ch 19- The Cardiovascular System: Blood Vessels 2-4

Question 1

blood vessel walls the 3 layers

Answer 1

tunica intima, media, externa

Question 2

tunica intima

Answer 2

innermost layer of blood vessel, endothelium and simple squamous cells, provides slick surface to make blood flow easier by reducing friction and resistance

Question 3

capillaries have

Answer 3

only endothelium and basement membrane

Question 4

tunica media

Answer 4

middle layer of vessel wall, contains smooth muscle, thicker in arteries than veins, maintains BP and circulation. veins have thinner tunica media

Question 5

vasoconstriction

Answer 5

smooth muslce contracts, lumen smaller

Question 6

vasodilation

Answer 6

muscle relaxes, lumem larger

Question 7

lumen

Answer 7

general term for any empty space, smith travels through it

Question 8

tunica externa

Answer 8

outermost vessel wall, has collagen fibers, protects vessel, anchors blood vessels to structures, withstands stretch and prevents breaks

Question 9

vasa vasorum

Answer 9

larger vessels have this, blood vessel on a blood vessel. larger arteries have walls that are too thick and needs smaller ones for nutrients to enter

Question 10

arteries

Answer 10

branches several times to make smaller vessels. carry blood away from heart
systemic- oxygenated blood is carried
pulmonary arteries- oxygen poor blood

Question 11

elastic arteries/conducting arteries

Answer 11

pulmonary trunk and aorta branch with brachiocephalic, left carotid, left subclavian. conducts blood away with large lumen, making resistance less and blood conduction easier.

Question 12

elastic arteries have

Answer 12

a lot of elastin, walls can expand and recoil as heart pumps blood in, allowing for blood to flow smooth and relaxes heart

Question 13

muscular arteries

Answer 13

distributing arteries, branches off elastic arteries, good for vasoconstriction and dilation. thicker tunica media, less elastic quality but good for that

Question 14

arterioles

Answer 14

resistance arteries, smallest ones, flow into capillary beds directly. vasoconstriction and vasodilation controls how much blood goes into capillary bed. less blood is less blood in capillaries.

Question 15

capillaries

Answer 15

exchange vessels, directly contact tissue allowing for gas exchange and waste removal, squeeze thru single file bc they are so small. joined by tight junctions, but have intracellular clefts that help permeability

Question 16

intracellular clefts

Answer 16

small open spaces where fluids and smack solutes pass, these are not in brain capillaries bc they need to minimize movement of stuff.

Question 17

wall of capillary is simple squamous epithelia, how is that beneficial

Answer 17

increases the rate of exchange

Question 18

continuous capillaries

Answer 18

most common, least permeable, uninterrupted wall no extra holes or pores. water and ions pass, in skin and skeletal tissue

Question 19

fenestrated capillaries

Answer 19

walls have pores, more permeable, found where absorption and filtration are frequent. small intestine and kidneys. increases rate of exchange, larger things can pass through buy selective. no RBC or proteins

Question 20

sinusoid capillaries

Answer 20

least common, most permeable. large inrtracellular clefts and large lumen. giant pores holes and wider. WBC and RBC can pass through. ex liver bone marrow spleen

Question 21

microcirculation

Answer 21

flow of blood through capillary bed. artery to capillary bed to venule.

Question 22

terminal arteriole rich

Answer 22

branches to form network of capillaries. arteriole pressure controls blood flow. capillary bed empties into post capillary venule. rich red to o2 poor blue

Question 23

venules r

Answer 23

oxygen poor and nutrient poor, waste rich blood.

Question 24

veins

Answer 24

from capillary beds smaller veins combine to form larger beds. carry blood to heart
systemic- carry oxygen poor blood
pulmonary- oxygenated blood

Question 25

venule veins

Answer 25

lead from capillary bed to larger veins porous and easy passage to and from bloodstream. more permeable.

Question 26

veins

Answer 26

thinner tunics, larger lumen. less tissues in walls, larger lumen allows for more blood to be stored in blood reservoirs temporarily.

Question 27

why does low pressure in veins create an issue

Answer 27

can impair blood flow, blood could stop but balance is possible!

Question 28

physiology of circulation

Answer 28

blood flow, blood pressure, resistance

Question 29

blood flow

Answer 29

volume of blood flowing through a vessel, organ, or entire circulation in a period. flows high to low. if an organ doesn't need blood, vessels serving that organ constrict, then once blood needed, would dilate.

Question 30

hydrostatic pressure difference

Answer 30

must exist for blood flow to occur. drives blood flow force, arteries have higher pressure because more smooth muscle and tissue is there. example- equalizing that pressure of heart would stop blood flow in heart

Question 31

blood pressure

Answer 31

force exterted on blood vessel wall by blood it contains. like water balloon. blood pushes against it, highest pressure in aorta bc its closest to the heart and propels the furthest distance.

Question 32

how blood pressure changes as blood goes from artery to capillary to vein

Answer 32

pressure decreases along the way

Question 33

arterial blood pressure

Answer 33

indicator better than veins, doctors r concerned with this

Question 34

resistance

Answer 34

opposition of blood flow thru a vessel bc of friction between vessel wall and blood flowing. peripheral resistance is the highest in systemic circulation.

Question 35

3 reisstance sources

Answer 35

blood viscosity- more viscous nis more pressure bc of resistance in vessel vessel legnth- longer means more wall of vessel so more resistance exists vessel diameter- smaller diameter means greater resistance smaller tube blood in more contact so more resistance

Question 36

which factor of resistance can be changed

Answer 36

vessel diameter

Question 37

how do changes in blood pressure and resistance affect blood flow

Answer 37

hydrostatic pressure increases, blood flow increases resistance increases, blood flow decreases . more blood rubs vessel wall.

Question 38

systemic blood pressure

Answer 38

pumping action of heart generates blood flow, blood pressure results when blood flow is opposed by resistance of blood vessels.

Question 39

arterial blood pressure

Answer 39

blood pressure in aorta is pulsatile, rises and falls in fashion. affected by distensibility of vessel walls and by blood volume

Question 40

distensibility of blood vessel walls, degree of stretch of blood vessels

Answer 40

less elasticity means higher pressure

Question 41

volume of blood pumped into arteries

Answer 41

higher blood volume means more blood pressure

Question 42

systolic and diastolic

Answer 42

pressure of contraction, pressure when heart relaxes. when it relaxes, still need pressure to move blood.

Question 43

normal BP

Answer 43

90-120 over 70-80

Question 44

pulse pressure

Answer 44

systolic minus diastolic, normal is 40 Hg. represents force the heart generates with each contraction. higher pressure means heart is working harder to pump blood.

Question 45

capillary blood pressure

Answer 45

low blood pressure typically, important bc need low pressure bc walls bust open if not. steepest drop in pressure is in arterioles bc once it gets to capillary it wants that low pressure

Question 46

venous blood pressure

Answer 46

bp generally low, but low pressure in veins would prevent efficient blood return.

Question 47

how to solve venous BP that is low

Answer 47

skeletal muscle- contracts muscles to squeeze veins and push blood forward large diameter lumen- larger diameter is lower pressure blood flow easy sympathetic vasoconstriction- vessel wall constricts to push blood toward heart venous valves- appendages like arms and legs have many of these, they prevent blood from flow backwards.

Question 48

regulating blood pressure

Answer 48

maintenance of BP involves regulating cardiac output CO, peripheral resistance (R), and blood volume. increase CO, R blood volume increases blood pressure. CO up body changes resistance so BP decreases and stays normal level. CO factors affected- SV and HR