blood vessels chp 21

Question 1

how many layers do both arteries and veins have

Answer 1

3 layers
1. tunica intima (tunica interna)

2. tunica media
3. tunica externa (tunica adventitia)

Question 2

tunica intima (tunica interna)

Answer 2

innermost layer with endothelial cell lining with underlying CT layer

Question 3

tunica media

Answer 3

middle layer made of concentric sheets of smooth muscle, encircling blood vessels

Question 4

tunica externa (tunica adventitia)

Answer 4

outermost layer
CT sheath with collagen and elastic fibers

Question 5

arteries structure

Answer 5

round with a thick wall
- tunica intima has internal elastic membrane so they can expand (veins dont)

• tunica media is much thicker in arteries with elastic fibers

-tunica externa is similar in arterties and veins

Question 6

vein structur

Answer 6

flattened / collapsed with thin wall

• tunica media is much thinner and has collagen

-tunica externa is similar in arterties and veins

Question 7

what are the 3 types of capillaries and what does a regular capillary consist of

Answer 7

consists of a basement membrane (basal laminate) and 1 cell layer thick endothelium

1. continuous capillaries
2. fenestrated capillaries
3. sinusoid capillaries

Question 8

continuous capillaries

Answer 8

endothelium form complete lining

-least permeable / restricted and regulated
- most common
- skin/muscle

Question 9

fenestrated capillaries

Answer 9

allows for rapid exchange of water and solutes

• pores/windows in endothelial lining
• in active areas of absorption / filtration
• in the kidney and small intestine

Question 10

sinusoid capillaries

Answer 10

most permeable
- free exchange of water and large solutes
- in special locations such as liver, bone marrow, and spleen

Question 11

where do capillaries function in

Answer 11

in interconnected networks (beds) inbetween arteries and veins

Question 12

collateral arteries allow for

Answer 12

capillary beds to receive blood from more than 1 artery

Question 13

a single arteriole gives rise to dozens of capillaries by way of

Answer 13

met arterioles

Question 14

thoroughfare channels are where ____ flows into capillaries with a ____

Answer 14

blood flows into capillaries with a precapillary sphincter

Question 15

capillary hydrostatic pressure (CHP)

Answer 15

blood pressure within capillary beds
- drives force for filtration
-pushes water and molecules out of bloodstream and into interstitial fluid

Question 16

filtration allows for ___ solutes to cross endothelium and ___ ones do not

Answer 16

small solutes ; larger ones do not

Question 17

what determines net filtration pressure (NFP)

Answer 17

CHP - BCOP

(capillary hydrostatic pressure - blood colloid osomotic pressure)

Question 18

high BCOP and low CHP leads to

Answer 18

reabsorption

• fluid movesinto capillary

Question 19

low BCOP and high CHP

Answer 19

filtration

• fluid is forced out of capillary

Question 20

NFP = 0 means

Answer 20

no net movement of fluid
CHP = BCOP

Question 21

blood pressure

Answer 21

force that blood exerts against a vessel wall

Question 22

systolic pressure

Answer 22

peak arterial pressure during ventricular contraction

Question 23

diastolic pressure

Answer 23

minimum arterial pressure during ventricular relaxation (between beats)

Question 24

pulse pressure

Answer 24

difference between systolic and diastolic pressure

Question 25

what is the pulse pressure for 110/60

Answer 25

50 systolic/diastolic

Question 26

Mean arterial pressure (MAP)

Answer 26

mean pressure of readings taken at intervals of cardiac cycle - varies w. gravity

Question 27

expansion and recoil of conducting arteries help maintain ....

Answer 27

steady flow of blood

Question 28

hypertension

Answer 28

high BP

Question 29

hypotension

Answer 29

low BP

Question 30

in the systemic circulation, systolic and diastolic pressures are ___ and have less range ____ from left ventricle

Answer 30

lower + have less ranger further away from left ventricle

Question 31

what are the 3 physiological factors that determine blood pressure

Answer 31

1. cardiac output 2. blood volume 3. resistance to flow (peripheral resistance)

Question 32

cardiac output

Answer 32

amount of blood ejected in 1 min

Question 33

blood volume is regulated by the

Answer 33

kidneys

Question 34

more volume = ___ pressure

Answer 34

more pressure

Question 35

resistance to flow is determined by

Answer 35

blood viscosity , vessel length, vessel diameter - vessel diameter is the biggest factor and length

Question 36

in a small diameter vessel, blood is slowed so resistance is ___

Answer 36

high

Question 37

blood flow is directly proportional to BP between how many points

Answer 37

2

Question 38

blood flow is inversely proportional to

Answer 38

peripheral resistance

Question 39

if resistance increases blood flow ___

Answer 39

decreases

Question 40

does pressure or resistance have a greater affect on flow?

Answer 40

resistance

Question 41

when P increases flow, ___

Answer 41

speeds up/ increases

Question 42

longer blood vessel means greater surface area with bloodd so resistance is

Answer 42

greater

Question 43

name of high pressure system which is 13% of total blood volume

Answer 43

systemic arterial system

Question 44

systemic venous system

Answer 44

very low pressure system - needs valves to prevent backflow - skeletal muscle contraction and thoracic pump help overcome force of gravity - makes up 64% of total blood volume

Question 45

is there is a change in 1/3 factors that determine BP what happens

Answer 45

compensated by changing other variables

Question 46

short term regulation of BP

Answer 46

nervous system + hormones adjust BP by changing peripheral resistance and CO

Question 47

long term regulation of BP

Answer 47

blood volume is altered in the kidneys

Question 48

what are the 2 mechanism of BP control

Answer 48

1. local autoregulation (blood flow in local areas) 2. central regulation (neural and endocrine) widespread

Question 49

what happens if autoregulation doesnt work?

Answer 49

neural and endocrine mechanisms take over

Question 50

explain the endocrine response at kidneys to low BP and volume, what are the prime hormones involved

Answer 50

kidneys act directly + indirectly to regulate arterial pressure and control BP long term directly - w/o hormones indirectly- renin-angiotensin-aldosterone ( constrict blood v, stimulate thrist, hold on to water via adh, hold on to Na+ via aldestrone)

Question 51

renal mechanisms mediate ___ term regulation of BP by altering what?

Answer 51

mediate long term regulation of BP by altering blood volume

Question 52

decreased blood volume = ___ BP

Answer 52

decreases

Question 53

what hormones are released via kidney (renal) when BP is low

Answer 53

renin EPO ACE

Question 54

short term regulation of BP hormonally via

Answer 54

changes in peripheral resistance

Question 55

short term hormones to regulate BP

Answer 55

adrenal medulla hormones (E + NE) = vasoconstriction angiotensin II = vasoconstriction ANP (atrial natriuretic peptides)= vasoconstriction ADH(vasopressin)= vasoconstriction only in severed cases of low BP

Question 56

vasoconstriction

Answer 56

narrow/ constricting blood vessels