Blood Vessels

Front 1

Endothelium

Back 1

The Lining of Blood Vessels, very smooth

Front 2

Vasoconstriction

Back 2

The contraction of smooth muscle in arteries that reduces their diameter, which reduces blood flow and raises blood pressure.

Front 3

Vasodilation

Back 3

The relaxation of smooth muscle in the arteries that increases their diameter, which increases blood flow and lowers blood pressure

Front 4

arteries, capillaries, veins

know the structural differences between them

size of lumen

thickness of wall

which have many elastic fibers?

amount of smooth muscle

Back 4

Veins have larger lumens, no elastic fibers, no smooth muscle, minimal vasoconstriction and vasodilation. Arteries have a thick layer of smooth muscle called the tunica media and a huge number of elastic fibers. capillaries are one red blood cell in diameter.

Front 5

Remember, there is little parasympathetic innervation of ___, and most arteries have a low-level constant (24/7) ___ stimulation.

Back 5

arteries, sympathetic

Front 6

ii)Also, to make it a bit more complicated, remember that some arteries have ___ receptors and some have ___ receptors (and some have both!)

Back 6

α-, β2-

Front 7

Alpha stimulation causes arteries to

Back 7

constrict

Front 8

Beta 2 stimulation causes arteries to

Back 8

relax

Front 9

Effect of an increase or decrease in diameter of arteries on blood flow? Numerically, how much is blood flow affected?

Back 9

Blood flow is proportional to the fourth power of radius.

Front 10

describe the 3 types of capillary walls

Back 10

continuous - intercellular clefts are gaps between neighboring cells. Most capillaries are continuous.

fenestrated - plasma membranes have many holes that allow large volumes to filter out or be absorbed in. These caps are found in the small

sinusoid - have very large fenestrations. they are found in bone marrow, the liver, the spleen, and some hormone-secreting glands.

Front 11

differentiate between filtration and absorption

Back 11

Filtration is when fluid moves from plasma into interstitial fluid.

Absorption is when fluid moves from the interstitial fluid across the cap membrane into the plasma.

Front 12

​what substances leave plasma in capillaries to enter tissues?

​What leaves tissues to enter capillaries?

Back 12

Glucose, amino acids, electrolytes, and water.

Front 13

what factors help blood flow uphill in veins, especially leg veins?

Back 13

Leg muscles push on veins, which pushes blood up. Valves keep the blood from falling back down.

Front 14

capillary exchange: substances move ____ a concentration gradient. This process is called ___

Back 14

down, passive diffusion (this is somewhat restricted in brain capillaries)

Front 15

Capillary exchange: water soluble substances diffuse through intercellular ___ or ___

Back 15

clefts or fenestrations

Front 16

capillary exchange: diffusion results in ___ and ___ of substances.

Back 16

filtration and reabsorption