Lesson 6 : The Heart

Question 1

pericardium

Answer 1

A double-layered membrane that surrounds and protects the heart. It contains fluid to reduce friction as the heart beats.

Question 2

myocardium

Answer 2

The thick, muscular layer of the heart wall responsible for contracting and pumping blood.

Question 3

endocardium

Answer 3

The inner lining of the heart chambers and valves, providing a smooth surface for blood flow within the heart.

Question 4

atrium

Answer 4

The upper chambers of the heart (left and right) that receive blood returning to the heart from the body or lungs.

Question 5

ventricle

Answer 5

The lower chambers of the heart (left and right) that pump blood out of the heart to the lungs (right ventricle) or to the rest of the body (left ventricle).

Question 6

vena cava

Answer 6

The large veins (superior and inferior vena cava) that bring deoxygenated blood from the body into the right atrium of the heart.

Question 7

pulmonary circulation

Answer 7

The part of the circulatory system that carries deoxygenated blood from the right side of the heart to the lungs and returns oxygenated blood to the left side of the heart.

Question 8

systemic circulation

Answer 8

The part of the circulatory system that carries oxygenated blood from the left side of the heart to the body and returns deoxygenated blood to the right side of the heart.

Question 9

tricuspid valve

Answer 9

The atrioventricular valve between the right atrium and right ventricle, preventing backflow of blood into the atrium during ventricular contraction.

Question 10

atrioventricular valve

Answer 10

Valves (tricuspid and bicuspid/mitral) located between the atria and ventricles that prevent backflow into the atria when the ventricles contract.

Question 11

Bicuspid (mitral) valve

Answer 11

The atrioventricular valve between the left atrium and left ventricle, preventing backflow of blood into the left atrium during ventricular contraction.

Question 12

SA node

Answer 12

The heart’s natural pacemaker located in the right atrium, responsible for initiating electrical impulses that regulate the heartbeat.

Question 13

AV node

Answer 13

A node that receives electrical impulses from the SA node and delays them before passing them to the ventricles, ensuring coordinated contraction between atria and ventricles.

Question 14

Purkinje fibre

Answer 14

Specialized fibers that spread the electrical impulse throughout the ventricles, causing them to contract.

Question 15

Electrocardiogram

Answer 15

A test that records the electrical activity of the heart, displaying waves that represent different phases of the cardiac cycle.

Question 16

systole

Answer 16

The phase of the cardiac cycle during which the heart’s ventricles contract to pump blood out.

Question 17

diastole

Answer 17

the phase of the cardiac cycle during which the heart’s ventricles relax and fill with blood.

Question 18

cardiac cycle

Answer 18

The sequence of events during one heartbeat, including both systole (contraction) and diastole (relaxation)

Question 19

cardiac output

Answer 19

The total volume of blood pumped by the heart per minute, calculated as stroke volume multiplied by heart rate.

Question 20

stroke volume

Answer 20

The amount of blood pumped by one ventricle during a single contraction, usually measured in milliliters per beat.

Question 21

heartbeat

Answer 21

One complete cycle of heart contraction and relaxation, typically producing a “lub-dub” sound as the valves close.