Biology unit 9

Question 1

Circulatory system #1

Answer 1

• allows us to transport nutrients, waste products and gases
• deoxygenated blood is pumped to the lungs where it is oxygenated and CO2 is removed

Question 2

Our circulatory system #2

Answer 2

• oxygenated blood flows back to the heart and is pumped to body cells
• oxygen diffuses into body cells and co2 diffuses into the blood. The blood then flows back to the heart to repeat the cycle
• this is known as a double circulatory system as there are two circuits.
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Question 3

How heart can be monitored

Answer 3

• using a stethoscope you can listen for if the valves are opening and closing correctly
• using an electrocardiogram (ECG) we can measure the electrical signal from the heart to see if it is contracting in a healthy rhythm.
• measuring beats per min or blood pressure
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Question 4

Three types of blood vessels

Answer 4

Arteries veins and capillaries

Question 5

Arteries

Answer 5

Carry blood away from the heart
Arteries can stretch
You feel this as a pulse
Blood in arteries is under high pressure
Arteries have a small lumen with thick, elastic walls to handle the high blood pressures.

Question 6

Veins

Answer 6

Carry blood back to your heart
Contains valves
Valves prevent back flow of blood
Blood is squeezed back towards the heart by the action of the skeletal muscles
Large lumen and relatively thin walls as blood pressure is lower

Question 7

Capillaries

Answer 7

Form a huge network linking arteries and vein
Allows blood to access every cell in our body
Walls are only 1 cell thick, reducing diffusion distance

Question 8

Double circulatory system in mammals #1

Answer 8

One transport system carries blood from your heart to your lungs and back again
The other transport system carries blood from your heart to all other organ of your body and back again.

Question 9

Animals #2

Answer 9

It makes our circulatory system very effient as oxygenated and deoxygenated blood don’t mix.
More areas of your body will receive oxygenated blood more quickly as blood can be sent off to different parts of the body at a high pressure

Question 10

Blood vessels in the liver

Answer 10

The hepatic artery carries oxygenated blood to the liver
The hepatic vein carries deoxygenated blood back to the heart
The hepatic portal vein carries nutrient rich blood from the intestines to the liver
Hepatic = always liver

Question 11

Blood vessels in the kidneys

Answer 11

Oxygenated blood is carried to the kidneys in the renal artery
Deoxygenated blood is carried back to the heart in the Renal vein
Renal = kidneys

Question 12

4 major components of blood

Answer 12

Red blood cells
White blood cells
Plasma
Platelets

Question 13

Red blood cells

Answer 13

Transport oxygen from the lungs to every cell in the rest of the body

Question 14

White blood cell

Answer 14

Produces antibodies that help to protect against infection and foreign pathogens

Question 15

Coronary heart disease definition

Answer 15

Damage or disease in the heart’s major blood vessels.
The usual cause is the build-up of plaque. This causes coronary arteries to narrow, limiting blood flow to the heart.

Question 16

Coronary heart disease causes

Answer 16

Overweight
Physical inactivity
Unhealthily eating
Smoking tobacco

Question 17

What causes your blood to clot?

Answer 17

Blood clot forms as the bodies ways of stopping bleeding from damaged blood vessels and promote healing usually from an injury or a medical procedure/surgeries.

Question 18

Why is the ability for our blood to clot important?

Answer 18

Blood clotting is important process that prevents excessive bleeding when blood vessel is injured. Platelets and protein in your plasma work together to stop the bleeding by forming a clot over the injury.

Question 19

Explain why the conversion of the protein fibrinogen to fibrin to form a mesh is required for blood clotting

Answer 19

Platelets release chemicals that calls a soluble fibrinogen proteins to convert into insoluble fibrin and insoluble mesh across the wound, trapping red blood cells and therefore forming a clot

Question 20

White blood cells - phagocytes

Answer 20

Phagocytes- surround and kill microorganisms ingest foreign material and remove dead cells

Question 21

White blood cells - lymphocytes

Answer 21

Lymphocytes- responsible for antibody production, direct cell medicated killing of virus - infected and tumour cells, and regulation of the immune response.