Blood Vessels and Circulation - Mace Flashcards
The tunica intima of an artery or vein consists of what two layers?
Endothelium and subendothelial layers
What comprises the tunica media of a blood vessel? Is the tunica media thicker in an artery or vein?
It consists of smooth muscle. It is thicker in arteries than veins
Are valves present in veins, arteries, or both?
Veins only
What is the significance of the tunica externa?
The tunica externa has tiny blood vessels that supply the tunica media with blood.
What are the 3 types of arteries? Give an example of each.
Elastic arteries - allow “balloon” effect. Ex: aorta, subclavian, common illiac
Muscular arteries - distribute blood to specific organs. Ex: femoral artery, splenic artery
Arteriole - the small arteries just before capillary beds.
Do arteries or veins have a thicker tunica externa?
Veins
There are 3 types of capillaries, what are they?
Continuous, fenestrated, and sinusoid
What type are the majority of capillaries in the body?
Continuous capillaries
What molecules can pass though a continuous capillary?
Blood gasses and H2O for the most part
What makes fenestrated capillaries different from continuous capillaries? Where are they located?
Fenestrated capillaries have tiny holes in the membrane (called fenestrations) that aid in absorption and secretion. They are located in exocrine glands and kidneys
What makes a sinusoid capillary different from other capillaries? Where are they found?
Sinusoid capillaries have large openings and a discontinuous basement membrane. It allows for large molecules and whole cells to pass through. They are located in the liver, spleen, and red bone marrow.
What structures control blood flow through the capillary bed?
Precapillary sphincters
What are arterial anastomoses? Where might you find them?
They are alternative pathways for blood to reach a target. One place they are found is the brain, in an effort to maintain perfusion if something goes wrong.
What are venous anastomoses?
Pathways of alternative drainage of blood.
What is a shunt?
A shunt is an anastomosis between an artery and a vein. The blood does not go through a capillary bed to reach to venous system.