorax, enters the abdomen
through an opening in the right crus of the
diaphragm &enter the stomach on its right side.
The stomach :It is J-shape organ lies under cover
of the lower ribs, has cardiac orifice above &
pyloric orifice below,& has greater & lesser
curvitures , & ant. & post. Surfaces.
It devided to :fundus,body ,incisura angularis ,
antrum , pyloric canal & pyloric sphincter.
The StomachThe Stomach
The lesser curvature :forms the right border & extends
from the cardiac orifice to the pylorus. It is suspended
from the liver by the lesser omentum.
The greater curvature :forms the left border, the greater
omentum extends from the lower part to the
transverse colon & the gastro-splenic omentum
extend from the upper part to the spleen.
The mucus membrane forms many folds called rugae
that are longitudinal in direction.
It has 3 muscular layers:longitudinal , circular & oblique.
The stomach function is :storage of food ,mix the food
with gastric secretions to form chyme, & the delivery of
the chyme to the small intestine .
The small intestineThe small intestine
It extends from the pylorus to the ileo-cecal
valve & divided to duodenum , the jejunum
& the ileum.
The duodenumThe duodenum : is a C- shape tube ,25 cm
long, joins the stomach to the jejunum . It
receives the opening of the bile &
pancreatic ducts & curves around the head
of pancreas. It divided to 4 parts:
1
st
part is 5cm long, begins at pylorus & runs
upward & backward on the right side of L1
vertebra.
The duodenumThe duodenum
The 2
nd
part: is 8 cm long runs vertically downward
in front of the right kidney & on right side of L1,2
vertebrae. Its medial border receives the bile duct
& the main pancreatic ducts in major duodenal
papilla & receive the accessory panc. Duct higher
up in the minor duod. Papilla.
The 3
rd
part: is 8 cm long ,runs horizontally to the
left, in front of the vertebral column& the lower
margin of the head of panc.
The 4
th
part: is 5 cm long, runs upward & to the left
to the duodeno-jejunal flexure.
The mucus memb. Is formed in circular folds called
Plicae circularis.
The Jejunum & The IleumThe Jejunum & The Ileum
It is 6 m long. The jejunum is the upper 2/5
th
of
this length start in duodeno-jejunal junction
to merge with the ileum which end in the
ileo-cecal junction.
The coils of them are freely mobile & attached
to the post. abd. wall by fan – shape fold of
peritoneum called Mesentery of the small
intestine.
The jejunum has wider-bored, thicker-walled ,
redder & less fat than the ileum ,also the
plicae circulares are larger ,more numerous
& closely set.
The Large IntestineThe Large Intestine
It extends from the end of the ileum to the anus. It
divided to Cecum , Appendix ,ascending
colon ,Transverse colon ,Descending colon ,Sigmoid
colon , Rectum & Anal canal.
Its function is absorption of water & electrolytes& the
storage of undigested material until it can be expelled
from the body as feces.
The Cecum : It is a blind-ended pouch located in the
right iliac fossa , attached to its postero-medial surface
is the appendix. The longutudinal Mm. folded in 3
strips called the teniea coli which covered the base of
the appendix.The ileum enter the large int. at the
junction of the cecum with the ascending colon in the
ileo-cecal valve.
The Large IntestineThe Large Intestine
The Appendix :is a narrow muscular tube contain
large amount of lymphoid tissue ,its base lies
below the ileo-cecal junction & attached by the
meso-appendix to the mesentery of the small
int.The tip lies in many positions like retrocecal,
pelvic, paracecal, subhepatic & retro-ileal sites.
The Large IntestineThe Large Intestine
The Ascending Colon :It is 13 cm long ,extend
upward from the cecum to inf. surface of the
liver where it turns to the left forming the
hepatic flexure & become continuous with
the transverse colon.
The Transverse Colon : It is 40 cm long ,
begins at hepatic flexure extend across the
abd. suspended by the transverse
meseocolon, to the splenic flexure where
turns downward to start the descending
colon.
The Large IntestineThe Large Intestine
The Descending Colon : It
is 25 cm long , extend from
the splenic flexure
downward to pelvic brim to
continue with sigmoid
colon,
The Sigmoid Colon :It is 35
cm long ,begins at the pelvic
brim to continue with the
rectum at S3 vertebra .Its
attached to post. pelvic wall
by sigmoid mesocolon where
the left external iliac Vv. & the
left ureter pass..
The Large IntestineThe Large Intestine
The rectum :It is 13 cm long
begins in front of S3 as
continuation of sigmoid colon
to pass downward fallowing the
curve of the sacrum & coccyx to
the tip of the coccyx where
pierce the pelvic diaphragm &
become continuous with the
anal canal . The dialated lower
part called the rectal ampulla.
The Anal Canal :is 5 cm long
extend from the pelvic
diaphragm to the anus opening
& surrounded by the anal
sphincters.
The blood supply of GITThe blood supply of GIT..
The arterial supply of the GIT related to the
development of deferent parts of the gut . The
celiac A. is the A. of the foregut & supplies from
the lower 1/3 of the osophagus to the middle of the
2
nd
part of the duodenum.
The sup. Mesenteric A .is the A. of the midgut &
supplies from the middle of the 2
nd
part of the
duodenum to distal 1/3 of the transverse colon.
The inf. Mesenteric A. is the A. of the hindgut
&supplies the large int. from distal 1/3 of the
transverse colon down to half of the anal canal.
The celiac arteryThe celiac artery
It arise from the abdominal aorta at T12 level, It
gives 3 branches:
1 -The left gastric A. to lesser curvature of the
stomach &lower Esophagus to anastamose
with the right gastric A..
2 -The splenic A: run on the upper border of
the pancreas & behind the stomach to enters
the spleen . It gives:
2-1 -pancreatic branches.
2-2 -left gastro-epiploic A. on the greater
curvature of the stomach to anastamose with
the right gastro-epiploic A.
The celiac arteryThe celiac artery
2-3 -Short gastric Aa. to the fundus of the stomach.
3 -The Hepatic A. which gives:
3-1 -right gastric A. runs on the lesser curvature to
anastamose with the left gastric A.
3-2 -Gastro-duodenal A. runs behind the 2
nd
part of
the duod. to divide to right gastro-epiploic A (on
the greater curvature) & superior pancreatico-
duodenal A. which descend between the 2
nd
part of
the duod. & the head of pancreas.
3-3 -Right & left hepatic Aa. that enter the porta
hepatis. The right hepatic A. gives the cystic A. to
the gall bladder
The superior mesenteric arteryThe superior mesenteric artery
It is the A. of the midgut . It arise from the abd.
aorta below the celiac A. to run downward
behind the neck of the panc.& in front of the
3
rd
part of the duod. Its branches are:
1 -the inf. Pancreatico-duodenal A.
2 -middle colic A to supply the trans. colon
3 -right colic A. to supply the ascen. colon.
4 -Ileo-colic A. which supply the small int.
,cecum (by cecal br.) & appendix( by
appendicular A.)
5 -jejunal & ileal branches.
The inferior mesenteric AThe inferior mesenteric A..
It is the A. of the hindgut, arise from the aorta 4
cm above its bifurcation to pass downward
& to the left. Its branches are:
1 -left colic A.
2 -sigmoid A.
3 -superior rectal A.
The marginal A.: form from the anastmosis of
the colic A. Around the concave margin of
the large int. It starts at the ileo-caecal
junction to the sup rectal A.
Venous Drainage of GITVenous Drainage of GIT::
The greater part of the GIT & its accessory organs
drain to the liver by the portal venous system.
THE PORTAL VEIN: is 5 cm long formed behind the
neck of the panc. by the union of sup. Mesenteric
vein & the splenic vein then it ascend to the right
behind the 1
st
part of the duod. to enter the lesser
omentum then to porta hepatis where divided to
right & left terminal branches.
The portal circulation start as a capillary plexus in
the organ it drains & ends by emptying in the liver.
The tributaries of the portal veinThe tributaries of the portal vein::
1- the splenic vein which receive the short
gastric ,left gastroepiploic ,inf. Mesenteric
& pancreatic veins .
2- the inf. Mesen. V. which joins the splenic V.
& receive the sup. Rectal V. ,sigmoid V. &
left colic V.
3-The sup. Mesen. V .it pass in front of the 3
rd
part of duod. to join the splenic V. behind
the neck of the panc. It receives the jejunal ,
ileal, lieocolic ,right colic, middle colic, inf.
pancreaticoduodenal & right
gastroepiploic Vv.
The tributaries of the portal veinThe tributaries of the portal vein
4 -left gastric vein.
5 -right gastric vein.
6 -cystic veins : which drains the gall bladder.
Portal systemic anastamosis:
1 -at the lower end of eosophagus:(left gastric V &
eosophageal V) .
2 -at anal canal (sup. rectal Vv &middle& inf. Rectal
Vv).
3-paraumbilical V.(left br. Of portal vein& veins of ant.
Abd. Wall ).
4 -the veins of asc.colon , desc. colon, duod., panc.&
liver with renal , lumbar & phrenic veins.
THE LIVERTHE LIVER
The largest gland in the body. It divided to large right
lobe & small left lobe by the attachment of the
peritoneum of the falciform lig. The right lobe
divided to qudrate lobe & cuadate lobe by the
presence of gall bladder.
The porta hepatis (=hilum of the liver )lies between
the cuadate & quadrate lobes. It receives the R. &
L.hepatic ducts,R.&L. br. Of hepatic A.,portal
vein ,symp.& parasymp.N Ff.& hepatic lymph
nodes.
The arterial supply of the liver by the hepatic A(br. Of
celiac A.),& the portal vein (enter the porta hepatis)
& the venous drainage by the hepatic veins (2 veins
emerge from the post. surface to the inf. Vena cava.
The Bile DuctsThe Bile Ducts
The bile ducts of the liver consists of the right
& left hepatic ducts which unite outside the
liver to form the common hepatic duct
which descend to receive the cystic duct to
form the common bile duct then descend
behind the 1
st
part of the duod to enter the
medial wall of the 2
nd
part after joining with
the main panc. duct to open in the ampulla
of vater which opens in the lumen of the
duod. by the major duod papilla. The
ampulla of vater surrounded by circular M
called the sphincter of oddi.
THE GALL BLADDER : is a pear-like sac lying
on the under surface of the liver, divided to
fundus ,body , neck which continue with the
cystic duct.
THE PANCREAS: It is an exocrine( produce
enzymes& secreted by the main panc.duct &
accessory duct) & endocrine (islets of
lungerhans produce insulin & glucagon)
gland lies on the post. abd. wall behind the
peritoneum, divided to head , neck , body &
tail.
THE SPLEEN: It is the largest single mass of
lymphoid tissue, lies under the left
diaphragm close to the 9
th
,10
th
& 11
th
ribs .
The peritoneum surround the spleen
condensated to the greater curvature of the
stomach forming the gastro-splenic lig. & to
the left kidney forming the lieno-renal lig.
THE KIDNEYS :reddish-brown str. lies behind
the peritoneum high up on the post. abd.
wall, the right K. is lower than the left
because of the liver. they covered by fibrous
capsule ,perirenal fat, renal fascia then
pararenal fat.
The kidney divided to cortex & medulla.
THE URETERS : It is 25 cm long muscular
tube extend from the kidney downward on
the Psoas M . In the retro peritoneal space
to enter the pelvis then to the post. surface
of the urinary bladder .
THE SUPRA RENAL GLAND :yellowish
retroperitoneal organs on the upper pole of
the kidney, surrounded by the renal fascia
divided to cortex & medulla.
ARTERIES ON THE POST. ABD.WALLARTERIES ON THE POST. ABD.WALL
THE AORTA : It enters the abd. through the
aortic opening of the diaphragm at T12
level. It descends behind the peritoneum on
the ant. surface of the bodies of lumbar vert.
then at L4 level it divided to 2 common iliac
Aa. It gives branches:
1 -three ant. Visceral br. :celiac , sup.
Mesenteric & inf. Mesenteric Aa.
2 -three lateral br.:supra renal , renal &
testicular or ovarian Aa.
3 -three terminal br.: two common Iliac Aa&
median sacral A.
ARTERIES ON THE POST. ABD.WALLARTERIES ON THE POST. ABD.WALL
The common iliac Aa.: are the terminal br. of
the aorta, at L4 level ,runs downward &
laterally along the med. border of the Psoas
M. each A. ends in front of sacro-iliac jt. by
dividing to ext.& int. iliac Aa. The ureter
pass in front of the bifurcation.
The ext. iliac A.: pass on the medial border of
Psoas M. it gives : inf. Epigastric & deep
circumflex iliac Aa. Then enters the thigh
behind the inguinal lig. to form the femoral
A.
The int. iliac A. :pass in front of sacro-iliac
joint to pass to the pelvis.
Veins on the posterior abdominal wallVeins on the posterior abdominal wall
The inferior Vena Cava :It conveys most of the
blood of the body below the diaphragm to
the right atrium of the heart. It is formed by
the union of the common iliac veins at L5
level . It ascend on the right side of the aorta
pierces the diaphragm at T8 level.& drains
to the right atrium. Its tributaries are:
1-Ant. Visceral trib. the hepatic veins.
2 -three lateral visceral trib.: right supra renal
(
left vein to the left renal vein ,
)
renal veins &
right testicular or ovarian vein( the left vein
drains to left renal vein).
3 -five lateral abd. Wall tributaries : the
inf .phrenic vein & 4 lumbar veins.
4-three veins of origin :2 common iliac veins
& median sacral vein.