Ch.21 - The Circulatory System

Question 1

which vessels have thicker walls?

Answer 1

arteries

Question 2

T/F: veins have valves

Answer 2

True, some do

Question 3

where does gas exchange occur?

Answer 3

in capillary beds

Question 4

what makes up capillary walls?

Answer 4

simple squamous epithelium (endothelium)

Question 5

purpose of vasa vasorum

Answer 5

provides O2 to walls of larger vessels

Question 6

T/F: arteries have valves

Answer 6

False

Question 7

location of vasa vasorum

Answer 7

outer layer of vessels

Question 8

pathway of blood flow

Answer 8

arteries, arterioles, capillaries, venules, veins

Question 9

difference btw capillaries in arteries and veins

Answer 9

arterial capillaries are not spaced out, don’t have pores (space btw endothelial cells) like vein capillaries

Question 10

which is deeper, veins or arteries?

Answer 10

arteries

Question 11

what are arterioles?

Answer 11

connect arteries to capillaries, where pressure drop occurs

Question 12

what is tunica media?

Answer 12

has smooth muscle that causes vasoconstriction, and relaxes for vasodilation, highly innervated (lots of nerves)

Question 13

what is vascular tone?

Answer 13

degree of constriction of blood vessel, constrictor influences + dilator influences

Question 14

what vessels do we have most control over?

Answer 14

arterioles

Question 15

what are intrinsic factors?

Answer 15

local affects, constriction/dilation, hypoxia

Question 16

what are extrinsic factors?

Answer 16

systemic/whole body affects, hormones, sympathetic innervation

Question 17

difference btw capillaries in CNS and non-CNS

Answer 17

capillaries in CNS have tight junctions, do not have openings (blood-brain barrier)

Question 18

what does ubiquitous mean

Answer 18

everywhere

Question 19

function of capillaries

Answer 19

site of diffusion btw blood and interstitial fluid, gas exchange

Question 20

what must you have in order to have blood-brain barrier

Answer 20

tight junctions in epithelial cells, preventing things from entering/exiting

Question 21

describe capillary beds

Answer 21

tissues requiring large amt of O2 & blood (highly vascularized), some are avascular (cartilage, cornea of eye, lens, epithelia)

Question 22

what tissues are avascular

Answer 22

cartilage, cornea of eye, lens of eye, epithelia

Question 23

are ligaments and tendons vascular or avascular

Answer 23

slightly vascular

Question 24

how does your body react to when you are hot?

Answer 24

superficial vascular plexus dilates to release excess heat

Question 25

what is venous return

Answer 25

blood going back to heart

Question 26

describe muscular pump

Answer 26

runs through skeletal muscle, contraction and relaxation of skeletal muscles surrounding deep veins to push blood upwards

Question 27

describe respiratory pump

Answer 27

pressure changes in ventral body cavity during breathing, moves blood up towards heart.

Question 28

what influences respiratory pump

Answer 28

increases abdominal pressure, decreases thoracic pressure

Question 29

what does diaphragm do when you inhale

Answer 29

drops to increase abdominal pressure

Question 30

what is venous reserve?

Answer 30

amount of blood stored while we are at rest

Question 31

where can we find venous reserve?

Answer 31

in systemic veins & venuoles of abdominal organs (liver & spleen) and veins of the skin

Question 32

how to access venous reserve?

Answer 32

spleen contracts to push blood out @ time of hemorrhage

Question 33

what is circulatory pressure

Answer 33

pressure difference btw base of ascending aorta and entrance to R atrium

Question 34

what is blood pressure

Answer 34

arterial pressure, pressure in systemic arterial circuit, bc arteries are where you feel your pulse to check blood pressure

Question 35

what is capillary hydrostatic pressure?

Answer 35

pressure in capillary beds thats pushing stuff outside (declines along length of capillary)

Question 36

what is venous pressure

Answer 36

pressure in veins (very low)

Question 37

formula for stroke volume

Answer 37

end diastolic volume - end systolic volume

Question 38

what is pulse pressure

Answer 38

rise in aortic pressure from systolic to diastolic | systolic pressure - diastolic pressure

Question 39

what is bulk flow?

Answer 39

inc in pressure (systolic) is followed by dec in pressure (diastolic) (blood flow in cardiovascular system)

Question 40

formula for blood flow

Answer 40

change in pressure divided by resistance

Question 41

what are sources of resistance?

Answer 41

blood viscosity, blood vessel length, blood vessel diameter

Question 42

what does viscosity mean

Answer 42

state of being thick

Question 43

what conditions affect blood viscosity

Answer 43

anemia or polycythemia

Question 44

how does blood vessel length affect resistance

Answer 44

the longer the vessel, the more resistant

Question 45

how does vessel diameter affect resistance

Answer 45

bigger the vessel, the less resistance

Question 46

which source of resistance can be changes the quickest? where? why?

Answer 46

vessel diameter. arterioles. bc we have the most control of vascular tone

Question 47

in what vessel does the steepest drop in blood pressure happen? why?

Answer 47

arterioles, bc they have the most resistance

Question 48

what happens to blood vessel when volume increases?

Answer 48

walls expand to accommodate

Question 49

where is blood flow the slowest? why?

Answer 49

in capillaries. bc this is site of gas exchange

Question 50

describe inverse relationship btw blood flow velocity and cross-sectional area

Answer 50

inc in area = dec in velocity of flow, dec in area = inc in flow. if theres more area for blood to flow through, it takes more time to pass

Question 51

how do extrinsic factors affect blood flow

Answer 51

generally set the tone of blood flow

Question 52

how to intrinsic (local) factors affect blood flow

Answer 52

respond immediately to demands of tissue

Question 53

where does "local vasodilation" occur?

Answer 53

arterioles bc we have most control over them

Question 54

why is there a pressure drop in arterioles?

Answer 54

bc they have to drain blood into capillaries which have much smaller area