SB8d The heart

Question 1

Name all the parts of the heart.

Answer 1

o Atria (left and right)
o Ventricles (left and right)
o Aorta
o Vena cava – inferior and superior vena cava
o Septum
o Valves (semilunar and atrioventricular)
o Pulmonary artery
o Pulmonary vein

Question 2

Describe the Cardiac cycle.

Answer 2

1. The right atrium relaxes and deoxygenated blood coming through the
   vena cava from around the body enters the heart.
2. The right atrioventricular valve opens and blood flows to the right
   ventricle.
3. The blood is then pumped through the pulmonary artery passing by
   the right semilunar valve.
4. Blood reaches the lungs where carbon dioxide is removed and it is
   enriched with oxygen.
5. Oxygenated blood returns to the heart and into the left atrium via the
   pulmonary vein.
6. The left atrioventricular valve opens and blood flows to the left
   ventricle.
7. Blood is pumped with high pressure through the aorta to go to the
   rest of the body

Question 3

Why does the left side of the heart need a thicker wall than the right?

Answer 3

because it needs to withstand more pressure since the blood needs to be pumped to the rest of the body

Question 4

 Why is the heart separated in 2 sides by the septum?

Answer 4

So Oxygenated and Deoxygenated blood don’t mix

Question 5

Define Heart rate

Answer 5

the number of times the heart beats in a minute (beats/
min)

Question 6

Define Stroke volume

Answer 6

Stroke volume = the volume of blood pushed into the aorta in each
beat (liters)

Question 7

Define Cardiac output

Answer 7

the volume of blood pushed into the aorta in each
minute, found by multiplying the stroke volume and the heart rate.

Question 8

When does Coronary hear disease occur?

Answer 8

Coronary heart disease occurs when the coronary arteries that supply the heart with blood become blocked

Question 9

What do organisms need energy for?

Answer 9

o Movement.
o Homeostasis and keeping warm.
o Producing and breaking down substances (metabolism).
o Repair