peritoneum, peritoneal cavity, stoamch and neurovascular supply to GI system Flashcards
what is the peritoneum?
a continuous membrane which lines the abdominal cavity and covers the abdominal organs (abdominal viscera). it acts to support the viscera and provides pathways for blood vessels and lymph to travel to and from the viscera
what are the 2 layers of peritoneum and what are they made up of?
- parietal and visceral — continuous with each other
- both made up of simple squamous epithelial cells called mesothelium
what lines the internal surface of the abdominopelvic wall?
parietal peritoneum
what is the parietal peritoneum derived from?
somatic mesoderm in embryo
what is the parietal peritoneum sensitive to?
pain (well localised), pressure, laceration and temperature
the parietal peritoneum receives the same _____ supply as the region of the abdominal wall that it lines — therefore pain is _____ from the parietal peritoneum
- somatic
- well localised
what invaginates to cover the majority of the abdominal viscera?
visceral peritoneum
what is the visceral peritoneum derived from?
splanchnic mesoderm in the embryo
the visceral peritoneum has the same _____ supply as the viscera it covers
autonomic
pain from visceral peritoneum?
poorly localised
what is the visceral peritoneum sensitive to?
stretch and chemical irritation
where is pain from the visceral peritoneum referred to?
areas of skin (dermatomes) which are supplied by the same sensory ganglia and spinal cord segments as the nerve fibres innervating the viscera
which peritoenum has somatic/autonomic innervation?
parietal = somatic
visceral = autonomic
what is the only place that the parietal t peritoneum can’t localise?
inferior part of diaphragm — to shoulder - C3/4/5
C3 4 5 KEEPS DIAPHRAGM ALIVE
what is the peritoneal cavity?
a POTENTIAL SPACE between the parietal and visceral peritoneum. it normally contains only a small amount of lubricating fluid
what are intraperitoneal organs covered in?
visceral peritoneum which covers the organ both anteriorly and posteriorly
give examples of intraperitoneal organs
stomach, liver, spleen, appendix, transverse colon
what are retroperitoneal organs covered in?
parietal peritoneum — the peritoneum only covers their anterior surface
what groups can the retroperitoneal organs further be divided into?
> primarily retroperitoneal organs developed and remain outside of the parietal peritoneum. the oesophagus, rectum and kidneys are all primarily retroperitoneal
> secondarily retroperitoneal organs were initially intraperitoneal, suspended by mesenteric. through the course of embryogenesis, they became retroperitoneal as their mesenteric fused with the posterior abdominal wall. thus, in adults, only their anterior surface is covered with peritoneum. examples include the ascending and descending colon
mnemonic for retroperitoneal organs
SAD PUCKER
S - suprarenal (adrenal) glands
A - aorta/IVC
D - duodenum (except proximal 2cm, the duodenal cap)
P - pancreas (except tail)
U - ureters
C - colon (ascending and descending)
K - kidneys
E - oesophagus
R - rectum
describe the mesentery
> double layer of visceral peritoneum
connects an intraperitoneal organ to (usually) the posterior abdominal wall
provides a pathway for nerves, blood vessels and lymphatics to travel from the body wall to the viscera
the mesentery of the small intestine is simply called the ‘mesentery’
mesentery related to other parts of the GI system is named according to the viscera it connects to, eg. the transverse and sigmoid mesocolons, the mesoappendix
what are the omenta?
sheets of visceral peritoneum that extend from the stomach and proximal part of duodenum to other abdominal organs
what does the greater omentum consist of?
4 layers of visceral peritoenum
where does the greater omentum extend from and to?
descends from the greater curvature of the stomach and the proximal part of the duodenum, then folds back up and attaches to the anterior surface of the transverse colon
what is the greater omentum sometimes referred to as?
the ‘abdominal policeman’ — because it has a role in immunity : it can migrate to infected viscera or to the site of the surgical disturbance
what does the lesser omentum consist of?
a double layer of visceral peritoneum
what are the lesser omentum attachments?
lesser curvatures of stomach and proximal part of duodenum to the liver
what are the 2 parts of the lesser omentum?
the hepatogastric ligament (the flat, broad sheet) and the hepatoduodenal ligament (the free edge, containing the portal triad)
what is a peritoneal ligament? example?
a double fold of peritoneum that connects the viscera together or connects viscera to the abdominal wall
eg. hepatogastric ligament, a portion of the lesser omentum, which connects the liver to the stomach
pain in retroperitoneal organs may present as what?
back pain
irritation of the diaphragm (eg. as a result of inflammation of the liver, gallbladder or duodenum) may result as what?
shoulder tip pain
referred pain in appendicitis:
initially, pain from the appendix (midgut structure) and its visceral peritoneum is referred to the ______ region. as the appendix becomes increasingly inflamed, it irritates the _____ peritoneum, causing the pain to localise to the ____________
- umbilical
- parietal
- right lower quadrant
what is this describing?
an organ that is suspended from the body wall by a mesentery
intraperitoneal organ
what is this describing?
a double layer of peritoneum that connects the liver with the lesser curvature of the stomach
lesser omentum
what is this describing?
a double layer of peritoneum that connects the greater curvature of the stomach with the transverse colon
greater omentum
what is this describing?
a double layer of peritoneum that connects an intraperitoneal organ with the body wall
mesentery eg. mesentery, transverse mesocolon, mesoappendix
what is this describing?
the serous membrane that lines the inner surface of the body wall
parietal peritoneum
what is this describing?
the fluid-filled potential space between the parietal and visceral peritoneums
peritoneal cavity
what is this describing?
an organ that is pushed up against the body wall and is only partially covered by peritoneum
retroperitoneal organ
what is this describing?
serous membrane that covers the external surfaces of the abdominal organs
visceral peritoneum
Note that the length of the greater omentum is greater than the distance between the _______ and ___________ so it doubles back on itself forming ____ layers that tend to be fused together. It may contain varying amounts of __ and is often referred to as the “______”
- stomach and transverse colon
- 4
- fat
- fatty apron
what does peritoneal fluid contain?
water, electrolytes, leukocytes and antibodies
if fluid accumulates in the peritoneal space, what condition results?
ascites
what is the peritoneal cavity divided into?
greater and lesser peritoneal sacs
- greater - majority of peritoneal cavity
- lesser (aka; omental bursa) - smaller and lies posterior to the stomach and lesser omentum
the greater sac is divided into 2 compartments by what?
the mesentery of the transverse colon (transverse mesocolon)
describe the supracolic compartment
lies above the transverse mesocolon and contains the stomach, liver and spleen
describe the infracolic compartment
lies below the transverse mesocolon and contains the small intestine, ascending and descending colon. it is further divided into left and right infracolic spaces by the mesentery of the small intestine
what are the supracolic and infracolic compartments connected by?
the paracolic gutters — lie between the posterolateral abdominal wall and the lateral aspect of the ascending and descending colon
The ______ recesses are potential spaces in thesupracolic compartment of the greater sac. They are located between the ________ and the ______. There are left and right ______ spaces, separated by the_______ ligamentof the liver.
The subphrenic recesses are potential spaces in thesupracolic compartment of the greater sac. They are located between the diaphragm and the liver. There are left and right subphrenic spaces, separated by thefalciform ligamentof the liver.
Subphrenic abscesses refer to an accumulation ofpusin theleft or right subphrenic space.They are more common on the______side due to the increased frequency of _________ and ruptured _________ ulcers (pus from the appendix can track up to the subphrenic space via the _________).
Subphrenic abscesses refer to an accumulation ofpusin theleft or right subphrenic space.They are more common on therightside due to the increased frequency of appendicitis and ruptured duodenal ulcers (pus from the appendix can track up to the subphrenic space via the right paracolic gutter).
what does the lesser sac (omental bursa) lie posterior to?
lies posterior to the stomach and lesser omentum