The Circulatory System

Question 1

Red blood cells

Answer 1

🌈carry oxygen around the body.
🌈specialised cell
🌈contain haemoglobin which is rich in iron.
🌈biconcave shape increases surface area for diffusion of oxygen
🌈absence of a nucleus allows for more haemoglobin to be carried in each cell.

Question 2

White blood cells

Answer 2

Defence aginest disease

Question 3

Platelets

Answer 3

Convert fibrinogen to fibrin, causing blood clotting and scab formation

Question 4

Plasma

Answer 4

Transport cell, food molecules, carbon dioxide, hormones and urea.

Question 5

Two functions of white blood cell

Answer 5

🌈lymphocytes - produce antibodies

🌈phagocytes- engulf and digest microorganism - phagocytosis

Question 6

Cell lysis

Answer 6

🌈salts and other chemicals in the plasma keep its concentration stable at a concentration similar to the blood cells.
🌈If red blood cells are placed in water they will take in water by osmosis and burst.
🌈Red blood cells have no cell wall, nothing stoping them swelling and bursting.

Question 7

Artery structure

Answer 7

🌈flow away from heart 
🌈thick wall
🌈no valves 
🌈muscle layer and elastic fibres 
🌈small Lumen

Question 8

Vein structure

Answer 8

🌈flows back to heart
🌈relatively thick wall
🌈valves 
🌈less muscle fibres and few/no elastic fibres 
🌈large lumen

Question 9

Capillary structure

Answer 9

🌈links veins and arteries
🌈one cell thick and permeable allows diffusion, Oxygen and glucose in, carbon dioxide and urea out
🌈no valves
🌈no muscle layer or elastic fibres

Question 10

Why do Arteries contain muscle and elastic fibres?

Answer 10

🌈They expand as the blood is pulsed through (elastic fibres give strength to prevent bursting.)
🌈After the high pressure pulse, the elastic fibres recoil and muscles contract returning the wall to its original size while maintaining some pressure in the blood.
🌈overall effect is smoothing out the blood flow.

Question 11

What is the point large lumen?

Answer 11

Reduces friction and further aids the movement of blood

Question 12

Arteries spec

Answer 12

Carry blood under high pressure away from heart (usually oxygenated blood)

Question 12

Veins spec

Answer 12

Carry (usually deoxygenated) blood under low pressure towards the heart

Question 13

Valves

Answer 13

Maintain the direction of blood flow

Question 14

Capillaries spec

Answer 14

Allow the exchange of material with tissues through permeable walls

Question 15

Flow of blood round the body

Answer 15

Double circulation

Question 16

Benefits of regular exercise

Answer 16

🌈strengthens heart muscle

🌈increased cardiac output when at rest

Question 17

Pulmonary vein def

Answer 17

Carries oxygenated blood from lungs to the heart

Question 18

Aorta

Answer 18

Carries oxygenated blood from heart all around the body

Question 19

Vena cava

Answer 19

Carries deoxygenated blood from the body back to the heart

Question 20

Pulmonary artery

Answer 20

Carries deoxygenated blood from the heart to the lungs

Question 21

Hepatic artery

Answer 21

Carries oxygen and glucose to the liver

Question 22

Hepatic portal vein

Answer 22

Carries digested food eg glucose and amino acid from s intestine to liver

Question 23

Hepatic vein

Answer 23

Carries glucose and amino acid from the liver around the body

C02 from respiration back to heart and lungs

Question 24

Rental artery

Answer 24

Carries blood rich in urea to kidney for excretion

Question 25

Renal vein

Answer 25

Carries purified blood from kidneys to vena cava and CO2 from respiration back to heart and lungs

Question 26

Why does a fit person have a lower pulse rate

Answer 26

Stronger heart and will therefore be able pump more blood with each contraction therefore does not have to pump as often to pump same volume of blood

Question 27

Why does a fit person gave shorter recovery time

Answer 27

Can pump more O2 to their muscles during exercise may not need to respire anaerobically therefore less lactic acid made. Recovery time quicker not need O2 to break down lactic acid