gut and peritoneal cavity Flashcards
what is the peritoneum
lines the abdominal cavity
single continuous membrane of squamous epithelium - mesothelium
capillary thin layer - full of fluid - allow organs to slide over each other
what is the abdominal cavity
the whole of the abdomen
what is the peritoneal cavity
potential space within layer of peritoneum
intraperitoneal structures
most of SI
suspended from the abdominal wall by mesenteries
retroperitoneal structures
kidney ureters adrenal glands lumbar plexus sympathetic trunk oesophagus duodenum - except 1st part pancreas except tail colon - not transverse great vessel lie between parietal peritoneum and abdominal wall
which of the retroperitoneal organs are secondary
duodenum
pancreas
colon
formation of the lesser sac
as liver grows it moves to the R and dorsal mesentery and spleen move to the L
original R side of the upper peritoneal cavity is now posterior - this is the lesser sac
lesser sac only in foregut region
it is behind the liver and stomach
behind the lesser omentum`
lesser and greater sac
2 regions of the peritoneal cavity
in communication with each other via foramen
peritoneal compartments
supracolic compartment - above transverse colon
infracolic compartment - below the transverse colon
gutters in the peritoneal cavity`
R and L paracolic gutter
where will absess and inflammatory exudate in the R supracolic cavity travel
down R paracolic gutter
then to pelvic area
not to left side because pf falciform ligament `
direction of movement of peritoneal fluid
move up to underside of the diaphragm
via gutters
cancer moves up too
great vessels
inferior vena cava lies to the R of the abdominal aorta
great veins develop in a plane anterior to the arteries - L renal vein crosses anterior of aorta, R renal artery posterior to IVC
primary retroperitoneal structures
abdominal aorta and branches IVC kidneys and ureters adrenal glands nerves - lumber plexus from spinal cord and sympathetic trunk
what does primary retroperitoneal mean
developed outside the parietal peritoneum
never had a mesentery
greater omentum
large peritoneal fold that attaches to greater curvature of the stomach and first part of the duodenum
drapes over transverse colon and jejenum and ileum
posteriorly ascends to adhere to peritoneum on superior surface of te transverse colon and anterior layer of transverse mesocolon before arriving at posterior abdominal wall
contains an accumulation of fat
2 arteries and accompanying veins - R and L gastro-omental vessels between double layer of apron - inferior to greater curvature 0f stomach
from lower part of the dorsal foregut mesentery
double fold
anterior to the intestine
transverse colon mesentery
transverse colon is intraperitoneal
mesentery is the transverse mesocolon
it is attached to inferior surface of greater omentum
sigmoid colon mesentery
sigmoid mesocolon
at the brim of the pelvis
mesentery of the liver
convex surface of liver attached t0 diaphragm and anterior abdominal wall by fold of mesentery - falciform (sickle shaped) ligament
ligamentum teres
remains of the umbilical veins
lesser omentum
sheet of mesentery that connects inferior surface of liver to lesser curvature of stomach
free edge contains hepatic artery, HPV and bile duct
free edge passes through epiploic foramen to enter a pocket of peritoneal cavity posterior to the stomach
this is the lesser sac of the peritoneal cavity
from the ventral foregut mesentery
contains the portal vein, hepatic artery and bile duct - run between posterior abdominal wall and the lesser omentum
ventral mesentery ends at start of midgut so there is a free edge.
foregut development
stomach and beginning of duodenum
develops suspended by dorsal and ventral mesentery
liver development
in the ventral mesentery
dividing it into a sheet between liver and gut - the lesser omentum
spleen development
develops in proximal part of dorsal foregut mesentery
dividing it into a part between the stomach ang the spleen - the gastrosplenic ligament
and a part between the spleen and posterior abdominal wall - the lieno-renal ligamen
what are mesenteries
peritoneal reflections where the components of the GI tract are stored
attach viscera to the abdominal wall
conduit for vessels, nerves and lymphatics
visceral peritoneum
surrounds the suspended organs
parietal peritoneum
lines the abdominal wall
dorsal and ventral mesenteries
entire gut tube supported by dorsal mesentery
foregut has a ventral mesentery
ventral mesentery
contains the liver
split into:
falciform ligament - anterior to the liver
lesser omentum - posterior to the liver
mesenteries in relation to stomach, liver and spleen
falciform ligament - connects upper surface of liver to the anterior abdominal wall
lesser omentum, separated into gastrohepatic ligament and hepatoduodenal ligament, attach liver to stomach
gastrosplenic ligament - stomach to spleen
splenorenal ligament - spleen to kidneys
liver mesenteries
liver develops in ventral foregut mesentery
pyloric sphincter
ring of muscle - prevent food entering duodenum
can palpate it
internal structure of stomach
rugae - fixed longitudinal folds in mucosa
how is the gut tube attached to the abdomen
suspended from the posterior abdominal wall
by peritoneal fold - dorsal mesentery
first part of the duodenum
duodenal cap - most ulcers are here
horizontal R-L from pylorus of stomach to position anterior to R hilum of kidney
5cm long
L1 level
2nd part
contains entrance for the common bile duct - major duodenal papilla, and pancreatic ducts
descending
7-10cm R of L1-3
root of transverse mesocolon crosses it
3rd part of the duodenum
run L inferior 6-8cm cross L3 crossed anteriorly by superior mesenteric artery and vein
4th part of duodenum
ascending
become continuous with jejunum
5cm
L2
relations between the duodenum and pancreas
duodenum is G shaped - curled around origen of superior mesenteric artery
head of pancreas lies in curve of duodenum
uncinate process hooks around superior mesenteric artery
neck and body run towards ileorenal ligament
tail of panc reaches hilum of spleen
position of duodenum and pancreas in abdomen
duodeno-pancreatic block lies anterior to vasculo-renal plane
first 2cm of duodenum
intraperitoneal
anterior to bile duct, portal vein and gastroduodenal artery
arteries and veins that supply the midgut
arteries: jejunal or iliac branches of mesenteric artery
jejunal and ileal veins - from the superior mesenteric vein which joins portal vein via the liver
nerves
sympathetic
afferent and efferent
from lower thoracic spinal nerves via splanchnic nerves and superior mesenteric ganglia
lymphatics
vessels drain the superior mesenteric lymph nodes
jejunum
proximal 2/5 larger in diameter than ilium upper L quadrant of abdomen less prominent arterial arcades longer vasa recta
ileum
distal 3/5 smaller in diameter lower R quad of abdomen prominent arterial arcades shorter vasa recta
large intestine
cecum - start ascending colon transverse colon descending colon sigmoid colon tenia coli - muscular layer glands locate at epiploicae
blood supply
blood supplies arise form anterior aorta
unpaired arteries
coeliac trunk - foregut, panc, liver, spleen
superior mesenteric artery - midgut
inferior mesenteric artery - hindgut - large
branches of the coeliac trunk
L gastric artery
splenic artery
common hepatic artery
branches of superior mesenteric artery
middle colic artery R colic artery ileocolic artery ileal artery jejunal arteries
branches of the inferior mesenteric artery
L colic artery
superior rectal artery
ssigmoid arteries
where is the change from superior mesenteric artery to inferior mesenteric artery supply
left flexure of colon ie change from mid to hind gut
venous drainage
drain into the portal vein
superior mesenteric v drain everything supplied by superior mesenteric artery
descending, splenic colon and rectum - inferior mesenteric vein
inferior mesenteric vein drain into splenic vein
spenic vein drains stomach
porto-systemic anastomosis
systemic vein and portal vein may anastomose when there is a blockahge/high pressure in the portal system - haemorrhoids
severe venous haemorrhage from oesophagus and rectum
lymphatics
lymphatic drainage follow arterial supply not venous drainage
all lymph drain into cisterna chyli
cysterna chyli - elongated lymphatic sac located in front of L1 and L2 bodies
thoracic duct commences from the cisternae chyli
innervation
viscera - supplied by autonomic nervous system
sensory fibres important
PNS sensory rate of contraction, peristalsis and secretion of glands- vagus nerves, pelvic splanchnic nerves - S2 S3
sympathetic sensory - pain in duct region, closure of sphincter: thoracic splanchnic T5-12
lumbar splanchnic L1 and 2
would work without oine
thoracic splanchnic nerves
greater splanchnic nerves - T5-9
lesser 10-11
least 12
flexures of the colon
the R and l are in contact with lower pole of kidney
root of transverse mesocolon runs across 2nd part of duodenum and along pancreas
