Chapter 20 Flashcards Preview

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Flashcards in Chapter 20 Deck (96):
1

during pressure gradient, what is the venous pressure gradient?

7-13 mm Hg

2

7-13 mm HG favoring blood movement to the heart

pressure gradient

3

the flow of blood back to the heart

venous return

4

venous return is achieved by 5 mechanisms:

1. pressure gradient
2. gravity
3. skeletal muscle pump
4. thoracic pump
5. cardiac suction

5

___ drains blood from the head and neck; large veins of head and neck are collapsed

gravity during venous return

6

___ is when the massaging of veins by muscle action; venous valves prevent back-flow

the skeletal muscle pump during venous return

7

___ pulls blood from abdominal to thoracic portion of inferior vena cava

the thoracic (respiratory) pump during venous return

8

___ expands the right atrium and pulls blood from inferior vena cava

cardiac suction

9

blood pressure in the veins is so __

low

10

downward motion of the diaphragm increases pressure in the abdominal cavity

inhale

11

upward motion of diaphragm increase the pressure in the thoracic cavity

exhale

12

the accumulation of blood

venous pooling

13

the accumulation of excess fluid in a tissue

edema

14

occurs when fluid filters into a tissue faster than it is reabsorbed

edema

15

CORRECT ESSAY: what do you think will happen to the rate of venous return during lifting when the thoracic cavity pressure decreases and remains when breathing is held?

Initially, it speeds up. But if you continue to hold breath it slows down and possibly even stop.

16

hypertensions, histamine, old age, inactivity, reduced venous return, right or left ventricular failure

increased capillary filtration

17

albumin deficiency, liver disease, dietary protein deficiency, kidney disease, severe burns

reduced capillary reabsorption

18

obstructed lymphatic vessels, surgical removal of lymph nodes

obstructed lymphatic drainage

19

why is the lymphatic system so important?

because it helps drain extra fluid

20

Why is it problematic when require to stand for long times?

- CO is reduced
- Profusion to the brain is reduced (hypoxic)
* syncope (fainting)
* varicose veins

21

what starts to build up in the brain during profusion?

carbon dioxide which leads to hydrogen ions

22

capillaries in ___ engage almost entirely in filtration

renal glomeruli

23

capillaries of ___ engage almost entirely in reabsorption

pulmonary alveoli

24

capillaries in ____ shift from reabsorption to filtration when BOP rises; muscles accumulate fluid

exercising muscles

25

what do traumatized tissues increase?

permeability and filtration

26

traumatized tissues release ____, ____, and ____

substance P, bradykinin, and histamine

27

any state in which cardiac output is insufficient to meet the body's metabolic needs

circulatory shock

28

caused by inadequate pumping by the heart

cariogenic shock

29

what causes cariogenic shock?

myocardial infarction (heart attack)

30

cardiac output is low because too little blood is returning to the heart

low venous return shock (LVR)

31

low blood volume due to hemorrhage, trauma, burns, dehydration

hypovolemic shock

32

blood flow impeded when a vain is comprised by a tumor, aneurysm or other cause

obstructed venous return shock

33

blood accumulates in the limbs instead of returning to the heart; can be due to inactivity or neurogenic shock

venous pooling (vascular) shock

34

form of venous pooling shock that results from sudden loss of vasomotor tone, allowing the vessels to dilate

neurogenic shock

35

bacterial toxins trigger vasodilation and increased capillary permeability

septic shock

36

results from exposure to an antigen to which a person is allergic, such as bee or venom

anaphylactic shock

37

septic shock and anaphylactic shock both included:

venous pooling, low venous return, capillary permeability and widespread vasodilation

38

what do antigen-antibody complexes do?

trigger the release of histamine, causes vasodilation and increased capillary permeability

39

during this degree of shock, homeostasis brings about spontaneous recovery

compensated shock

40

during this degree of shock, a life threatening positive feedback loop

decompensated shock

41

what happens in result of decompensated shock?

1. low cardiac output - myocardial ischemia & infarction disseminated intravascular coagulation (DIC)
2. brainstem ischemica - depressed cardiac & vasomotor centers

42

brief episodes of cerebral ischemia characterized by temporary dizziness, loss of vision, weakness, paralysis, headache and aphasia

transient ischemia attacks (TIA)

43

sudden death of brain tissue caused by ischemia

stroke / cerebrovascular accident

44

myocardial infarction can lead to __ shock

cariogenic

45

vessels that carry blood away from the heart

arteries

46

afferent vessels that carry blood back to the heart

veins

47

vessels that connect the smallest arteries to the smallest veins

capillaries

48

the walls of arteries and veins are composed of layers called what?

tunics

49

why are arteries called "resistance vessels"?

because they are are a strong resilient structure

50

distal to conducting arteries; lead to more specific organs or body regions

distributing artereis

51

most distal; too variable to be named

small arteries

52

microscopic, thin-walled vessels that connect the smallest arteriole to the smallest veins; endothelium only

capillaries

53

these capillaries are endothelial cells joined by tight junctions and separated by intercellular clefts

continous capillaries

54

continuous capillaries often have ___, cells with elongated tendrils that wrap around the capillary and contract consequently regulating blood flow

pericytes

55

fenestrated capillaries have ___, which allow for the rapid passage of small molecules but still retain most proteins and larger particles in the blood stream

filtration pores

56

endothelial cells riddle with patches of filtration pores

fenestrated capillaries

57

are important in organs that engage in rapid absorption or filtration in the kidneys, endocrine glands, small intestine, and choroid plexuses of the brain

fenestrated capillaries

58

which capillary conforms to the shape of the surrounding tissue?

sinusoids

59

which capillaries have large gaps between endothelial cells?

sinusoids

60

irregular blood filled spaces in the liver, bone marrow, and spleen

sinusoids

61

capillaries are organized into weblike networks called

capillary beds

62

in capillary beds supplied with met arterioles, there is a single smooth muscle cell that wraps like a cuff around the opening to each capillary; it acts as a ____ regulating blood flow

pre capillary sphincter

63

what happens if the pre capillary sphincter is constricted?

capillary bed shuts down

64

veins are subjected to really ____ blood pressure

low

65

what happens to veins in a pulmonary circuit?

blood is freshly oxygenated & pulmonary veins traditionally illustrated in red

66

what happens to veins in systemic circuit?

blood is relatively deoxygenated & systemic veins traditionally illustrated blue

67

the smallest of the veins

post-capillary venules

68

receive blood from the post capillary venules

muscular venules

69

most veins with individual names are in this category of veins

medium veins

70

many medium veins, especially in the limbs, exhibit inholdings of the tunica internal that meet in the middle of the lumen, forming ___, directed toward the heart.

venous valves

71

these prevent back flow of blood (vascular incompetence and varicose veins)

venous valves

72

innermost layer of a vessel wall

tunica interna

73

middle layer of a vessel wall

tunica media

74

the outermost layer of a vessel wall

tunica externa

75

tunica externa contain, __ __, small blood vessels found in the walls of larger vessels; these provide nourishment and waster removal services for the tissue of the larger vessels

vasa vasorum

76

biggest arteries that are closest to the heart

conducting arteries

77

blood flows through 2 consecutive capillary networks before returning to the heart

portal system

78

point of convergence between two blood vessels other than capillaries; bypass capillaries

anastomosis

79

blood flows from an artery directly into a vein and bypasses capillaries

arteriovenous anastomosis aka shunt

80

point where one vein empties directly into another

venous anastomoses

81

point where 2 arteries merge; provides collateral routes of blood supply to the tissue

arterial anastomoses

82

amount of blood flowing through an organ, tissue, or blood vessel in a given time

flow

83

flow per given volume or mass of tissue

perfusion

84

physical principles of blood flow, based mainly on pressure and resistance

hemodynamics

85

- flow is a matter of pressure vs. resistance: the greater the pressure difference between two points, the greater the flow; the greater the resistance, the less the flow

F=△P/R

86

how can blood flow be increased?

blood flow can be increased by increasing the pressure gradient or decreasing the resistance

87

force that the blood exerts against a vessel wall

blood pressure

88

peak arterial BP attained during ventricular contraction; minimum needed to force brachial artery open against cuff pressure

systolic pressure

89

minimum arterial BP occurring during ventricular relaxation between heartbeats; recorded at point when brachial artery remains patent between heartbeats

diastolic pressure

90

what is normal blood pressure?

120/75 mm Hg

91

the difference between systolic and diastolic pressure; measure of the amount of stress places on smaller vessels by each heartbeat

pulse pressure

92

the mean pressure you would obtain if you took measurements at several intervals throughout the cardiac cycle; measure of amount of stress placed on the blood vessels throughout the cardiac cycle

mean arterial pressure (MAP)

93

the increasing stiffness of arteries

arteriosclerosis

94

the growth of lipid deposits in the arterial walls

atherosclerosis

95

high blood pressure; chronic resting blood pressure higher than 140/90

hypertension

96

chronic low blood pressure

hypotension