3A Flashcards
The thoracic aorta and abdominal aorta are both part of what segment of aorta?
Descending aorta
What makes the aortic wall highly distensible?
A large amount of elastic tissue within the aortic wall
Blood pressure is at its highest in what part of the aorta?
ascending aorta
What is the Windkessel effect?
The expanding and recoiling of the aorta - it accepts blood and pushes it forward - thereby making the pulsatile flow smoother and streamlined
What are the three layers of a typical artery?
Tunica intima, tunica media, tunica externa
What is in the tunica media?
Elastic tissue and smooth muscle
Are arteries involved in the exchange of gas?
No, the wall is too thick for oxygen or CO2 to diffuse thru that thick of a layer of tissue
Where is the site of greatest resistance and largest pressure drop in circulation?
In arterioles (which are basically smaller arteries)
What is the effect of arterial vasoconstriction?
Increased resistance and decreased blood flow thru the vessel lumen
What can induce a change in the radius of an artery or arteriole?
Autonomic nervous system, circulating hormones (angiotensin II, and vasopressin), Local vasoactive substances, and other things like temperature
Which is the thinnest of all of our blood vessels?
Capillaries
What is the only layer that capillaries have?
Tunica intima - endothelial cells and basal lamina
Do capillaries dilate or constrict?
No, they have no smooth muscle
Which blood vessels have the greatest total cross-sectional and surface area?
Capillaries
Do all veins and venules have valves?
No, only some do
What is the largest vein in the body?
Inferior vena cava
What does the celiac trunk (artery) supply?
Liver, gall bladder, stomach, spleen, pancreas and duodenum
What does the superior mesenteric supply?
Small intestine and large intestine (colon)
What does the inferior mesenteric supply?
Large intestine and rectum
Where does the hepatic portal vein directly feed into?
Liver
Where this the hepatic portal system collecting blood from?
mainly from all of the abdominal organs - large intestine, small intestine, spleen, pancreas
What organ is the first to see all of the nutrients that we have ingested and absorbed?
Liver
Where does all of the blood that leaves the liver drain?
Inferior vena cava
