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Anatomy & Physiology > Cardiovascular system > Flashcards

Flashcards in Cardiovascular system Deck (113)
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31

What are C-reactive proteins?

Produced by Liver and maybe present in the blood in inactive form
Converted to an active form during inflammation
May play a direct role in development of atherosclerosis by promoting the uptake of LDLs by macrophages

32

List the risk factors associated with CAD?

Smoking
High BP
Diabetes
High Cholesterol
Obesity
Sedentary Lifestyle
Family History of CAD

33

What is CAD?

Coronary Artery Disease - The effects of the accumulation of atherosclerotic plaques in coronary arteries that lead to a reduction in blood flow to the myocardium

34

Why does hypertension put a strain on the heart?

It increases aortic pressure meaning the pressure in the Left Ventricle must be higher to overcome this pressure and move blood out into the aorta. Eventually ejection gets harder and stroke volume and cardiac output diminish.

35

List some negative inotropic agents which reduce the heart muscle contractility?

Calcium channel blockers
Some anaesthetics

36

List some positive inotropic agents affecting stroke volume

Neurotransmitters - norepinephrine
Hormones - epinephrine and thyroxine
Drugs - Digoxia

37

What are inotropic agents?

Substances that increase or decrease contractility in cardiac muscles (and consequently increase or decrease stroke volume)

38

What 3 factors affect stroke volume?

PRELOAD (Stretch of ventricle muscle prior to contraction)
CONTRACTILITY (forcefulness of ventricular muscle contraction)
AFTERLOAD (Pressure that must be overcome before ventricles can eject blood)

39

What effect to Calcium ions have on the heart?

A moderate increase in Ca 2+ (extra or intracellur) increases heart rate and contraction force.

40

What affect to elevated levels of sodium and potassium ions have on the heart

Decreased heart rate and contraction force

41

What hormones affect heart rate?

Thyroxine
Epinephrine

42

What is one of the signs of hyperthyroidism?

Tachycardia

43

What can trigger the adrenal medullae to release hormones?

Exercise
Stress
Excitement

44

What effects do norepinephrine and epinephrine have on the heart?

They enhance the heart's pumping effectiveness by increasing both heart rate and contraction force.

45

Which part of the body releases epinephrine and norepinephrine?

Adrenal Medullae

46

What are baroreceptors and where are they located?

Sensory receptors
Provide input to Cardiovascular centre
They are neurons (nerve cells) sensitive to changes in Blood Pressure changes
Located in arch of the aorta and carotid arteries

47

Which nerves release the neurotransmitter acetylcholine and which nervous system do they belong to?

Vagus (x) nerves
Parasympathetic Nervous System

48

Which neurotransmitter decreases heart rate and which node does it affect?

Acetylcholine (ACh)
Sino-atrial Node - SA node

49

Which nerves sends signals to the CV Centre?

Glossopharyngeal (IX) nerves
Vagus (X) nerves

50

Where does the CV centre direct output? (in relation to regulation of the heart)

Increases or decreases frequency of nerve impulses sent out to both sympathetic and parasympathetic branches of the ANS

51

What is Frank Starling Law of the heart?

Within limits, the more the heart is stretched as it fills during diastole, the greater the force of contraction during systole.

52

What stimulates the heart to contract more forcefully? (Tip: hormones & medication)

ANS - Epinephrine/Norepinephrine
Increased Ca2+ levels in interstitial fluid
Digitalis (Medication)

53

What will decrease the force of cardiac contractions? (Tip: hormones etc)

Inhibition of Norepinephrine & epinephrine (sympathetic division of ANS)
Anoxia (Absence of oxygen)
Acidosis (Excess acid in body fluids)
Some Anaesthetics
Increased K+ levels in interstitial fluid

54

What happens to stroke volume if pressure in the pulmonary trunk and aorta is higher than normal?

The semi-lunar valves open later than normal, stroke volume decreases and more blood remains in the ventricles at the end of systole.

55

What are the effects of alcohol, caffeine or cigarettes on the body? i.e. NS, Heart etc

Stimulate sympathetic nervous system
Elevate heart rate and BP
Thereby increase risk of hypertension

56

Where does the CV centre direct output? (In relation to regulation of the heart)

Increases or decreases frequency of nerve impulses sent out to both sympathetic and parasympathetic branches of the ANS

57

From where does the CV Centre in the medulla oblongata receive input?

1. A variety of sensory receptors
2. Higher Brain centers e.g. limbic and cerebral cortex

58

Which region of the brain does Nervous system regulation of the heart originate?

Cardiovascular Centre (CV) of the medulla oblongata

59

What are the common causes of congestive heart failure? (Tip: There are 4!)

Coronary Artery Disease
Long term high blood pressure
Myocardial Infarction
Valve Disorders

60

What leads to peripheral oedema in RSHF?

If the right ventricle fails, first blood backs up in the systemic blood vessels - most notable in swelling in feet and ankles.