Circulatory System - The Heart - diagrams included

Question 1

What does the circulatory system do?

Answer 1

1. Carries food and oxygen to every cell in the body. 2. Carries waste products to where they can be removed from the body.

Question 2

What is the circulatory system made up of?

Answer 2

Heart, blood vessels and blood.

Question 3

What circulatory system do humans have and what is it?

Answer 3

A double circulatory system - two circuits joined together: 1. In first one, right ventricle pumps deoxygenated blood to the lungs to take in oxygen. The blood then returns to the heart.
2. In second one, left ventricle pumps oxygenated blood around all the other organs of the body. The blood gives up its oxygen at the body cells and the deoxygenated blood returns to the heart to be pumped out to the lungs again.

Question 4

What is the heart and what is it made of?

Answer 4

1. It is a pumping organ that keeps the blood flowing around the body. The walls of heart are made of muscle tissue. 2. Has valves to make sure blood flows in the right direction - they prevent it from flowing backwards.

Question 5

How does the heart use its four chambers (right atrium, right ventricle, left atrium and left ventricle) to pump blood around?

Answer 5

1. Blood flows into the two atria (plural of atrium) from the vena cava and the pulmonary vein. 2. The atria contract, pushing the blood into the ventricles. 3. The ventricles contract, forcing the blood into the pulmonary artery and the aorta, and out of the heart. 4. The blood then flows to the organs through arteries and returns through veins. 5. The atria fill again and the whole cycle starts over.

Question 6

How does the heart get its own supply of oxygenated blood that it needs?

Answer 6

Arteries called coronary arteries branch off the aorta and surround the heart.

Question 7

How is your resting heart rate controlled?

Answer 7

1. By a group of cells in the right atrium wall that act as a pacemaker. 2. These cells produce a small electric impulse which spreads to the surrounding muscle cells, causing them to contract.

Question 8

When is an artificial pacemaker used and does it work?

Answer 8

To control heartbeat if the natural pacemaker cells don’t work properly (e.g. if patient has an irregular heartbeat). It produces an electric current to keep the heart beating regularly.