Organisations T2

Question 1

What is the heart made up of?

Answer 1

• Two atria: left and right
• Two ventricles: left and right

Question 2

Where does deoxygenated blood go?

Answer 2

• Deoxygenated blood enters the right atrium of the heart from the body via the vein called vena cava.
• It then passes into the right ventricle.
• The right ventricle passes the blood to the lungs by the pulmonary artery.

Question 3

Where does oxygenated blood go?

Answer 3

• It returns to the left atrium via the pulmonary vein.
• It then drains into the left ventricle.
• Then is pumped through the aorta and this is where it leaves to go around the body.
• This is systematic circulation.

Question 4

How does the heart beat?

Answer 4

• The heart is self - regulating.
• The heart has pacemaker cells in the right atrium, which create electricity.
• These electrical signals cause the muscular walls of the ventricles to contract.

Question 5

Arteries?

Answer 5

• Carries blood away from the heart.
• Thick, muscular walls to carry blood which is under high pressure.
• Small lumen, expands as blood is forced through.

Question 6

Veins?

Answer 6

• They carry blood towards to heart.
• Thinner, less muscular walls as they carry blood under lower pressure.
• Bigger lumen.
• Has valves to prevent backflow of blood.

Question 7

Capillaries?

Answer 7

• Allows diffusion of gases and nutrients from blood to body cells.
• Very thin wall (one cell thick) to provide a short diffusion pathway for exchange of substances.
• Very small lumen to only allow one red blood cell through at a time and increase contact between blood cells and capilary walls.

Question 8

What are the coronary arteries?

Answer 8

• The heart is surrouned by a network of arteries called coronary arteries.
• They supply the muscle of the heart with lots of oxygen and glucose so they respire efficiently.

Question 9

What is coronary heart disease?

Answer 9

• A condition of the heart which involves blockages or the narrowing of blood vessels that supply the heart muscles with blood.
• It can lead to a stroke or a heart attack.

Question 10

How do blockages form in the arteries?

Answer 10

• Blockages happen when when fatty material builds into plaques (atheromas).
• This is called athersclerosis.
• Eventually the plaques get so big and block the artery.

Question 11

What is blood made up of?

Answer 11

• Red blood cells 44%
• Plasma 55%
• Platelets 1%
• White blood cells 1%

Question 12

What do red blood cells do?

Answer 12

• Carry oxygen from the lungs to every cell in the body.

Question 13

What do white blood cells do?

Answer 13

• To fight infection by pathogen and stop diseases.

Question 14

What does plasma do?

Answer 14

• Carries the blood cells and platelets around the body.

Question 15

What do platelets do?

Answer 15

They are broken down parts of cells which can form scabs.