Vessels Flashcards
What are anatomical end arteries?
Vessels whose terminal branches do not anatomies.
Brain, kidneys, spleen
What are functional end arteries?
When anastomoses are so small that arteries may be considered end arteries (ex: coronary arteries)
Which tend to anastomose more? Arteries or Veins?
Veins
What is the tunica intima made up of?
A layer of simple squamous epithelium, called endothelium
What is the tunica media composed of?
Circularly arranged layers of smooth muscle cells under autonomic control
Vasoconstriction vs. Vasodilation. And what system controls each?
Vasoconstriction - narrowing of vessel (sympathetic)
Vasodilation - widening (parasympathetic)
Remember - Thanksgiving dinner - parasympathetics will dilate vessels to “rest and digest”
What are the differences between the tunicas for arteries and veins?
Arteries have a thicker tunica media and veins have a thicker tunica externa
What stops the blood in the vein from flowing back?
The tunica intima of the vein has valves that stop backward flow
What layers do capillaries have?
They have a basement membrane and an endothelium(lumen), so only 2 layers
What is the vasa vasorum?
It is the blood supply to the vessel itself. On the tunica externa
What is the difference between elastic and muscular arteries?
Has to do with the thickness of the wall relative to the size of the diameter of the lumen
What is occlusion?
The blockage or closing of a blood vessel or hollow organ
Basic kinds of capillaries?
Continuous capillaries
Fenestrated capillaries
Sinusoids or discontinuous capillaries
Varicose Veins
Dilated, tortuous veins. Valves are nonfunctional causing blood to pool. Caused by genetics, aging, stress, etc
Sclerotherapy
Irritant injected into smaller veins to cause scarring and closure of varicose veins
