Regulation of Blood Pressure and Cardiac Function Flashcards Preview

[OS 205] Thorax > Regulation of Blood Pressure and Cardiac Function > Flashcards

Flashcards in Regulation of Blood Pressure and Cardiac Function Deck (75)
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1
Q

Responsible for Vascular Adjustments?

A

Change in tone of smooth muscle tissue

2
Q

Vasodilators work on Arterioles, Veins, or Both?

A

Only on Arterioles

3
Q

Sympathetic nerves release?

A

Norepinephrine

4
Q

Receptors for Norepinephrine

A

Alpha-1 Adrenergic Receptors

5
Q

Effect of Norepinephrine on Vascular Smooth Muscle

A

Vasoconstriction

6
Q

The Brain, Heart, and Skeletal Muscles blood flow closely follow what?

A

Metabolic Rate

7
Q

Skin and Kidney blood flow is regulated by?

A

Sympathetic Nerves (Rather than metabolic rate as the others are)

8
Q

Functions of Blood Flow (6)

A
  1. Delivery of Oxygen
  2. Delivery of Nutrients (Glucose)
  3. Removal of CO2
  4. Removal of H Ions
  5. Maintenance of Proper Concentration of other Ions
  6. Transport of Hormones
9
Q

Local Blood Flow Regulation is regulated by? In organs, these are regulated by?

A
  1. Muscular arteries and large arterioles

2. In organs by metarterioles and endothelial cells of capillaries

10
Q

Vasodilator Theory

A

Endothelial tissue produce a vasodilator substance in response to availability of O2 and Nutrients

11
Q

Oxygen Lack Theory

A

Oxygen is required to allow muscle contraction, lack of this causes local arterioles and metarterioles to relax and dilate

12
Q

Reactive Hyperemia

A

Transient increase in blood flow following a period of ischemia

13
Q

Active Hyperemia

A

Increase in blood flow associated with increased metabolic activity (Such as in exercise)

14
Q

Vasoconstrictor Agents (4)

A

Norepinephrine and Epinephrine
Angiotensin II
Vasopressin
Endothelin

15
Q

Vasodilator Agents (2)

A

Bradykinin

Histamine

16
Q

Increase in Calcium (Constrict or Dilate)

A

Vasoconstriction

17
Q

Increase in Potassium (Constrict or Dilate)

A

Vasodilation

18
Q

Increase in Magnesium (Constrict or Dilate)

A

Powerful Vasodilation

19
Q

Low pH (Constrict or Dilate)

A

Dilatation of Arterioles

20
Q

Acetate and Citrate (Constrict or Dilate)

A

Mild Vasodilation

21
Q

Increase in CO2 (Constrict or Dilate)

A

Moderate Dilation in other Parts (Especially in the Brain)

22
Q

Which Vessels are Not INnervated by the Sympathetic Nervous System?

A

Capillaries
Pre-capillary Sphincters
Metarterioles

23
Q

Most Important Part for Regulation of Circulation

Why?

A

Sympathetic Nervous System

Most blood vessels do not have parasympathetic innervations

24
Q

What can pass the Blood-Brain Barrier

A

Glucose and CO2

25
Q

Heart is Innervated By?

A

Sympathetic and Parasympathetic Nerves

26
Q

Parasympathetic Nerves (Vagi) effect on the Heart?

A

Lowers BPM

27
Q

If Heart is De-Innervated, Will it Beat Faster or Slower?

A

It will beat faster, unlike abrupt termination of response to vagal activity; effects of sympathetic stimulation will only slow gradually after stimulation is stopped

28
Q

Location of Vasomotor Center

A

Medulla and Upper Pons

29
Q

Vasomotor Center Transmits What Impulses

  1. Vagus Nerve
  2. Spinal Cord
A
  1. Parasympathetic

2. Sympathetic

30
Q

Vasovagal Reflex

A

Compression of Carotid Arteries slows down HR

31
Q

Chemoreceptors Location

A

Carotid and Aortic Bodies

32
Q

Chemoreceptors Sensitive To? (3)

A
  1. O2 Lack
  2. CO2 Excess
  3. H+ Excess
33
Q

Volume Reflex

A

Stretch in Atria causes Diuretic Effect

Increase in GFR -> Increased Urine Output -> Decrease in BP

34
Q

Bainbridge Reflex

A

Increase in HR in response to atrial stretch

Prevents damming of blood to the veins

35
Q

Chemoreceptor Reflex

A

Decreases flow in artery as result of hypoxic conditions

36
Q

CNS Ischemic Response (a.k.a.?)

A

Cushing Reflex

Intense vasoconstrictor stimulation

37
Q

When is the Cushing Reflex stimulated?

When is it maximal?

A

BP < 60mmHg

BP < 15-20mmHg

38
Q

Abdominal Compression Reflex

Effect

A

Stimulation of the baroreceptor/chemoreceptor reflex causes stimulation o the skeletal muscles, especially in the abdomen

Pushes blood back to the heart

39
Q

Renal Function Curve

What happens when too much ECF?

A

Arterial pressure rises causing the kidney to excrete more urine

40
Q

Infinite Feedback Gain

A

Water and salt output must equal intake

41
Q

Chronic Hypertension:

What happens to

  1. Peripheral Resistance
  2. Cardiac Output
  3. Fluid Volume Levels
A

Increased peripheral resistance
Cardiac output eventually returns to normal
Return to normal fluid volume over time

42
Q

Angiotensin II Functions (3)

A
  1. Vasoconstriction
  2. Decreased secretion of salt and water
  3. Raises BP halfway to normal after sudden Hypotension
43
Q

How long for Angiotensin II to be fully active?

A

20 Minutes

44
Q

Angiotension II Pathway resulting from Decreased Arterial Pressure

A

Decreased Pressure -> Renin -> Angiotensinogen -> Angiotensin -> Angiotensin II -> Vasoconstriction + Renal Retention of Salt and Water -> Increased Arterial Pressure

45
Q

Factors Causing Hypereffectivity

A
  1. Nervous Excitation

2. Hypertrophy

46
Q

Hypoeffective Heart

A

Increased venous return with no accompanying increase in cardiac output

47
Q

Factors Causing Hypoeffectivity (6)

A
  1. Inhibition of Nervous Excitation
  2. Abnormal Rhythm or Rat eof Heart
  3. Valvular Disease
  4. Congenital Heart Disease
  5. Myocarditis
  6. Cardiac Anoxia
48
Q

Beri-Beri

A

Lack of thiamine diminishes cell’s ability to use nutrients

Cells send signal to heart to beat faster to deliver more nutrients

49
Q

Arteriovenous Fistula

A

Abnormal connection between major artery and vein

Diminishes peripheral resistance (Bypasses microcirculation)

50
Q

Hyperthyroidism

A

Increased BMR

51
Q

Anemia

A

Diminished oxygen delivery and viscosity (Hypoviscosity)

52
Q

Pathologically High Cardiac Outputs (4)

A
  1. Beri-beri
  2. Arteriovenous Fistula
  3. Hyperthyroidism
  4. Anemia
53
Q

Pathologically Low Cardiac Output (2)

A
  1. Decreased Pumping Effectiveness of heart

2. Decreased Venous Return

54
Q

Normal External Pressure

A

-4 mmHg

55
Q

Cardiac Tamponade

A

Accumulation of fluid in the pericardium around the heart

56
Q

Goldblatt Hypertension

A

Results from compression/obstruction of renal arteries or its branches

57
Q

Integrated System that Acts Within Seconds

A
  1. Baroreceptors
  2. Chemoreceptors
  3. CNS Ischemic REsponse
58
Q

Integrated System That Acts Within Minutes

A
  1. Renin-Angiotensin System
  2. Stress Relaxation of Vasculature
  3. Capillary Fluid Shift Mechanism
59
Q

Cardiac Output

A

Amount of blood pumped into aorta each minute by the heart

60
Q

Venous Return

A

Quantity of blood flowing from veins into right atrium each minute

61
Q

Cardiac Output should equal?

A

Venous Return

Improving cardiac output must be accompanied with improved venous return

62
Q

Normal CO for Men, For Women?

A

5.6 liters/min; 10-20% less for women

63
Q

Primary Controller of Cardiac Output

A

Various factors of Peripheral Circulation that Affect Venous Return

64
Q

Frank-Starling Law of the Heart

A

Increased blood flow into heart stretches out cardiac chambers

Additional stretch causes muscle fibers to contract with increased force

Heart pumps out all the additional blood

65
Q

Factors Affecting Venous Return (3)

A
  1. Right Atrial Pressure
  2. Mean Systemic Filling Pressure
  3. Resistance to Blood Flow
66
Q

Effect of Increased RA Pressure on Venous Return

A

Lowers Venous Return

67
Q

When does Venous Return Decrease to 0?

A

When the RA Pressure reaches 7mmHg (Mean Systemic Filling Pressure)

68
Q

Greater Mean Systemic Filling Pressure effect on Venous Return Curve

A

Shifts Upward and Right

69
Q

Greater Difference Between RA and Mean Systemic Filling Pressure

A

Greater Venous Return

70
Q

Compensation for Acute Failure By Sympathetic Reflexes

A

Pumps more vigorously

Increased tone of vasculature, Increased RA pressure

71
Q

Chronic Stages of Failure

A

Renal Retention of Fluids and Increase in Blood Volume

72
Q

Fluid Retention in Heart Failure

A

Fall in cardiac output causes fall in urine output

73
Q

Treatment of Decompensation (3)

A
  1. Strengthening of Heart (Digitalis, Inotropes)
  2. Administering Diuretics
  3. Reducing Water and Salt Intake
74
Q

Decompensated Heart Failure

A

Low CO prevents kidney from excreting necessary daily amounts of fluid and salt, leading to edema

75
Q

Cardiogenic Shock

A

Heart is too damaged, unable to pump enough blood to keep body alive