GCSE Biology B3

Name 3 ways which solutes can move.

Diffusion, Osmosis and Active Transport.

What route does the oxygen take to get into the blood stream?

Nose to mouth to trachea to to bronchi to bronchioles to alveoli to blood.

What happens when during inhalation?

The intercostal muscles and diaphragm contract (to increase surface area)
The pressure is decreased which draws air into the body.

What adaptations do the alveoli have to maximise diffusion?

A large surface area
Moist (for dissolving gases)
Very thin membrane
A copius blood supply

Where are the Villi and what are their adaptations?

The small intestine.
Large surface area for absorbing food quickly into the blood
A single layer of surface cells
A copious blood supply.