Cardiovascular system and the effects of ageing

Question 1

The cardiac cycle consists of?

Answer 1

A full sequence of contraction (systole) and relaxation (diastole) of the heart

Question 2

What is the sequence of electrical activity?

Answer 2

Sinoatrial node, atrioventricular node, bundle of his, left and right bundle branches and purkinje fibres,

Question 3

What is end diastolic volume (EDV)?

Answer 3

VOlume of blood at the end of ventricular filling

Question 4

What is stroke volume?

Answer 4

Amount of blood ejected from each ventricle during systole

Question 5

What is End-systolic volume (ESV)?

Answer 5

AMount of blood remaining in the ventricles after the end of contraction

Question 6

Ejection Fraction (EF) is?

Answer 6

The percentage of EDV pumped from the ventricles

Question 7

Cardiac Output (Q) is?

Answer 7

The bvolume of blood pumped by each ventricle per minute

Question 8

What are physiological factors influencing stroke volume?

Answer 8

Filling Pressure, Stroke volume, Arterial pressure opposing ejection, contractility, energy of contraction and total peripheral resistance.

Question 9

As we age the heart…

Answer 9

Increases in mass with age

Question 10

What are 3 factors the slow down the contraction of the myocardium in older adults?

Answer 10

Slower calcium reuptake by sarcoplasmic reticulum, changes in myosin heavy chain compositions of myocytes, and prolonged action potential.

Question 11

Blood pressure is a product of?

Answer 11

Cardiac output and peripheral resistance

Question 12

What exerts primary influence over vascular resistance in the arterial system?

Answer 12

Small arterioles

Question 13

What are the two primary factors for adequate blood delivery?

Answer 13

Pressure driving the blood, and state of the resistance in the arteries and arterioles.

Question 14

The three structures are arteries and arterioles

Answer 14

Tunica intima (endo), tunica media (smooth muscle cells), and tunica adventitia (collagen fibres)

Question 15

Two factors that influence major conduit arteries (aorta) to get stiffer and longer with age?

Answer 15

Thickening of the structural materials that make up vessel walls and Increase in sympathetic tone of smooth muscle

Question 16

What is the key mechanism of Vascular endothelial dysfunction responsible for increase risk of CVD in ageing.

Answer 16

Reduced bioavailability of nitric oxide.

Question 17

High levels of sympathetic nerve activity result in…

Answer 17

Increases in peripheral vascular resistance and ultimately hypertension.

Question 18

Arterial stiffness affects blood pressure by?

Answer 18

Elevating pulse wave velocity, Reducing the ability to absorb energy during systole and Elevated systolic BP

Question 19

Elevated Sympathetic nerve activity affects BP by?

Answer 19

More vasoconstriction, Greater vascular resistance and Elevated blood pressure

Question 20

Maintenance of arterial BP at a constant level allows each organ to…

Answer 20

Control its own Perfusion to help sufficiently meet its own metabolic needs.

Question 21

Exercise capacity falls with age (VO2max dropping 10% per decade from 25) due to?

Answer 21

Decreased cardiac output, Decreased a-vO2 diff and loss of muscle mass.

Question 22

Blood flow in ageing limbs at rest is reduced with age, what factors influence this?

Answer 22

Often elevated MSNA (increasing vascular tone), fewer blood vessels available and/or inability to dilate blood vessels, and POTENTIAL physical INactivity.