GI - Class 2 Flashcards
What are the two parts of the peritoneum?
visceral and parietal layer
Define peritoneal cavity
Potential space between the parietal and visceral peritoneum that contains serous fluid
Through which passage does the two sacs communicate?
epiploic foramen located behind the stomach
Give examples of retroperitoneal organs
kidney, rectum, oesophagus, ascending and descending colon
Give examples of intraperitoneal organs
stomach, liver, spleen, jejunum
Define intraperitoneal organs
Organs completely surrounded by visceral peritoneum
Define retroperitoneal organs
Organs covered on their anterior surface and therefore firmly attached to the posterior wall
Define extraperitoneal organs
Structures in the abdomen-pelvic cavity which are not covered in peritoneum.
Which layer of the peritoneum is more sensitive to heat, pain and pressure?
parietal layer
What are the attachments of the greater omentum?
greater curvature of the stomach to the transverse colon
What are the attachments of the lesser omentum?
lesser curvature of the stomach to the liver
What is the innervation of the parietal peritoneum
Pain from the parietal peritoneum lining the abdominal wall is innervate by the lower 6 thoracic nerves and L1. Thus pain here is somatic and can be precisely localized . Rebound tenderness occurs.
What is the innervation of the visceral peritoneum?
The visceral peritoneum is innervated by autonomic nerves. Pain is often referred, and is dull and poorly localized
Where is pain referred to?
because the GI tract is a midline structure receiving bilateral nerve supply, pain is referred to the midline.
What are the wall muscles of the posterior abdominal wall?
psoas major, iliac, quadrates lumborum
What vertebral level is the opening for the IVC in the diaphragm
T8
What vertebral level is the opening for the oesophagus in the diaphragm
T10
What vertebral level is the opening for the aorta in the diaphragm
T12
What are the 3 main branches of the abdominal aorta that supply the gut and what vertebral level do they occur?
celiac trunk (T12), superior mesenteric artery (L1) and inferior mesenteric artery (L3)
What forms the IVC in the abdomen
hepatic portal vein
At what vertebral level does the aorta bifurcate?
L4
What artery supplies the foregut?
Celiac trunk
What artery supplies the midgut?
SMA
What artery supplies the hindgut?
IMA
What two veins from the portal vein?
splenic vein and the superior mesenteric vein
List 4 sites of portocaval anastomoses
In the distal oesophagus, retroperitoneal, rectal and paraumbilical
What is the clinical significance of these portocaval anastomose
portal hypertension causes dilation of these anastomotic veins
What is the sympathetic nerve supply to the abdominal viscera?
- Abdominopelvic splanchnic nerves (greater, lesser and least)
- prevertebral sympathetic ganglion
- abdominal aortic plexuses
What is the parasympathetic nerve supply to the abdominal viscera?
- anterior and posterior vagal trunks (vagus nerve - 10th cranial nerve)
- pelvic splanchnic nerves (S2, S3, S4)
What is the effect of sympathetic innervation on GI activity?
Increased GI secretion, increased peristalsis and GI motility and vasodilation of blood vessels
What is the effect of parasympathetic innervation on GI activity?
decreased GI secretion, decreased peristalsis and GI motility and vasoconstriction of blood vessels
What is the effect of a vagotomy on gastric secretion?
decreased gastric secretion
What is the difference between the greater, lesser and least splanchnic nerves and the pelvic splanchnic nerve
Greater, lesser and least splanchnic nerves have sympathetic innervation.
Pelvic splanchnic nerve has parasympathetic innervation.
What are splanchnic nerves?
Paired visceral nerves carrying fibers of the autonomic nervous system (visceral efferent fibers) as well as sensory fibers from the organs (visceral afferent fibers).
What is the chief difference in the arrangement of ganglia in the sympathetic and parasympathetic nervous system?
sympathetic preganglionic fibers tend to be shorter than parasympathetic fibers and sympathetic fibers tend to form more synapses than parasympathetic fibers.
The right kidney lies slightly at a lower level than the left kidney. What is the reason for this?
liver lies above the right kidney
What is the anterior to posterior arrangement of the structures entering and leaving the hilum of the kidney?
Renal vein, renal artery, ureter
How are the kidneys peritonised?
retroperitoneal
What type of gland is the adrenal gland?
endocrine gland
What is the anatomical location of the adrenal (suprarenal) glands?
superior to the kidney
What is the difference between exocrine and endocrine glands.
endocrine glands secrete into the blood whereas exocrine glands secrete into ducts.
What is the term used to describe the expanded upper part of the ureter
renal pelvis
What 3 locations do the ureter constrict?
pelviureteric junction, pelvic brim, vesicoureteric junction
How are the ureters peritonised?
retroperitoneal
What is the function of the portal vein?
Transport venous blood from the spleen, pancreas, gall bladder and abdominal part of the GI tract
How is the portal vein formed?
By the union of splenic vein with the superior mesenteric vein
Where is the portal vein located?
Behind the neck of pancreas (L 2 vertebral level)
What is the location of portocaval shunts
Anorectal junction, gastroesophageal junction and at the umbilicus
During portal hypertension what occurs at the portocaval shunts
Anorectal junction - hemorrhoids Gastroesophageal junction - esophageal varices
Umbilicus - caput medusa
What is the parasympathetic innervation of the abdominal organs?
Vagus nerve (CN X) and pelvic splanchnic nerves (S2, S3, & S4)
What is the sympathetic innervation of the abdominal organs?
abdominopelvic, splanchnic nerves (greater T5-T9, lesser T10-T11 and least T12)
prevertebral sympathetic ganglia
abdominal aortic plexus
