The Circulatory System

Question 0

Red blood cells

Answer 0

Red blood cells contain haemoglobin which transports oxygen.

Question 1

Plasma

Answer 1

Plasma is the liquid part of blood and it transports chemicals and heat around the body.

Question 2

White blood cells

Answer 2

White blood cells fight infections.

Question 3

Platelets

Answer 3

Platelets help to form blood clots.

Question 4

Arteries

Answer 4

Arteries carry blood away from the heart.

Question 5

Veins

Answer 5

Veins carry blood to the heart.

Question 6

Capillaries

Answer 6

Capillaries allow materials to pass in and out of the bloodstream.

Question 7

Right and left ventricles

Answer 7

The right ventricle pumps blood to the lungs; the left ventricle pumps blood to the rest of the body.

Question 8

The vena cava

Answer 8

The vena cava takes blood low in oxygen from the body to the right atrium.

Question 9

The pulmonary artery

Answer 9

The pulmonary artery takes blood low in oxygen from the right ventricle to the lungs.

Question 10

The pulmonary vein

Answer 10

The pulmonary vein takes oxygen-rich blood from the lungs to the left atrium.

Question 11

The aorta

Answer 11

The aorta takes oxygen-rich blood from the left ventricle to the body.

Question 12

Heart disease

Answer 12

Heart disease is a major cause of illness and death in Ireland. It is mainly caused by small arteries that supply blood to the heart becoming clogged with fat.
The risk of heart disease can be reduced by:
-exercising regularly
-eating a healthy diet (especially by eating less fats and salt)
-not smoking.

Question 13

Excercise

Answer 13

Why we need exercise
When we exercise, the cells in the body (especially in the muscles) need increased supplies of food and oxygen. In addition, the cells need to get rid of extra amounts of carbon dioxide and heat. As a result, exercise causes the heart to beat faster and our pulse rate increases.
Exercise causes us to breathe faster.
Exercise causes the heart to contract more strongly.
Exercise increases the strength of the muscles in our arms and legs and it also increases the strength of our heart.
Exercise helps to reduce weight. This means there is a lower demand for oxygen in the body.

For these reasons some exercise is good for the heart and the circulatory system in general.

Question 14

The heart

Answer 14

• The heart is about the size of a clenched fist. It is located in the left-hand side of the chest.
• The heart is made of a special type of muscle called cardiac muscle. -Cardiac muscle is very strong and does not tire easily.
• The heart contracts in order to pump blood around our body in blood vessels.
• When we are resting, the average rate of an adult heartbeat is 70 beats per minute. When we exercise, the heart beats faster. This causes blood and the materials it carries to move faster around our bodies.

Question 15

Parts of the heart

Answer 15

• Chambers: The heart contains four chambers. The top two are the right and left atrium (plural atria) and the bottom two are the right and left ventricles.
• Septum: The two sides of the heart are separated by a muscular wall called the septum. When a child is born with a hole in the heart, the hole is usually found in the septum.
• Heart valves: Valves in the heart make sure that blood can only flow in one direction. In this way, they are similar to valves in a car tyre or football (which only let air pass in, but not out).