Blood (P1)

Question 1

Arteries

Answer 1

Carry oxygenated blood away from the heart. The pulmonary artery is the only exception as it carries deoxygenated blood

Question 2

Veins

Answer 2

Carry deoxygenated blood towards the heart. The pulmonary vein carries oxygenated blood.

Question 3

Capillary

Answer 3

Gases and nutrients diffuse from the blood to the body cells

Question 4

Artery blood pressure, lumen, walls, other features

Answer 4

• very high blood pressure
• small lumen
• thick and muscular walls with elastic fibres and muscle cells to expand and contract
• thick walls withstand high pressure

Question 5

Vein blood pressure, lumen, walls, other features

Answer 5

• low blood pressure
• large lumen
• thin walls as they aren’t exposed to as much pressure
• valves prevent blood from flowing backwards

Question 6

Capillary blood pressure, lumen, walls, other features

Answer 6

• medium blood pressure
• very small lumen
• walls one cell thick
• made of semi-permeable membranes

Question 7

Red blood cells

Answer 7

Absorbs oxygen
Large surface area, no nucleus
<50% of blood

Question 8

Plasma

Answer 8

Carries suspended blood cells, carries urine, electrolyte, enzymes and nutrients
90% water
50% of blood

Question 9

White blood cells

Answer 9

Defend against pathogens
Surround and ingest 
Antibodies attach to antigen
Release antitoxins that neutralise toxins
<1% of blood

Question 10

Phagocytes

Answer 10

Engulf and destroy pathogens
Large cells
Irregular membranes
Multi-loved nucleus

Question 11

Lymphocytes

Answer 11

Produce antitoxins and antibodies

Huge nuclei

Question 12

Platelets

Answer 12

Fragments of cells with no nucleus
Help the blood to clot at a wound (stop blood pouring out and microorganisms getting in)
<1% of blood