chapter 21- vessels & circulation(cardiovascular system) Flashcards

1
Q

what is the term for a bypass vessel?

A

anastomosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

in arteries the outer edge of the tunica intima has an extra layer of elastin called
the what?

A

internal elastic membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

of the three layers of the vessel wall, what is the
thickest in veins?

A

tunica externa/tunica adventitia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

which class of arteries are involved in system vasoconstriction to increase blood pressure?

A

muscualr arteries/distrubtion artries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what brings blood to the capillary beds?

A

arterioles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what’s an arteriosclerosis caused specifically by lipid deposits?

A

atherosclerosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

typically capillary bed is composed of what capillaries whereas
fenestrated capillaries are specialized for transfer of large solutes or a high
volume of fluid?

A

continous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

sinusoids are designed to allow the exchange of what?

A

cells & large proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is the cycle of contraction and relaxation of a precapillary sphincter to control blood flow through a capillary bed?

A

vasomotion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

blood hydrostatic pressure drives fluid out of a capillary, what draws the fluid
back in?

A

osmosis (due to plasma proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what effect does lactic acid have on a precapillary sphincter?

A

dilation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

stimulation from the vasomotor centers will result in what effect?

A

vasoconstriction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

name the hormone produced by the atria that blocks thirst and prevents release of ADH

A

atrial natriuretic peptide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

how does ADH & Angiotensin II assist the situation short term after a
hemorrhage?

A

both trigger water retention & vessel constriction to keep blood pressure up

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

arteries (six main classes of blood vessels)

A

carry blood away fro heart, branch & decrease in diameter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

arterioles (six main classes of blood vessels)

A

smallest arterial branches connect to capillaries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

capillaries (six main classes of blood vessels)

A

tiny vessels where diffusion occurs between the blood & interstitial fluid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

venules (six main classes of blood vessels)

A

smallest veins, connect to capillaries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

veins (six main classes of blood vessels)

A

return blood to heart, converge & increase in diameter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

anastomoses (six main classes of blood vessels)

A

bypass connections between vessels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

vessel wall structure of arteries & veins

A

three main layers or tunics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

tunica intima/tunica interna (wall structure of arteries & veins)

A

-inner most layer
-endothelial cells with basal lamina of loose connective tissue containing elastic fibers (elastin)
-in arteries called internal elastic membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

internal elastic membrane

A

the extra layer of elastic fiber on the outer edge of the tunica interna in arteries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

tunica media (wall structure of arteries & veins)

A

-middle layer
-smooth muscle cells in loose CT with sheets of elastin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

external elastic membrane

A

an extra layer of elastic fibers on the tunica media in arteries

26
Q

tunica externa/tunica adventitia (wall structure of arteries & veins)

A

-outer most layer
-collagen-rich external CT sheath
-infiltrated with nerve fibers & lymphatic vessels
-large vessels contain vaso vasorum

27
Q

tunica externa/tunica adventitia in arteries

A

there is more collagen & scattered elastic fiber bands

28
Q

tunica externa/tunica adventitia in veins

A

there is extensive elastic fiber networks & bundles of smooth muscle cells

29
Q

arteries (arteries vs vein comparison)

A

-thicker walls
-more elastin & smooth muscle in tunica media
-thickest tunic = tunica media
-elastic walls recoil constricting lumen without BP
-circular in cross section
-no valves
-pleated endothelium
-internal & external elastic membranes

30
Q

veins (arteries vs veins comparison)

A

-thinner walls
-less elastin & smooth muscle in tunica media
-thickest tunic= tunica externa
-open lumen, no recoil
- collapse flat in cross-section
-valves = flaps of tunica intimate prevent backflow
-smooth endothelium
-no elastic membrane

31
Q

vein histology

A

large vein -> ,medium-sized vein -> venule -> fenestrated capillary

32
Q

artery histology

A

elastic artery -> muscular artery -> arteriole -> continous capillary

33
Q

pressure points (muscular arteries)

A

can be pinched off to control bleeding

34
Q

aneurysm (health problems with arteries)

A

pressure of blood exceeds elastic capacity of wall, causes bulge or weak spot prone to rupture, caused by chronic high BP or arteriosclerosis

35
Q

arteriosclerosis (health problems with arteries)

A

variety of pathological conditions causing changes in walls that decrease elasticity (thickening)

36
Q

focal calcification (health problems with arteries)

A

smooth muscle degenerates, replaced by calcium salts

37
Q

atherosclerosis (health problems with arteries)

A

lipid deposit buildup

38
Q

stroke/cerebrovascular accident (CVA) (health problems with arteries)

A

interruption of arterial supply to portion of brain (embolism, atherosclerosis), brain tissue dies & function is lost

39
Q

capillaries

A

-designed to allow diffusion to/from the tissues
-consists of tunica intima only (endothelium + basal lamina)
-8μm
-only vessels with thin enough wall structure to allow complete diffusion

40
Q

continuous capillaries

A

-normal diffusion to all tissues except epithelium & cartilage
-complete endothelium, tight junctions

41
Q

fenestrated capillaries

A

-high-volume fluid or large solute transfer
-pores/fenestrations span endothelium
-ex: choroid plexus, endocrine organs, intestine, kidney

42
Q
A
43
Q

capillary beds

A

a network of small blood vessels that allow the exchange of gas, water, and nutrients, include continuous, fenestrated & sinusoid

44
Q

not enough total blood to fill all capillaries at once:

A

flow through capillary bed must be controlled based on need via pre-capillary sphincters (vasomotion)

45
Q

vasomotion

A

-cycle of contraction/relaxation
-sphincter relaxed = flow in capillary bed
-sphincter constricted = capillary bed empty, flow through anastomoses

46
Q

veins

A

-designed to return blood to heart, can serve as blood reservoir, thin walls but large lumens
-thin tunica media with little smooth muscle or elastin
-tunica externa contains elastin & smooth muscle
-tunica intima contains valves to prevent back-flow

47
Q

veins pressure:

A

-pressure from heart drives blood flow in arteries, pressure in veins often too low to oppose gravity
=skeletal muscle movement required to “squish” blood through veins
-valves in tunica intima ensure one-way movement

48
Q

venule

A

-collect blood from capillary beds
-average diameter 20μm (range 8μm)
-small ones lack tunica media

49
Q

medium vein

A

2-9mm

50
Q

large vein

A

3cm

51
Q

varicose veins & hemorrhoids (health problems with veins)

A

resistance to flow (gravity, obesity) causes pooling above valves, veins stretch out

52
Q

blood reservoir (health problems with veins)

A

venous system contains 65-70% total blood volume, can constrict during hemorrhage to keep volume in capillaries & arteries near normal

53
Q

arteries

A

-designed to change diameter, elastic & muscular, thick walls
-tunica externa contains collagen
-sympathetic stimulation = vasoconstriction
-smooth muscle relaxes = vasodilation

54
Q

elastic arteries (conducting arteries)

A

-transport large volumes away from heart
-2.5 cm
-elastin in all 3 tunics
-stretch (ventricular systole) & rebound (ventricular diastole)
-not involved in system vasoconstriction

55
Q

muscular arteries (distribution arteries)

A

-transport blood to organs & tissues
-10mm-0.3mm
-more smooth muscle & less elastin in tunica media than elastic arteries
-involved in systemic vasoconstriction via sympathetic stimulation

56
Q

arterioles (resistance vessels)

A

-connect blood supply to capillary beds
-300μm-10μm
-all 3 tunics then with few elastic fibers
-involved in local vasoconstriction via endocrine or sympathetic stimulation

57
Q

anastomoses

A

-bypass routes between vessels
-not present in retina, kidney or spleen
-more common in veins

58
Q

blood flow (physiology of circulation)

A

volume of blood flowing through a vessel in given period (total body flow = CO)

59
Q

blood pressure (physiology of circulation)

A

force per unit area exerted on vessel by blood (mmHg) blood flows from high pressure -> low

60
Q

resistance (physiology of circulation)

A

opposition of blood flow, friction
-increase blood viscosity = increase resistance
-increase vessel length = increase resistance
-decrease vessel diameter = increase resistance