Flashcards in Lecture 14 DA Deck (69):
What are the arteries found in the midline vascular plane?
Superior and inferior mesenteric arteries
They are single arteries that come off the aorta at the midline.
What are the arteries found in the lateral paired vascular plane?
They come off on either side of the aorta.
Where does the inferior suprarenal artery come off?
It comes off of the renal artery.
What artery supplies the diaphragm bilaterally, and where does it come from?
Inferior phrenic, comes off the aorta below the diaphragm, then travels superiorly to supply it.
Where does the superior suprarenal artery come from?
The inferior phrenic artery.
Where does the middle suprarenal artery come from?
Direct off the aorta.
What supplies the foregut?
What supplies the midgut?
Superior mesenteric artery.
What supplies the hindgut?
Inferior mesenteric artery.
What lies in the foregut?
Inferior oesophagus, entire stomach, pancreas, and proximal duodenum until the major papilla.
What lies in the midgut?
Distal duodenum, post major papilla, jejunum, and ilium, caecum and appendix, ascending colon, most of the transverse colon, up to the splenic flexure.
What lies in the hindgut?
Splenic flexure and onward to the anal canal.
Where on the aorta does the celiac trunk branch off?
Just below the aortic hiatus.
Where does the left gastric artery supply, and where does it branch off of?
It is one of 3 branches of the celiac trunk, and goes to the lesser curvature, distal oesophagus. It is the shortest branch of the celiac trunk.
Where does the splenic artery supply, and where does it branch off of?
It is one of 3 branches of the celiac trunk, and goes to the spleen, travelling along the posterior face of the pancreas, supplying it. Goes to the gastrosplenic ligament, and supplies the spleen, then goes to the greater curvature, and gives off the left gastro-omental artery, which anastamoses with the right one. Gives off short gastric arteries superiorly. Longest and biggest branch of the celiac trunk.
Where does the common hepatic artery supply, and where does it branch off of?
It is one of 3 branches of the celiac trunk. Divides into 2 branches. One is the proper hepatic artery, which travels along the free edge of the lesser omentum, and enters the porta hepatis, and splits into left/right hepatic arteries.
The second branch of the common hepatic artery is the gastroduodenal artery, which gives off the right gastro-omental artery, as well as branches to the pancreas head, proximal duodenum, called pancreatic/duodenal branches.
Where does the right gastric artery come from, and where does it supply?
It comes off the proper hepatic artery, sometimes the common hepatic artery. It supplies the lesser curvature, and anastamoses with the left gastric artery.
What level does the celiac trunk come off at?
Proximal end of L1.
What level does the superior mesenteric artery come off at?
Distal end of L1.
Which artery do the pancreatic and duodenal arteries anastamose with?
Superior mesenteric artery.
What does the ileocaelal artery supply?
Caecum and appendix.
What supplies the appendix, and where does it come from?
Appendicular artery, which is the ileocaecal artery after it enters the mesoappendix.
What supplies the ascending colon?
Right colic artery.
What does the middle colic artery supply?
What are arcades, and which arteries have them?
They are honeycomb-like arteries close to the main artery, jejunal and ileal. They give off vasa recta, which are tall and column-like.
What are vasa recta?
They are tall column-like arteries that come off of arcades in jejunal and ileal arteries.
Where are arcades more dense? What about vasa recta?
Arcades are denser in the ileum, and vasa recta are smaller.
In the jejunum, vasa recta are longer and more pronounced, with fewer arcades.
What does the middle colic artery anastamose with?
Inferior mesenteric artery.
What level does the inferior mesenteric artery come off at?
Which side of thr aorta does the inferior mesenteric artery come off at?
More on the left side of the abdominal aorta.
What is the main branch of the inferior mesenteric artery, and what does it supply?
The left colic artery, supplying the descending colon.
What do the left and right colic arteries travel through?
What are the branches of the inferior mesenteric artery aside from left colic artery?
Other branches are the sigmoidal artery, and superior rectal artery.
Where do the middle and inferior rectal arteries come from?
The middle comes from the internal iliac artery and the inferior comes from the pudental artery.
All three rectal arteries anastamose. End arteries are found here.
What is clinically significant about regions of the intestines being end organs?
They can be ressected and seperated without affecting supply of other parts.
Does the IVC make contact with the azygous system or the SVC?
It makes contact with both through the anterior abdominal wall.
What forms the IVC?
Left and right common iliac veins.
What forms the azygous system?
Ascending lumbar veins drain into the common iliac vein, meet with lumbar and subcostal veins as they do so, the three form the azygous system.
What is the difference between the right and left renal veins?
Right renal vein drains the right kidney, while left also drains the left gonad and left adrenal gland.
Where do the right suprarenal and right gonadal vein drain?
Direct to the IVC, with right suprarenal superior to the right gonadal vein.
Which vein drains most superiorly to the IVC?
The most superior is the hepatic vein, with the inferior phrenic just below it.
Which vein drains inferior to the renal veins on the IVC?
What is the portal system formed by?
The union of the splenic, superior, and inferior mesenteric veins to form the hepatic portal vein. Paraumbilical vein also drains to the portal vein.
What is the purpose of the portal system?
Provides drainage of the abdominal viscera to the liver, into hepatic sinusoids, pooled bodies in the liver, and carries digested nutrients, provides hormonal secretion from the pancreas and nutrient exchange takes place. The rest goes to the systemic venous drainage.
Do veins within the abdomen have valves?
Veins that lie in the trunk do not have valves, such as the IVC or portal system, so blood can flow in either direction.
What happens if one system of venous drainage in the abdomen is blocked (portal or systemic)?
If one is blocked, it will backflow in the other direction.
What happens if hepatic sinusoids are blocked (cirrhosis)? Which ends are most clinically significant?
Backflow to the systemic veins occurs, and they dilate. They are called varicosities. One at the most proximal and/or distal end are most significant clinically, dilation from blockage can cause a massive haemorrhage (theres no wmds in there, i promise), same with the anus/rectum.
What is caput medusa?
Umbilical vein is degenerate after birth, the paraumbilical vein surrounds it, connecting the portal system to the epigastric veins. If portal system is blocked, it can get distended, and is visible externally. Looks like the head of medusa, so its called caput medusa.
Where does the anterior and posterior abdominal wall lymph drain to?
To the axillary and inguinal lymph nodes.
What are lacteoles?
Found in the GIT, they are lymph tissue that lie within viscera.
Are there deep lymph nodes in the abdomen?
No, there are para-aortic lymph nodes, found on either side of the aorta, and pick up lymph from either side.
Where are pre-vertebral lymph nodes found?
They are at the midline, along the aorta.
Does abdominal lymph drain to the portal system?
No, they follow the arteries to systemic circulation.
What are the nodes of the celiac trunk, superior and inferior mesenteric arteries?
Superior and inferior mesenteric nodes..
Where does lymph from abdominal viscera drain to?
First to the cisterna chyli, then to the thoracic duct, then to the left brachiocephalic vein.
What is the clinical significance of lymph nodes that lie against the aorta?
They are very deep, so in the case of cancer, they can't be palpated. To work around this, the supraclavicular nodes are palpated as the aortic nodes drain to them. They are known as last sentinel lymph nodes. They are checked in suspicion of cancer.
What is the GIT innervated by?
The visceral nervous system, autonomic.
Sympathetic and parasympathetic are apart of the visceral efferent system.
Visceral afferent system is sensory.
What effect does sympathetic innervation have on the GIT?
It reduces blood flow to the GIT, directing it to the skeletal system. It also inhibits peristalsis, and digestion.
What is digestion stimulated by?
What is a consequence of peristalsis?
Slowed heart rate.
Which spinal nerves composes sympathetic innervation to the GIT?
Thoracolumbar outflow, from T6-T12.
Which spinal nerves composes parasympathetic innervation to the GIT?
Craniosacral outflow, from S2-S4
Are pre-synaptic fibres sympathetic or parasympathetic? How do they get to the aorta?
Sympathetic. They dont synapse with the sympathetic trunk, but travel along it, meeting with ganglion on the aorta, called pre-aortic.
How do post-synaptic fibres travel?
They are sympathetic, and travel through nerve plexi.
What forms the anterior and posterior vagal trunks?
Anterior is formed by the left vagus nerve, while posterior is formed by the right vagus nerve.
Do parasympathetic nerves form synapses with ganglia?
No, they do not. They go direct to the viscera, ganglia exist on or next to the viscera.
What are the foregut, midgut, and hindgut parasympathetic innervation from?
Foregut and midgut comes from vagus nerve, but hindgut comes from splachnic nerves.
Which spinal nerves do postganglionic fibres originate from for foregut, midgut and hindgut?
Foregut - T6-9.
Midgut - T8-12.
Hindgut - T12-L2.