Exam 2 – Cardio Ch 19 Flashcards Preview

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Flashcards in Exam 2 – Cardio Ch 19 Deck (69)
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1
Q

What percent of body weight is blood?

A

8%

2
Q

What percent of blood is plasma? Cells?

A

60%

40%

3
Q

What percent of total body water distribution is plasma?

A

5%

4
Q

What percent of total body water distribution is interstitial fluid?

A

15%

5
Q

What percent of total body water distribution is intracellular fluid?

A

40%

6
Q

What percent of total body water distribution is extracellular fluid?

A

20-30%

7
Q

What makes up extracellular fluid?

A

Plasma and interstitial fluid

8
Q

What is the density/weight of blood?

A

1 kg/liter or 1 gram/ml

9
Q

What percent of plasma is water? Protein?

A

92%

8%

10
Q

What happens during the short term control of blood pressure?

A

Autonomic sympathetic increases peripheral resistance

11
Q

Describe long term control of blood pressure

A

Renal control mechanisms

Sodium and extracellular fluid volume

12
Q

What is sodium a major determinant of?

A

Extracellular fluid volume

13
Q

What happens as sodium intake increases?

A

It stimulates thirst/drinking and ADH secretion

14
Q

What does a change in the sodium intake lead to?

A

Changes in extracellular fluid volume (ECFV)

15
Q

What is ECFV determined by?

A

The balance of sodium intake and output

16
Q

Is there more sodium or potassium in the extracellular compartment?

A

Na

17
Q

Is there more sodium or potassium in the intracellular compartment?

A

K

18
Q

What do the kidneys have a dominant role in?

A

Long term pressure control by regulating ECFV

19
Q

What happens as ECFV increases?

A

Arterial pressure increases

20
Q

What does the increase in arterial pressure, which is caused by an increase in ECFV, cause?

A

The kidneys to lose Na and water which will return ECFV and blood pressure to normal

21
Q

What does an increase in ECFV cause?

A

An increase in blood pressure which increases sodium excretion which increases ECFV (it’s a cycle)

22
Q

What is the effect of pressure to increase water excretion?

A

Pressure diuresis

23
Q

What is the effect of pressure to increase Na excretion?

A

Pressure natriuresis

24
Q

What do pressure natriuresis and diuresis require?

A

Normal kidney function

25
Q

What are determinants of long term blood pressure control?

A

Renal function and Na intake

26
Q

What is the equilibrium point on the renal function curve and salt and water intake line?

A

Where intake and output curves intersect

27
Q

What does the renal body fluid feedback system have in terms of gain?

A

Infinite gain: normal kidney can return high pressures to normal range

28
Q

Do changes in TPR have an affect on long-term arterial pressure level?

A

No

29
Q

What must be altered in order to have long-term changes in arterial pressure?

A

The renal function curve

30
Q

What does changing renal vascular resistance lead to?

A

Long-term changes in arterial pressure

31
Q

If you take a large piece of tissue from an animal, what have you taken?

A

A large amount of the extracellular fluid, which will change how the heart works because the fluid volume is different

32
Q

Look at the effect of ECFV on arterial pressure

A

Look at the effect of ECFV on arterial pressure

33
Q

What is the mean circulatory filling pressure?

A

The amount of blood coming back

34
Q

What is the overall effect of ECFV?

A

Increased extracellular fluid volume

35
Q

How does an increase in ECFV increase blood pressure?

A

Decreased kidney function

Increased NaCl intake

36
Q

Where is renin synthesized and stored?

A

In modified smooth muscle cells in afferent arterioles of the kidney

37
Q

What is renin released in response to?

A

A fall in pressure

38
Q

What does renin act on?

A

A substance called angiotensin to form a peptide called angiotensin II

39
Q

What is angiotensin I converted to angiotensin II by?

A

A converting enzyme located in the endothelial cells in the pulmonary circulation

40
Q

What happens when there is decreased arteriole pressure?

A

It is noted very quickly by the glomerular apparatus. This releases renin

41
Q

What happens when angiotensin II hits the lung?

A

We get angiotensinase

42
Q

What is angiotensin II?

A

The most powerful vasoconstrictor that can affect the body globally

43
Q

Look at renin-angiotensin system

A

Look at renin-angiotensin system

44
Q

What does the renin-angiotensin system cause?

A

Vasoconstriction
Na retention by direct and indirect acts on the kidney
Shift in renal function curve to the right

45
Q

What happens with direct acts on the kidney?

A

Decreased renal blood flow

More time for resorption

46
Q

What happens with indirect acts on the kidney?

A

ADH secretion

47
Q

What is the renin-angiotensis system important in?

A

Maintaining a normal AP during changes in Na intake

48
Q

What happens to renin as Na intake increases?

A

Its levels fall to near 0

49
Q

What happens to renin as Na intake decreases?

A

Its levels increase significantly

50
Q

What does the renin-angiotensin system cause the Na loading renal function curve to be like?

A

Steep

51
Q

What organs are important in the renin-angiotensin system?

A

Liver
Adrenal cortex
Lungs

52
Q

What does angiotensin have a direct effect on?

A

Adrenal cortex

53
Q

What will most of the angiotensin do?

A

Vasoconstriction of the arterioles

54
Q

What are factors which decrease renal excretory function and increase blood pressure?

A

Angiotensin II
Aldosterone
Sympathetic nervous activity
Endothelin

55
Q

What will total peripheral resistance do?

A

Raise the blood pressure

56
Q

What are factors which increase renal excretory function and decrease blood pressure?

A

Atrial natriuretic peptide
Nitric oxide
Dopamine

57
Q

What can dopamine cause?

A

Vasodilation globally

58
Q

What is a normal blood pressure?

A

Less than 120/80 mmHg

59
Q

What is a prehypertension blood pressure?

A

120-139/80-89 mmHg

60
Q

What is a hypertension blood pressure?

A

Greater than 140/90 mmHg

61
Q

What is the blood pressure for stage 1 hypertension?

A

140-159/90-99 mmHg

62
Q

What is the blood pressure for stage 2 hypertension?

A

160 or greater/100 or greater mmHg

63
Q

What percentage of hypertensive patients have primary/essential hypertension?

A

90%

64
Q

What is the cause of primary/essential hypertension?

A

Unknown, but most likely related to weight gain. 2/3 of essential hypertensives are overweight
Linked to genetics

65
Q

What does primary hypertension cause?

A

Loss of compliance of large arteries

66
Q

What are some causes for secondary hypertension?

A
Renal artery stenosis
Chronic renal disease
Primary hyperaldosteronism
Sleep apnea
Pheochromocytoma
Preeclampsia
Aortic coarctation
67
Q

How can you treat hypertension?

A

Drugs which affect renal blood flow

Drugs that inhibit Na reabsorption

68
Q

What do drugs which affect renal blood flow do?

A

Inhibition of sympathetic nervous system
Angiotensin converting enzyme inhibitors
Vasodilators

69
Q

What are drugs that inhibit Na reabsorption?

A

Diuretics

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