Biology

What are the layers of blood from bottom to top?

Red blood cells, platelets, white blood cells, plasma.

How are red blood cells specialised?

Biconcave shape, no nucleus, contain haemoglobin.

What is the function of red blood cells?

Transports oxygen around the body?

How are white blood cells specialised?

They are flexible.

What is the function of white blood cells?

Protects body against disease.

What is the function of platelets?

Helps the blood clot.

What is plasma?

Water with many dissolved substances.

What is the function of plasma?

Carries cells and transports important nutrients.

What is breathing?

Movement of air in and out of the lungs.

What is respiration?

A chemical reaction releasing energy from glucose.

What is the word equation for respiration?

Glucose + oxygen → carbon dioxide + water [+energy]

What is the trachea?

A windpipe with cartilage rings.

What are bronchi?

Two tubes entering the each lung.

What are bronchioles?

Smaller branches of the bronchi.

What are alveoli?

Air sacs for gas exchange.

What does the diaphragm do?

Controls breathing by moving up and down.

What do intercostal muscles do during inhalation?

Contract.

What do the ribs do during inhalation?

Moves up and out.

What does the diaphragm do during inhalation?

Moves down.

What happens to the thorax volume during inhalation?

It increases.

What happens to the pressure during inhalation?

It decreases.

What do the intercostal muscles do during exhalation?

Relax.

What do the ribs do during exhalation?

Moves down and in.

What does the diaphragm do during exhalation?

Moves up.

What happens to the thorax volume during exhalation?

It decreases.

What happens to the pressure during exhalation?

It increases.

What are the adaptations of alveoli for gas exchange?

Good blood supply, large surface area, permeable walls, and moist lining.

Why do alveoli have thin walls?

Short diffusion distance.

Why do alveoli have a large surface area?

Faster gas exchange.

Why do alveoli have a moist lining?

Gases dissolve before diffusing.

Why do alveoli have a good blood supply?

Maintains concentration gradient.