The Heart (T2)

Question 0

What is the average size and weight of an adult human heart?

Answer 0

It is around the size of a clenched fist and weighs 300g

Question 1

What are the three main components of the human cardiovascular system?

Answer 1

• the heart
• the blood
• the blood vessels

Question 2

What is the average adult human heart rate?

Answer 2

70-75 bpm

Question 3

How is the human heart divided into chambers?

Answer 3

The heart is divided into chambers - two up and two down. The top chambers are called the atria and the bottom chambers are the ventricles.

Question 4

How are the top and bottom chambers of the human heart separated?

Answer 4

By valves

Question 5

What is the name of the valve separating the right atrium and the right ventricle?

Answer 5

The tricuspid valve

Question 6

What is the name of the valve between the left atrium and the left ventricle?

Answer 6

The bicuspid valve

Question 7

What is the collective name of the tricuspid and bicuspid valves?

Answer 7

The atrioventricular valves

Question 8

What is the name of the blood vessels arriving at the heart?

Answer 8

The veins

Question 9

What is the name of the blood vessels leaving the heart?

Answer 9

The arteries

Question 10

What are the blood vessels entering the right atrium called?

Answer 10

The superior and inferior vena cavae

Question 11

What is the blood vessel that leaves the right ventricle?

Answer 11

The pulmonary artery

Question 12

What are the blood vessels that enter the left atrium called?

Answer 12

The pulmonary veins

Question 13

How many pulmonary veins are there entering the left atrium?

Answer 13

4

Question 14

What is the name of the blood vessel that leaves the left ventricle?

Answer 14

The aorta

Question 15

What is the collective name of the valves at the base of the aorta and pulmonary arteries?

Answer 15

The semi-lunar valves

Question 16

Which side of the heart contains deoxygenated blood?

Answer 16

The right side

Question 17

Which side of the heart contains oxygenated blood?

Answer 17

The left side

Question 18

What does double circulation in the human heart mean?

Answer 18

Blood flows through the heart twice; pulmonary circulation is the movement of the blood from the heart to the lungs and back to the heart, whilst systematic circulation if the supply of blood from the heart to all the other tissues in the body.

Question 19

What is pulmonary circulation?

Answer 19

The movement of the blood from the heart to the lungs and back to the heart

Question 20

What is systematic circulation?

Answer 20

The supply of blood from the heart to all the other tissues in the body.

Question 21

Do veins carry oxygenated or deoxygenated blood, and what is the exception to this rule?

Answer 21

Veins only carry deoxygenated blood EXCEPT the pulmonary vein.

Question 22

What does the pulmonary vein do?

Answer 22

It takes oxygenated blood from the lungs to the left side of the heart, to be pumped around the rest of the body.

Question 23

Do arteries carry oxygenated or deoxygenated blood, and what is the exception to this rule?

Answer 23

Arteries only carry oxygenated blood EXCEPT the pulmonary artery.

Question 24

What does the pulmonary artery do?

Answer 24

The pulmonary artery takes deoxygenated blood to the lungs.

Question 25

Describe the process of blood flow into and out of the heart…

Answer 25

• blood returns to the right atrium, deoxygenated.
• the right ventricle pumps this blood along the pulmonary artery to the lungs to be oxygenated.
• the oxygenated blood enters the left side of the heart and is pumped out of the aorta to the rest of the body, except the lungs.
• when it reaches the capillaries around the body, oxygen diffuses to the surrounding cells.
• the deoxygenated blood is then carried back to the heart in the veins.
• these join up to form the superior and inferior vena cavae, which are the largest veins in the body.

Question 26

What do you call one complete heart beat?

Answer 26

A cardiac cycle.

Question 27

Define the cardiac cycle in one sentence.

Answer 27

The cardiac cycle is a combination of relaxations (diastole) and contractions (systole) of the heart chambers that occur in sequence.

Question 28

What is the average time for a cardiac cycle in an adult?

Answer 28

Around 0.8s

Question 29

What is the systolic phase (systole) ?

Answer 29

When the ventricles and atria contract.

Question 30

What is the diastolic phase (diastole) ?

Answer 30

The period between contractions, when the ventricles relax and fill with blood.

Question 31

Describe the stages of the cardiac cycle…

Answer 31

RELAXATION (diastole)

• the atria and ventricles are relaxed
• the atrioventricular and semi-lunar valves remain closed
• the ventricle’s volume remains unchanged

RAPID FILLING (diastole)

• the AV valves open
• blood fills both ventricles from their respective atria

SLOWER FILLING (systole)
- the atria contract and force the remaining blood from the atria into the ventricles

CONTRACTION (systole)

• the ventricles contract
• the AV valves are forced shut and for a brief moment the semi-lunar valves are also closed
• the continuing contraction of the ventricles increases the pressure in the ventricles and forces the semi-lunar valves open
• blood is forced out of the ventricles
• blood leaves the right ventricle via the pulmonary artery to the lungs and leave the left ventricle via the aorta to all the other body regions

RELAXATION (diastole)

• the ventricles begin to relax
• blood in the aorta and pulmonary trunk begins to flow backwards, causing the semi-lunar valves to close
• the pulmonary trunk divides into arteries that carry deoxygenated blood to the lungs
• the aorta will carry oxygenated blood to the rest of the body
• the closing of the semi-lunar valves causes a small boost in blood pressure