Dispostion of peritoneum Flashcards
Due to differential growth, what ways do the embryo begin to fold during the 4th week?
fold in both cranio-caudal and lateral planes
Where do the lateral folds fuse?
fuse in the midline: splanchnic layers meeting splanchnic layers, somatic layers meeting somatic layers.
What forms the primitiative gut?
The enclosed endoderm (continuous with the yolk sac) and surrounding splanchnic mesoderm forms a tube
What is the yolk sac now called after the folding of the lateral folds
umilical vesicle
What does the coelom become in the abdominal region?
the peritoneal cavity
What separates the thorax from the abdomen ?
Septum transversum, which has descended with the cardiogenic area during head folding
The septum transversum also contributes to..?
contributes to the respiratory diaphragm, ventral mesentery and liver.
What are the walls of the peritoneal cavitty lines with?
parietal peritoneum
what is the peritoneum derived from?
mesenchymal cells;
what does the peritoneum do?
secretes a small amount of serous fluid for lubrication between surfaces of organs that extend into it.
what is ascities?
abnormal accumulation of fluid in the peritoneal cavity due to some disease process.
What does the parietal peritoneum line?
Lines the wall of the abdominal and pelvic cavities.
What is beneath the parietal peritoneum?
layer of connective tissue called the extraperitoneal layer (fatty
What does the visceral peritoneum cover?
Covers the organs (viscera) suspended into the abdominal and pelvic cavities.
are the visceral and parietal peritoneum continuous with each other?
yes
What are the 3 specializations of the peritoneam
mesentery - omentum- ligament
what is the mesentery made up of?
2 layers of peritoneum
What is the omentum?
Folds of peritoneum connecting the stomach to another organ.
What happens to the somatic mesoderm
during the trilamniar disk folding, it becomes the trunk wall lined with peritoneum
THe somatic mesoderm is continuous with
the splanchinic mesoderm
Where is the somatic mesoderm continuous with the splanchnic mesoderm
at dorsal and ventral mesenteries, walls of the foregut (and its derivatives) visceral peritoneum
the dorsal mesentery is continous with?
ventral mesentrary
What is the yolk sac made from
the endoderm of the viscera,
who does the yolk sac have continuity with
UMBILICUS
Where is the greater sac of the peritoneal cavity?
extends across entire breadth of abdomen, from diaphragm to pelvis,
what are the organs in the greater sac of the peritoneal cavity said to be
either peritoneal or intraperitoneal
What forms the lesser sac (omental bursa)
rotation of the gut
where is the lesser sac
behind the stomach, liver, lesser omentum, part of the greater omentum
what does the lesser sac communicate with
the greater sac via epiploic foramen
What does the greater omentum connect, how many layers is it?
stomach to transverse colon, four layers and potential space, 4
where is the lesser onmentum
stomach and part of the duodeum to lvier
what are the 3 parts of the greater omentum
gastrocolic, gastrosplenic, gastrophrenic
between the 4 layers of the greater omentum is what
a potential space,
what is the lesser omentum derived from?
ventral mesentery.
what are the two parts of the lesser omentum
hepatoduodenal and hepatogastric ligaments
what are the greater and lesser sacs connceted by
Omental (Epiploic) Foramen=foramen winslow
the peritoneal refections on the posterior wall form what other structures?
Mesentery, greater omentum and assorted ligaments.
where deos the dorsal mesentery run to and from?
the esophagus all the way to the rectum
where does the ventral mesentery run? and contribute to?
contributes to the falciform ligament. It extends only as far as the umbilicus, the midgut.
the endoderm lining of the gut tube derived from what?
the yolk sac
the splanchic mesoderm around the gut tube with differentiate into?
layers of smooth muscle and connective tissue
where do the umbilical artery and veins lie?
inferior border of the ventral mesentery.
what artery supplies the forgut?
celiac trunk
what artery supplies the midgut?
superior mesenteric artery
what supplies the hindgut?
inferior mesenteric artery.
what determines how mobile an organ is?
its legnth of its mesentary
what is an organ that only has peritoneum on their anterior surface
extraperitoneal or retroperitoneal.
what are the three parts of the small intenstine?
duodenum, jejunum, ileum
Where is the duodenum located?
partly retroperitoneal
What is the jejunum and ileum are suspended by
Mesentery
how do you know youre at the transtion bwtn the jejunum and duodenum?
Jejunum begins when the intestine becomes intraperitoneal, at the duodenal-jejunal flexure.
What supports the D-J transition?
suspensory muscle (ligament) of the duodenum
what is a Paraduodenal hernia:
ntestine can strangulate in the paraduodenal fossa
the decdeing and ascending colon are what orietation in the abdomen?
secondary retroperitoneal because their mesentery disappears
whats the function of the sigmoid mesocolon
suspends the sigmoid colon from posterior wall
What does the paracolic gutters do?
direct the flow of fluids (ascites, blood, pus, errant cancer cells, infection) toward the pelvis when the individual is standing. The R infracolic space is blind ended.
what are the peritoneal attachments of the slpeen?
gastrosplenic and splenorenal ligaments
waht ligaments does the liver have?
Falciform Ligament and the Ligamentum Teres in the free border
Ligementum teres is a remnant of what fetal stucture?
fetal left umbilical vein
what are the lobes of the liver?
right, left, behind is the quadrate and caudate
what does the liver develp from?
septum transversum.
waht else delevops from the septum transversum.
diaphragm also derives in part from the septum, as does a part of the ventral mesentery.
what does the biliary apparatus develop from
primitive gut
what does the liver develops within
ventral mesentery
what forms the coronary ligaments on the liver
visceral peritoneum reflects off the liver onto the diaphragm forming the coronary ligaments that surround the bare area, where no peritoneum intervenes between the liver tissue and the diaphragm.
Where are the suphrenic recesses and what do they do?
above the liver, below the diaphragm- sites for
resorption from peritoneal fluid
what does the Hepatoduodenal Ligament contain
portal triad: Common Bile Duct, Artery Proper, Portal Vein
what does the hepatogastric ligament do
encloses right and left gastric artires
what is the nerve supply to the parietal peritoneum?
Innervated by somatic afferent fibers (sensitive to pain, touch, temperature, pressure).
intercostal nerves (lower 6, T7-T12)
phrenic nerves, lumbar nerve (first, L1)
what is the nerve supply to the Visceral peritoneum
Innervated by visceral afferent fibers running with the autonomic nervous system (sensitive to distention-leads to sensation of pain). Visceral pain is less localized and more diffuse.
What organs are derived from the foregut? So whats their blood supply?
Esophagus. Stomach. Duodenum (proximal half) Liver. Gallbladder. Pancreas. Spleen (Note that it is located in the foregut region, but is not a gut organ) CELIAC artery
What organs are derived from the midgut? So whats their blood supply?
Duodenum (distal half of 2nd part, 3rd and 4th parts) Jejunum Ileum Cecum Appendix Ascending colon Hepatic flexure of colon Transverse colon (proximal two-thirds) SUPERIOR MESENTERIC ARTERY
What organs are derived from the foregut? So whats their blood supply?
distal third of the transverse colon and the splenic flexure, the descending colon, sigmoid colon and rectum
INFERIOR MESENTERIC ARTERY
The 1st and 4th part of the duodenum is (intra/retro)peritoneal
intraperitoneal
The 2nd and 3rd part of the duodenum (intra/retro)peritoneal
secondarily retroperitoneal
Whats the fossa called when the duodenum becomes retropertineal>
paraduodenal fossa
what parts of the colon are secondary peritoneal?
ascending and descending colon
What parts of the colon are peritoneal?
transverse colon and sigmoid colon
What peritoneal is the pancreas?
secondary
Bounderies of the lesser sac (Omental bursa)
anteriorly by the quadrate lobe of the liver, the stomach, lesser omentum and gastrocolic ligament. Posteriorly it is marked by the pancreas. Its left lateral margin is made by the left kidney and adrenal gland. Its boundary on the right is made by the epiploic foramen and lesser omentum
What are L1 branches called? What do they supply?
Iliohypogastric Nerve (L1)- muscles, skin of wall, and the parietal peritoneum
What is the parietal peritoneum that lines the diaphram intervatied by?
phrenic
