the heart and cardiac cycle

Question 1

how many chambers does the heart have?

Answer 1

4

Question 2

name the chambers of the heart

Answer 2

2 atria, 2 ventricles

Question 3

which side of the heart has oxygenated blood?

Answer 3

left

Question 4

which side of the heart has deoxygenated blood?

Answer 4

right

Question 5

which direction do arteries carry blood?

Answer 5

away from the heart

Question 6

which direction do veins carry blood?

Answer 6

in to the heart

Question 7

what is the term for anything related to the lungs?

Answer 7

pulmonary

Question 8

why is the heart myogenic?

Answer 8

it doesn’t need an electrical impulse from the nervous system to beat. As long as it has a blood supply with oxygen and glucose it will beat independently

Question 9

what is the cardiac cycle?

Answer 9

sequence of events that makes up one heartbeat

Question 10

what are the 3 stages in the cardiac cycle?

Answer 10

atrial systole, ventricular systole, ventricular diastole

Question 11

what is atrial systole?

Answer 11

contraction of atria

Question 12

what is ventricular systole?

Answer 12

contraction of ventricles

Question 13

what is ventricular diastole?

Answer 13

relaxation of ventricles

Question 14

explain the first stage of the cardiac cycle (atrial systole)

Answer 14

the atrium contracts and the AV valve opens so blood is forced into both ventricles. The semi lunar valves are closed. The heart is full of blood. There’s no backflow as the veins have valves.

Question 15

explain the second stage of the cardiac cycle (ventricular systole)

Answer 15

The AV valve closes and the semi lunar valve opens. To allow this, the ventricles contract so pressure increases as volume decreases. Atria contract. Blood flows from ventricles to arteries therefore out of the heart. The atria are relaxing, atrial diastole coincides with ventricular systole
The blood flow to the heart continues, so the relaxed atria begin to fill with blood again

Question 16

explain the third stage of the cardiac cycle (ventricular diastole)

Answer 16

Ventricles relax. AV valve reopens. Valves within the vena cava open. Semi lunar valve closes. Pressure in ventricles reduces. Blood flows from veins into atria and some blood flows into the ventricles. Pressure in the atria rises above that in the ventricles, forcing the AV valves open. The cycle then restarts