Flashcards in Lecture 13 - Alimentary 5 Deck (50):
Which three arteries supply the foregut, midgut and hindgut?
Coeliac trunk, SMA and IMA
Which two arteries overlap in their supply to the pancreas?
coeliac trunk (superior pancreaticoduodenal arteries) and SMA (inferior pancreaticoduodenal arteries)
What does the foregut consist of? (6)
Stomach, liver, gallbladder, pancreas, spleen and first + half of second part of the duodenum
Give for the foregut:
What group are the coeliac lymph nodes part of?
The preaortic nodes
What does the midgut consist of? (3)
Distal duodenum (below greater duodenal papilla)
Rest of the small intestine
Large intestine to approximately two thirds of the transverse colon
Give for the midgut:
What does the hindgut consist of?
Rest of the larger intestine to the upper rectum
Also lower rectum + anus
What are the lower rectum + anus mostly supplied by though
The internal iliac arter
Give for the hindgut:
Where do the sympathetic ganglia (coeliac, superior and inferior mesenteric) receive preganglionic fibres from?
Thoracic and lumbar splanchnic nerves
What are the sympathetic ganglia associated with?
The origins of the arteries of the same name
Give the for the foregut:
Coeliac ganglion (paired) - thoracic splanchnic
Give the for the midgut:
SMG - thoracic splanchnic
Give the for the hindgut:
IMG - lumbar splanchnic
What are the sensory fibres most sensitive to?
Stretch or distension/colic
What does sympathetic stimulation of the gut do?
Reduce motility and vasoconstrict
What does parasympathetic stimulation of the gut do>
Increase motility and secretion
What are the three branches of the coeliac trunk?
Splenic artery, left gastric artery and common hepatic artery
What are the 6 divisions of the SMA/
What are the parts of the gut supplied by branches of the SMA
What are the parts of the gut supplied by branches of the inferior mesenteric artery? (3)
What is the marginal artery?
An arterial arcade which runs parallel to the large and intestine and forms side to side anastomoses
What does the marginal artery anastomose with?
Branches of the SMA and IMA
Where does the marginal artery extend from?
The sigmoid branch of interior mesenteric artery to the ileocolic branch of the SMA
What does the marginal artery allow for?
Retrograde flow from the IMA to supply areas normally supplied by the SMA/coeliac trunk if they become blocked
Where does the IMV join the splenic vein
Behind the body of the pancreas
Where does the SMV join the splenic vein
Behind the head of the pancreas
What is the portal vein formed by
The confluence of splenic and SMV
What are the arteries that supply the rectum and anus (4)?
Superior rectal (Branch of IMA)
Middle rectal (Branch of internal iliac)
Inferior rectal (Branch of internal iliac)
Middle sacral artery (from bifucation of aorta into common iliac)
What is the collective name for all the interconnecting venous plexuses either within the wall or outside muscle of the rectum?
Rectal venous plexuses
Where does the internal rectal plexus drain into?
Where does the external rectal plexus drain into (3)
Middle internal iliac vein
Lower internal pudendal (tributary of the IIV)
What causes haemorrhoids
Dilation of the veins of the internal plexus
What does the lymph drainage of the rectum follow?
The arteries to the pre-aortic and internal iliac nodes.
Exception: lower anal canal to superficial inguinal nodes
All the lymph drainage of the rectum goes to the pre-aortic and internal iliac nodes true or false?
The innervation of the rectum is completely autonomic true or false?
False, in the lower anal canal it is somatic
Where does the sympathetic innervation of the rectum originate from?
Lumbar sympathetic trunk
Where does the parasympathetic innervation of the rectum originate from?
Pelvic splanchnics (S2-4)
What can the rectum sense?
Stretch above the pectinate line
Pain and temperature below
What supplies the pancreas? (3)
Superior + inferior pancreaticoduodenal arteries (head+uncinate process)
The splenic arteries anastomose with the superior and inferior pancreaticoduodenal arteries, true or false?
What is venous drainage of the pancreas?
Mostly splenic vein
Pancreaticoduodenal veins (head + uncinate process)
What is the lymph drainage of the pancreas like?
Pancreatic lymph nodes and vessels located along the splenic artery and its branches. Drain into the coeliac nodes
What is the nervous supply of the pancreas like?
Parasympathetic - vagal
Sympathetic - thoracic splanchnic
How does blood enter the liver?
Into the hilus via left and right branches of the hepatic artery and portal vein.
What else travels with the arteries into the hilum?
A plexus of sympathetic and parasympathetic nerves derived from the coeliac plexus
What do both sets of vessels branch and branches travel together through?
Portal canals, portal areas or portal 'triads' along with:
bile duct and lymph vessels
Where do the sinusoids run in the liver?
From the outside of the lobules to central veins
How do the central veins of the liver eventually drain?
They anastomose to form larger veins (usually 3 larger upper and several smaller veins