Heart And Circulatory System

Question 1

What are the 3 distinct layers of the heart wall?

Answer 1

Epicardium (outer)
Myocardium (middle)
Endocardium (inner)

Question 2

What separates the right and left ventricle?

Answer 2

Thick interventricular septum

Question 3

What separates the right and left atria?

Answer 3

Thin interatrial septum

Question 4

The right atrium receives what type of blood and from where?

Answer 4

Deoxygenated/venous blood from the superior and inferior vena cava

Question 5

When blood travel from the right atrium to right ventricle, which valve does it pass through?

Answer 5

Tricuspid valve

Question 6

From the right atrium, which valve does the blood travel to and where does it end up?

Answer 6

Pulmonary valve and enters the right and left pulmonary arteries. The deoxygenated blood then travels to the lungs for gas exchange.

Question 7

Where does oxygenated blood enter the heart?

Answer 7

From the lungs, through the left and right pulmonary veins and into the left atrium

Question 8

Which valve connects the left atrium and the left ventricle?

Answer 8

Mitral (bicuspid) valve - oxygenated blood travels through this

Question 9

From the left ventricle, how does the oxygenated exit the heart?

Answer 9

Through the aortic semilunar valve, the aorta, and to the rest of the body

Question 10

What is the cardiac cycle of deoxygenated blood through the heart?

Answer 10

1. Enters through superior and inferior vena cava to the right atrium
2. Deoxygenated blood leaves the right atrium through the tricuspid valve into the right ventricle
3. Blood exists the right ventricle through the pulmonary valve and exists the heart through the left and right pulmonary arteries
4. The deoxygenated blood then travels to the lungs for gas exchange.

Question 11

What is the cardiac cycle of oxygenated blood through the heart?

Answer 11

1. Enters the left atrium through the left and right pulmonary veins
2. Oxygenated blood travels through the mitral (bicuspid) valve into the left ventricle
3. Exists the left ventricle through the aortic semilunar valve into aorta.
4. The oxygenated blood then travels to the rest of the body.

Question 12

What is the period of diastole in the cardiac cycle

Answer 12

A period of relaxation in the cardiac cycle when the heart fills with blood.
80% of blood flows directly through the atria into the ventricles before contraction.

Question 13

What is the systole period in the cardiac cycle?

Answer 13

The phase of contraction of the hearts ventricles, forcing blood out of the heart.

Question 14

Which valve will close during systole of the left ventricle?

Answer 14

Mitral valve will close to prevent back flow into left atrium

Question 15

Which valve will close during systole of the right ventricle?

Answer 15

Tricuspid valve will close to prevent back flow into right atrium

Question 16

Which ventricle has thicker walls and why?

Answer 16

Left ventricle due to the increased pressure required to pump blood to rest of body.

Question 17

Which valve prevents back flow from the aorta into the left ventricle?

Answer 17

Aortic semilunar valve

Question 18

What is pericarditis?

Answer 18

Inflammation of the pericardial sac

Question 19

How many pints of blood does the heart pump 24/7?

Answer 19

8 pints

Question 20

What encloses and protects the heart and forms the wall of the pericardial cavity which contains the pericardial fluid?

Answer 20

Pericardial sac / Parietal pericardium

Question 21

What is the parietal pericardium composed of?

Answer 21

Outer fibrous and inner serous layer

Question 22

Which layer of the parietal pericardium secretes the pericardial fluid and what is its function

Answer 22

Inner serous layer
Pericardial fluid acts to reduce friction as the heart beats

Question 23

Which layer of the heart wall is responsible for contraction?

Answer 23

Myocardium; thick middle layer, composed of thick cardiac muscle

Question 24

What is endocarditis?

Answer 24

Inflammation of the endocardium (smooth inner layer of the wall, lining of heart and internal structures.

Question 25

What can endocarditis be triggered by?

Answer 25

Very rare; but bacteria can enter the blood stream through the mouth and then end up in the heart

Question 26

What connects cardiac muscle cells together?

Answer 26

Intercalated discs

Question 27

What do intercalated discs consist of and what are their functions?

Answer 27

• Fascia adherens and demosomes; hold cardiac muscle cells end to end.
• Gap junctions; allow ions to pass between cardiac muscle cells, transmitting nerve impulses.

Question 28

What do grooved depressions indicate on the surface of the heart?

Answer 28

Partitions between the 4 chambers.
Also contain the cardiac vessels that supply blood to heart wall.

Question 29

In which direction does the blood flow in the veins?

Answer 29

Blood flows towards the heart

Question 30

In which direction does the blood flow within the arteries?

Answer 30

Away from the heart.

Question 31

What are the components of the conduction system of the heart?

Answer 31

Sinoatrial node
Atrioventricular node
Bundle of Hip
Purkinje fibres

Question 32

Where is the Sinoatrial node located?

Answer 32

Right atrium near the superior vena cava opening

Question 33

During diastole what does the Sinoatrial node exhibit?

Answer 33

Spontaneous depolarisation (pacemaker potential)