3.2 Physiology and Anatomy of Cardiovascular System

Question 1

What are the 4 chambers of the heart?

Answer 1

1. Right atria
2. Right ventricle
3. Left atris
4. Left ventricle

Question 2

What are the 4 valves of the heart?

Answer 2

1. Tricuspid (right)
2. Pulmonary
3. Bicuspid (left)
4. Aortic

Question 3

What are the 6 great vessels of the heart?

Answer 3

1. Superior vena cava
2. Inferior vena cava
3. Pulmonary trunk
4. Right pulmonary artery
5. Left pulmonary artery
6. Aorta

Question 4

Closure of heart valves cause vibrations in adjacent heart walls + blood, making the iconic heart sound “lub-dub”. What are the valves involved?

Answer 4

Closure of aortic valves at start of ventricular systole

Closure of semilunar valves at end of ventricular systole

Question 5

Blood is pumped through two circuits, what are they?

Answer 5

Pulmonary circuit = blood vessels that carry blood to and from lungs

Systemic circuit = blood vessels that carry blood to and from the rest of the body

Question 6

Where do the left coronary artery, the right coronary artery, and the great cardiac vein stem from?

Answer 6

Left = aortic sinus, jsut above aortic valve

Right = aortic root, right above aortic valve

Great cardiac vein = coronary sinus, right atria

Question 7

The cardiac conductive system is made from specialised cardiomyocytes connected through gap junction proteins called connexin 43. What are te components of this system?

Answer 7

1. Sinoatrial node
2. Intermodal pathway fibres
3. Atrioventricular node
4. AV bundle
5. R and L bundle branches
6. Purkinje fibres

Question 8

What are the meanings of endocardium, myocardium, space-pericardial, and epicardium?

Answer 8

Endocardium = heart endothelium

Myocardium = cardiac muscle cells intrinsically able to generate + conduct impulses

Space-pericardial = between parietal and visceral

Epicardium = double walled sac

Question 9

The cardiac cycle has two phases of stroke pump: the diastole and systole. What are the differences between them?

Answer 9

Diastole = heart chambers passively fill with blood returning from veins

(bicuspid + tricuspid valves open, pulmonary + aortic valves closed)

Systole = active contraction to pump blood to arteries

(bicuspid + tricuspid valves = closed, pulmonary + aortic valves = open)

Question 10

What is the cardiac cycle facilitated by?

Answer 10

Intrinsic pacemaker regions

Must be able to vary output to meet bodies need

Needs source of energy = high oxygen demand + ATP

Question 11

What is cardiac output?

Answer 11

Amount of blood the heart pumps in 1 minute

Stroke volume X beats per minute (BPM)

Question 12

What is Starling’s Law?

Answer 12

Preload increase = cardiac stroke volume increase = increased cardiac output

Question 13

Starling’s equation / forces are an equation which demonstrates what?

Answer 13

Role of hydrostatic + oncotic forces in fluid movement across capillary membrane

Useful in explaining oedema

Question 14

Blood pressure is the pressure of blood on the arterial wall. What are the two types of blood pressure value?

Answer 14

1. Diastolic pressure = when heart relaxes, bottom of pressure
2. Systolic pressure = when heart contracts, top of pressure

Question 15

Blood pressure = cardaic output X peripheral resistance. How is this regulated?

Answer 15

Blood volume = renin-angiotensin pathway

Heart Rate = sympathetic nervous system

Vessel resistance = sympathetic nervous system

Question 16

Cardiac control is managed short-term and long-term via two different systems / pathways. What are they?

Answer 16

1. Autonomous nervous system via BARORECEPTOR REFLEX = senses + regulates short-term chanegs in blood pressure
2. RENIN-ANGIOTENSIN pathway = hormonal control system for long term regulation of blood pressure

Question 17

The liver, kidneys, and lungs excrete important factors for the renin-angiotensin pathway, what are they?

Answer 17

Liver = Angiotensinogen

Kidney = Renin (when arterial blood pressure is down)

Lungs = Angiotensin Converting Enzyme (ACE)

Question 18

How does the renin-angiotensin pathway lead to long-term increases in blood pressure?

Answer 18

1. Angiotensinogen + renin = angiotensin
2. Angiotensin + ACE = Angiotensin II
3. Angiotensin II activates processes in adrenal cortex + brain to increase arterial pressure + blood volume

Question 19

What are the brain mediated processes in the renin-angiotensin pathway that lead to increases in arterial pressure + blood volume?

Answer 19

1. Encourages thirst
2. Produces vasopressin = kidney produces more renin and reabsorbs H2O + NaCl (useful when dirnk unavailable)

Question 19

What are the brain mediated processes in the renin-angiotensin pathway that lead to increases in arterial pressure + blood volume?

Answer 19

1. Encourages thirst
2. Produces vasopressin = kidney produces more renin and reabsorbs H2O + NaCl (useful when dirnk unavailable)
3. Vasopressin also affects blood vessels = vasoconstriction

Question 20

How does the adrenal cortex increase arterial pressure + blood volume in the renin-angiotensin pathway?

Answer 20

1. Produces aldosterone
2. Aldosterone acts similar to vasopressin = kidney produces renin and reabsorbs H2O + NaCl