The Cardiovascular System

Question 1

What ventricle is thicker? Why is this?

Answer 1

Left ventricle. Has to pump blood around the whole body.

Question 2

How many heart valves are there?

Answer 2

4

Question 3

What opens and closes valves?

Answer 3

Pressure gradients.

Question 4

What structures orientate the valves in the correct positions, yet have no role in valve opening.

Answer 4

Chord tendinae and papillary muscles.

Question 5

What is the role of the semilunar valves?

Answer 5

Control the exit of blood and prevent back flow.

Question 6

As you age what happens to the heart valves?

Answer 6

Changes to the collagen and elastin.

Question 7

What are the consequences of calcification of the aortic valve?

Answer 7

Narrows the opening and reduces the blood flow. Heart has to work harder to pump blood, causes weakening of the heart muscle.

Question 8

Describe the 2 heart sounds.

Answer 8

1. Atrioventricular valves closing.

2. Pulmonary and aortic valves closing.

Question 9

What could a third heart sound indicate?

Answer 9

Two way movement of blood.

(Could indicate heart failure.) or tensing of the chord tendinae.

Question 10

What is systole?

Answer 10

Contraction.

Question 11

What is diastole?

Answer 11

Relaxation.

Question 12

During systole the ventricle are not fully..?

Answer 12

Emptied.

Question 13

What is stroke volume?

Answer 13

The amount of blood ejected per beat.

Question 14

What is the principle of Starling’s law?

Answer 14

The more blood the heart is filled with, the greater the heart will contract.

Question 15

What is cardiac output?

Answer 15

Stroke volume X heart rate

Question 16

Explain the process of conduction in contracting the heart.

Answer 16

Impulse is generated in the SA node and spreads over the atria, followed by the ventricles.

Both atria/ventricles will contract at the same time on both sides.

Conduction is rapid and coordinated.

Question 17

When does blood flow occur?

Answer 17

During diastole. As during systole the contracting restricts the coronary arteries.

Question 18

What is the role of the SA node?

Answer 18

Determines heart rate.

Question 19

What is the role of the AV node?

Answer 19

Slows conduction and can act as a secondary pacemaker.

Question 20

What is the role of the purkinje fibres?

Answer 20

Fibres interlock with myocytes to help spread the impulse across the ventricles.

Question 21

What effect does the sympathetic innervation have on the heart?

Answer 21

Speeds up heart rate by increasing Ca permeability. (Action of noradrenaline)

Question 22

What effect does the parasympathetic innervation have on the heart?

Answer 22

Slows down the heart rate by increasing the K permeability. (action of acetylcholine)

Question 23

What medication is used to manage arrhythmia?

Answer 23

Digoxin

Question 24

What detects changes in cardiac output and feedsback to the brain?

Answer 24

Baroreceptors.

Question 25

What adrenoreceptor is primarily found on nodal tissue, the conducting system and myocardium?

Answer 25

B1

Question 26

List the effects of adrenoreceptors.

Answer 26

Positive entropy: Force of contraction. Positive chronotrophy: Increases heart rate. Positive lusitrophy: Rate of relaxation. Positive dromotrophy: Spped of conduction.

Question 27

When are beta agonists used?

Answer 27

In short term treatment of cardiac arrest etc.

Question 28

Where does the vagal nerve terminate?

Answer 28

On nodal tissue.

Question 29

Where does the right vagus nerve terminate?

Answer 29

The SA node.

Question 30

Where does the left vagus nerve terminate?

Answer 30

AV node

Question 31

What drugs are used to treat bradycardia by increasing the heart rate.?

Answer 31

Vagolytic drugs.

Question 32

What is the charge on the inside of a cell at resting potential?

Answer 32

Negative.

Question 33

Which ion concentrating is greatest inside the cell?

Answer 33

Potassium (K)

Question 34

Which ion concentrating is greatest outside the cell?

Answer 34

Calcium (Ca) and sodium (Na).

Question 35

What charge is depolarisation achieving?

Answer 35

Moving towards a more positive charge.

Question 36

The movement of what ion achieves depolarisation?

Answer 36

Initially the movement of sodium into the cell depolarises the cell, however once the threshold is reached calcium also moves into the cell.

Question 37

The movement of what ion achieves repolarisation?

Answer 37

The movement of potassium out of the cell.

Question 38

What pressure is higher? Systolic or diastolic?

Answer 38

Systolic

Question 39

Describe the mean arterial pressure calculation.

Answer 39

Diastolic blood pressure + 1/3 pulse pressure. Pulse pressure= systolic - diastolic.

Question 40

In relation to pressure; What do arterioles have the ability to do?

Answer 40

Dissipate pressure.

Question 41

Name a characteristic of a venule.

Answer 41

Very distensible.

Question 42

Name the 2 main factors that affect transport.

Answer 42

Hydrostatic pressure (favours outwards movement) and Colloid pressure (favours inwards movement).

Question 43

At what end is hydrostatic pressure greater?

Answer 43

Arteriole.

Question 44

Explain colloid pressure

Answer 44

Plasma proteins too big to leave the the capillary, so they remain and draw fluid back into the capillary.

Question 45

Deoxygenated blood from pulmonary circulation travels from where to where?

Answer 45

Right ventricle to the lungs.

Question 46

Oxygenated blood from pulmonary circulation travels from where to where?

Answer 46

The lungs to the left side of the heart

Question 47

Name the sections of the mediastinum?

Answer 47

Inferior, posterior, anterior, middle and superior.

Question 48

What part of the mediastinum is subdivided into 3 sections (ant, mid, post)

Answer 48

The inferior mediastinum

Question 49

What structure that has an immune function is contained within the superior mediastinum?

Answer 49

The thymus.

Question 50

What arteries supply heart muscles?

Answer 50

Coronary arteries.

Question 51

What is unique about coronary arteries?

Answer 51

They are end arteries.

Question 52

What vein drains structures from the heart upwards?

Answer 52

The superior vena cava.

Question 53

What vein drains structures from below the heart?

Answer 53

The inferior vena cava.

Question 54

What is the function of the ductus venosus?

Answer 54

Diverts the babies blood away from the liver and to the heart.

Question 55

When is the ductus venous closed?

Answer 55

When the umbilical chord is cut.

Question 56

What is the foramen ovale?

Answer 56

A hole in the heart that passes blood from the right atrium to the left atrium. (Right ventricle not needed as the baby is not using its lungs in the womb)

Question 57

When is the foramen oval closed?

Answer 57

When the baby cries for the first time. Pressure surge closes he hole.

Question 58

What is the depression called once the foramen oval is closed?

Answer 58

Fossa ovalis. (right atrium)

Question 59

What is the function of the ductus arteriosus?

Answer 59

Diverts blood from the pulmonary trunk to the aorta.

Question 60

What is a characteristic of arteries closer to the heart?

Answer 60

More elastic.

Question 61

What is a characteristic of arteries further away from the heart?

Answer 61

More muscular.

Question 62

What kind of valves are atrioventricular valves?

Answer 62

Tricuspid valves

Question 63

Name the semilunar valves of the heart.

Answer 63

Aortic and pulmonary.

Question 64

What is the function of semilunar valves?

Answer 64

Controls the exit of blood.

Question 65

What structures do semilunar valves lack?

Answer 65

Chord tendinae

Question 66

What structures are present in the veins of the limbs but not the head and neck?

Answer 66

Valves.

Question 67

What is the function of baroreceptors?

Answer 67

Mechanoreceptors that detect changes in pressure via the stretch of arterial walls.

Question 68

What cranial nerve does the carotid sinus send messages to the brain via?

Answer 68

CN 9 | Glossopharyngeal.

Question 69

What cranial nerve does the aortic arch send messages to the brain via?

Answer 69

CN 10 | Vagus

Question 70

What baroreceptors are more sensitive?

Answer 70

Carotid sinus

Question 71

********** DONT UNDERSTAND | What adrenoreceptos are present on the nucleus tracts solitari?

Answer 71

A2 (inhibits bulbar circulatory system and activates the vagal nucleus) B1 (activates the bulbar circulatory centres and inhibits the vagal nucleus.) Bulbar circulatory system responsible for noradrenaline. Vagal nucleus: Responsible for acetylcholine

Question 72

What adrenoceptor is activated when blood pressure falls?

Answer 72

B1. Therefore reduces acetylcholine production and heart rate increases. Increases noradrenaline production and force of contraction/peripheral resistance increases.

Question 73

What adrenoceptor is activated when blood pressure rises?

Answer 73

A2. Increases acetylcholine production, heart rate decreases. Decreases noradrenaline production, reduction in peripheral resistance/force of contraction.

Question 74

Name some a2 agonists.

Answer 74

Clonidine. | Alpha-methyldopa.

Question 75

What is the function of adenosine?

Answer 75

Vasodilator

Question 76

What condition is nicorandil used to manage?

Answer 76

Angina.

Question 77

What condition increases your risk of getting critical limb ischaemia?

Answer 77

Diabetics.

Question 78

Name the 4 factors controlling blood flow

Answer 78

Length of the tube. Viscosity of blood. Pressure gradient. Cross section of the tube.

Question 79

Name a clinical condition related to blood viscosity.

Answer 79

Deep vein thrombosis. | Blockage of the vein. Blockage can break off and lodge somewhere else.

Question 80

What does dehydration do to blood viscosity?

Answer 80

increases the viscosity.

Question 81

What effect does branching have on blood flow?

Answer 81

Creates more resistance so blood flow decreases.

Question 82

Where is branching of vessels useful?

Answer 82

In areas where gas exchange occurs. | Higher resistance creates a slower flow and more time for the gas exchange to occur.

Question 83

What is preload?

Answer 83

End diastolic volume (left ventricle)

Question 84

What effect do nitrates have?

Answer 84

Cerebral vasodilation. | In large volume, they can dilate arteries.

Question 85

What is active hyperaemia? In what vessels does this occur?

Answer 85

when changes to oxygen and carbon dioxide metabolites cause dilation of arteries.

Question 86

When is reactive hyperaemia induced?

Answer 86

When there is a temporary blockage in blood flow.