9 29 Anatomy of the GI Tract-Table 2 Flashcards
Why do we have the celiac trunck, superior mesenteric and inferior mesenteric trunk arteries?
to give ample blood suply to the GI tract!
what does the celiac trunk supply?
supplies the forgut organs
what are the foregut organs
distal esophagus, stomach, proximal duodenum, liver, gallbladder, pancreas, spleen.
what does the superior mesenteric artery supply?
the midgut
where does the celiac trunk arise?
from the abdominal aorta, it is the first unpaired vessel that arises right at the bottom of the diaphram
what are the branches of the main celiac trunk?
Left gastric artery; splenic artery; common hepatic artery.
where does the left gastric artery course?
on the lesser curvature of the stomach on the left side, comes right off the top of the celiac trunk
how are the left and righ gastric arteries related
they are kissing cousins :-) they form an anastimosis aound the middle of the lesser curvature of the stomach. They also both course through the lesser omentum!
where does the splenic artery go?
it arises from the left of the celiac trunk and go to the spleen and sends off pancreatic arteries and also send the left gastroomental artery to the greater curvature of the stomach through the greater omentum. Lastly it also gives the short gastric arteris that go to the top of the stomach.
where does the common hepatic artery arise and go?
it comes from the right of the celiac trunk and goes to bifurcate at the liver into the hepatic artery proper that will give rise to the left and right hepatic arteries to the left and right lobes and the cystic artery to the gallbladder. The common hepatic artery will also give rise to: right gastric artery on the lesser curve of the stomach. and to the gastro-duondanal artery to the greater curvature of the stomach wich also gives rise to the pancreatiiocoduodenal artery that goes off of the gastroduodenal artery to the pancreus.
what is the supeior mesentaric artery connection to the celiac trunk?
through an anastimosis with the superior mesentaric artery and the pancreatiocoduodenal artery! (superior and inferior pancreaticoduodenal arteries )
What does the superior mesenteric artery supply?
it supplies the midgut organs
what are the midgut organs?
pancreaus and disdal duodenum; jejunum; illium; cecum and appendix, ascending colon, transverse colon.
what ar the branches of hte SMA?
- trunck; 2. inferior pancreaticoduodenal artery; 3. the jejunal and ileal arteries. 4. ileocolic artery. 5. the right colic artery 6. the middle colic artery
what does the inferior pancreaticoduodenal artery supply?
the anastimotic connectin to the pancreus and the supperior pancreaticoduodenum artery.
what do the jejunal and ileal arteries supply
they supply through the mesentary to the jejunum and the ileal.
what does the ileocolic artery supply?
the ilium and the colon and the apendix
what does the right colic artery supply?
the ascending colon.
what does the middle colic artery supply?
the first half of the transverse colon.
where does the midgut end?
at the mid point or so of the transverse colon where the SMA blood supply ends.
What does the The inferior mesenteric artery (IMA) supply?
the Hind gut organs.
What are the hind gut organs?
Distal part of the Transverse colon; sigmoid colon; rectum.
What are the parts of the IMA
- Left colic artery 2.The sigmoidal arteries 3. Superior rectal artery
what does the left colic artery supply?
the distal of the transverse colon, and the descending colon.
what does the sigmoidal arteries supply?
The sigmoidal section of the colon.
What does the superior rectal artery supply?
The rectum and the upper part of the anus.
What are the anastomosis of the mesenteric?
the superior mesenteric artery, and the inferior mesenteric artery are connected by the marginal artery of Drummond that goes all around the border of the colon
what is the outline of the hepatic portal system?
heart to arteries to arteriores to capillary #1 (lamina propria) then to venules then to venus (hepatic portal system of veins) then venules again and to capillary bed #2 (hepatic sinusoids) then venules (terminal hepatic venule) then to veins and finally to the heart!
what does the portal vein collect?
the gi visceral blood from the foregut midgut and hind gut
what are the veins of the foregut?
the left and right gastric veins (above the stomach); the gastroomental (below the stomach); spenic vein(from the spleen and the pancreus)
what are the veins of the midgut?
the superior mesenteric vein!
what are the parts of the superior mesenteric veins?
they have the same divisions as the mesenteric arteries.
What are the veins of the hindgut?
the inferior mesenteric vein that goes to the splenic and to the portal
what are the parts of the inferior mesenteri vein?
the same as the artery system
what about the direction of blood flow in the hepatic portal system?
there are no valves! so blood in any direction
where are the portal caval anastomoses?
there are 3 places where blood drains form both the hepatic portal system and the caval veins: the esophagus, the rectum, and the superficial abdomen
esophagus portal drainage
left gastric vein to the HPV to the liver and so on
esophagus caval drainage
through the esophageal vein to the azygos veins to the SVC
what happens if there is congestion in the portal vein?
well then blood flows backwards and can go back to the distal esophagus and then back up through to the azygous system of veins?
what would happen to the esophageal veins if there is a block in the portal vein?
esophageal varices where they can burst and bleed fast and critically!
rectum portal drainage
superior rectal vein, inf. mesenteric vein, splenic vein, HPV
what about caval dreainage of the rectum?
middle and inferior rectal veins, internal iliac vein, common iliac vein, IVC
Where is the anastimosis of the rectal drainage?
At the rectum itself
what happens if congestion in the portal to the rectal drainage?
the blood would get pushed to the rectal veins and get internal hemeroids and vericois veins at the rectum.
what is the caval drainage of the ant abdominal wall?
superficial epigastric veins, femoral vein, external iliac vein, common iliac vein and IVC
What is the portal drainage of the abdominal wall (campers fascia)
periumbilical veins to the hepatic portal vein
what happens if the portal veins is blocked in the abdominal wall?
Caput medusa, where the veins in the abdominal wall dialate and look like snakes
What are the three porto-caval anastomoses?
- distal esophagus 2. rectum 3. umbilicus or “gut” “Butt” “Caput”
What does the sympathetics do to the GI tract
cause the liver to release glucose to the blood; relax the galbladder; and Decrease parastallisis in the stomach and the small and large intestines. but it will increase blood flow to that area.
what does sympathetics do to the penis
cause ejactulation
where do the sympathetics come from in the GI region?
from the pre-aortic gaglion
what are the names of the pre-aortic gaglions?
the celiac; supeior mesenteric; aortocorenal; Inferior mesenteric; superior hypogastric; hypogastric; inferior hypogastric
where do the post gangleonic nerves course from the pre-aortic gangleon?
they course along the arteries
how do I know where sypathetic inervation comes from?
the more proximal the GI tract, the higher in the pre-aortic gangleon the inervation comes from
where do the sypathetics come form to innervate the pre-arotic gangleon?
From the T1 to L2 spinal cord levels. The nerve comes out the the lateral horn to the entral root to the ventral ramus then the right ramus to the splacnic nerve.
where does the greater splacnic come from and go to?
from the T50T9 level and to the celiac gangion!
the lesser splancnic to from where?
the T10,T11 to the superior mesenteric gangleon!
what about the penus sympathetic?
L2 to the preaortic gangleon
Visceral sensory
this is along the sympathetic at every level. It goes in the dorsal root.
where does all sensory viseral info go?
to the dorsal root gangleon. and to the dorsal horn gray matter.
what are the sympathetic nervous system neurotransmitters?
Pre-gangleonic: Acetyl choline that binds to Cholinergic receptors; post gangleonic release neuroepinephrin or epinephrin that binds to adrenergic receptor (adreniline)
adrenal gland exception in the sympathetic system
does not have a post ganglionic neuron it comes from the T12 or some L1 or L2 level and goes through the least splancnic and through the pre-aortic and doesn’t synapse! the adrenal medula itself then releases the epinephern/neuroepinephrin !
Sweat glands sympathetic exception
uses Ach as the post gangleonic neurotransmitter
what does the parasympathetic innervation do to the GI
Stomach/GI tract will increase digestion, and the parastalysis; gallbladder will contract, and penis will erect.
where do they come from (parasympathetic)
The intermural gangleon cause the innervation, and the nerves to the intermural come through the pre-aortic gangleon but don’t synapse and originate from the brain stem, and the s2-s4 region. (comes down through the vegas nerve). then follow the arteries out to the intermural nerons.
what transmitters do we use in the parasympathetic?
use Acetly Choline and Cholinergic receptor in both the pre and post gangleonic synapse.
pelvic splancnic is wierd…why?
it is parasympathetic splancnic (the only parasympathetic splancnic). They innervate Hind gut
what does the vegas nerve innervate?
Parasympathetic for the fore gut and mid gut.
what are the nicotinic and muscartinic receptors
two types of cholinergic receptors.
What supplies the foregut
Celiac Trunk
What supplies the Midgut (the jejunum and the ileum)
The superior mesenteric artery
what supplies the hindgut
the inferior Mesenteric artery
what drains the foregut.
The portal vein
what drains the midgut
The superior mesenteric veins
what drains the hind gut?
The inferior mesenteric veins
where is the right gastroepiploic artery
in the greater omentum
where is the anastimosis of the right gastroepiploic artery?
it anastimosis with the left gastroepiploic artery
what is found in the hepatoduodenal ligament?
the hepatic artery proper, the common bile duct, the portal vein
what type of tissue is the lesser oomentum
it is mesentary made of mesothelium that is part of the paratinium.
what cells make bile
the hepatocytes
what are the vessels that cross the 3rd part of the duodenum?
the Superior mesenteric artery and vein.
what is the artery surrounds the colon?
the right, middle, and left colic arteries.
where is the capillary bed #1 in the intestines?
the lamina propria
how do we get from the portal system to the IVC?
the Portal veins to the hepatic sinusoids that percilate through the hepatocytes and then to the hepatic venules to the hepatic veins to the IVC!
where do all sympathetic inervation arise?
T1 - L2
where does parasympathetic arise?
brains stem; and for the hind gut and below S2-S4
