CTB4

Question 1

What is blood pressure?

Answer 1

The force exerted by circulating blood on the walls of blood vessels.

Question 2

How is blood pressure measured?

Answer 2

Using a sphygmomanometer to record systolic and diastolic pressures.

Question 3

What is systolic pressure?

Answer 3

The pressure during ventricular contraction (systole).

Question 4

What is diastolic pressure?

Answer 4

The pressure during ventricular relaxation (diastole).

Question 5

What is pulse pressure?

Answer 5

The difference between systolic and diastolic pressures.

Question 6

What is mean arterial pressure (MAP)?

Answer 6

The average pressure in arteries during one cardiac cycle, calculated as MAP = diastolic pressure + 1/3 pulse pressure.

Question 7

What is vascular compliance?

Answer 7

The ability of blood vessels to stretch in response to pressure changes.

Question 8

How do arteries and veins differ in compliance?

Answer 8

Arteries are less compliant, while veins are highly compliant and act as reservoirs.

Question 9

What is vascular resistance?

Answer 9

The opposition to blood flow caused by vessel diameter, length, and blood viscosity

Question 10

What is Poiseuille’s Law?

Answer 10

Resistance is inversely proportional to the fourth power of vessel radius.

Question 11

What is the relationship between flow, pressure, and resistance?

Answer 11

Flow = Pressure / Resistance

Question 12

How does vessel diameter affect resistance?

Answer 12

A smaller diameter greatly increases resistance, reducing flow.

Question 13

What causes turbulent blood flow?

Answer 13

High velocity, abrupt changes in vessel diameter, or irregular vessel walls.

Question 14

What is laminar flow?

Answer 14

Blood flows in parallel layers with minimal friction, typical in healthy vessels.

Question 15

How does viscosity influence blood flow?

Answer 15

Increased viscosity (e.g., in polycythaemia) raises resistance and reduces flow.

Question 16

What is the primary site of vascular resistance?

Answer 16

Arterioles, due to their ability to constrict or dilate.

Question 17

What is the significance of capillary beds?

Answer 17

They allow nutrient, gas, and waste exchange due to their thin walls and low pressure.

Question 18

How does blood pressure change across the circulatory system?

Answer 18

It is highest in the aorta and decreases progressively to the venae cavae.

Question 19

What is the Windkessel effect?

Answer 19

Elastic arteries (e.g., aorta) dampen pressure fluctuations, ensuring continuous flow.

Question 20

How do baroreceptors regulate blood pressure?

Answer 20

Baroreceptors in the carotid sinus and aortic arch detect pressure changes and adjust heart rate and vessel tone.

Question 21

What is the baroreceptor reflex?

Answer 21

A rapid response that stabilises blood pressure via autonomic adjustments

Question 22

How does the sympathetic nervous system affect blood pressure?

Answer 22

It increases heart rate, contractility, and vasoconstriction to raise pressure.

Question 23

How does the parasympathetic nervous system affect blood pressure?

Answer 23

It decreases heart rate and promotes vasodilation to lower pressure.

Question 24

What is the role of the renin-angiotensin-aldosterone system (RAAS)?

Answer 24

RAAS regulates blood pressure by increasing blood volume and vasoconstriction.

Question 25

How does angiotensin II increase blood pressure?

Answer 25

By causing vasoconstriction and stimulating aldosterone release to retain sodium.

Question 26

What is the role of aldosterone in blood pressure regulation?

Answer 26

It increases sodium and water reabsorption, raising blood volume and pressure.

Question 27

What are the effects of vasopressin (antidiuretic hormone)?

Answer 27

It promotes water reabsorption in the kidneys and vasoconstriction.

Question 28

How does nitric oxide regulate blood flow?

Answer 28

NO causes vasodilation by relaxing smooth muscle in vessel walls.

Question 29

What is the role of endothelin-1?

Answer 29

It is a potent vasoconstrictor produced by endothelial cells.

Question 30

How does blood flow autoregulation work?

Answer 30

Local mechanisms adjust vascular resistance to maintain consistent flow despite pressure changes.

Question 31

What is reactive hyperaemia?

Answer 31

Increased blood flow following a period of restricted flow due to vasodilation.

Question 32

What is the significance of arterial compliance in pulse pressure?

Answer 32

Reduced compliance (e.g., in arteriosclerosis) increases pulse pressure.

Question 33

How does aging affect arterial compliance?

Answer 33

Aging reduces arterial compliance, leading to higher systolic pressure.

Question 34

What are the phases of the Korotkoff sounds?

Answer 34

Sounds heard during blood pressure measurement: Phase 1 (systolic pressure) to Phase 5 (diastolic pressure).

Question 35

What is orthostatic hypotension?

Answer 35

A sudden drop in blood pressure when standing, causing dizziness.

Question 36

How does exercise affect blood pressure?

Answer 36

Systolic pressure rises due to increased cardiac output, while diastolic pressure may remain stable or decrease.

Question 37

What is the significance of capillary hydrostatic pressure?

Answer 37

It drives fluid out of capillaries into interstitial spaces for nutrient exchange.

Question 38

What is oncotic pressure?

Answer 38

The pressure exerted by plasma proteins that pulls fluid into capillaries.

Question 39

How do veins facilitate venous return?

Answer 39

Through valves, skeletal muscle contractions, and respiratory pressure changes.

Question 40

What is venous pooling?

Answer 40

The accumulation of blood in veins, often due to prolonged standing or immobility.

Question 41

What is the relationship between total peripheral resistance and blood pressure?

Answer 41

Increased resistance raises blood pressure, while decreased resistance lowers it.

Question 42

How does low blood pressure affect organ perfusion?

Answer 42

It can lead to inadequate oxygen delivery and tissue hypoxia.

Question 43

What is the significance of preload in cardiac output?

Answer 43

Preload (end-diastolic volume) determines stroke volume via the Frank-Starling mechanism.

Question 44

What is afterload, and how does it influence cardiac output?

Answer 44

Afterload is the resistance the heart must overcome to eject blood; high afterload reduces output.

Question 45

How do beta-blockers lower blood pressure?

Answer 45

By reducing heart rate and contractility, lowering cardiac output.

Question 46

How do calcium channel blockers reduce blood pressure?

Answer 46

By inhibiting calcium influx in smooth muscle, causing vasodilation.

Question 47

What is the role of diuretics in managing hypertension?

Answer 47

They reduce blood volume by promoting sodium and water excretion.

Question 48

How does chronic hypertension affect the heart?

Answer 48

It increases afterload, leading to left ventricular hypertrophy and potential heart failure.