Biology Component 3

Component 3 - Gaseous exchange in animals and plants, Animal transport

Function of cartilage

provides strength to trachea and bronchus

holds open the airways so there is little resistance

Function of Ciliated epithelium

Cilia on outer membrane of cells moves mucus up the airways towards the mouth.

It is all swallowed and germs are killed by acid in stomach

Function of Goblet cells

Secrete mucus which is a glycoprotein.

Mucus traps particles of dust, bacteria and spores

Function of smooth muscle

Contracts to narrow the airways, which reduces water and heat loss

Function of elastic fibres

Stretch when breathing

Recoil when breathing out to help force air out of lungs

Where can cartilage be found in the gaseous exchange system?

Trachea - rings

Bronchi - blocks

Where can ciliated epithelium be found in the gaseous exchange system?

Trachea

Bronchi

Bronchiole

Where can goblet cells be found in the gaseous exchange system?

Trachea

Bronchi

Bronchiole

Where can smooth muscle be found in the gaseous exchange system?

Trachea

Bronchi

Bronchiole

Where can elastic fibres be found in the gaseous exchange system?

Trachea

Bronchi

Bronchiole

Alveoli

What are the general requirements for efficient gaseous exchange?

Large surface area to volume ratio

Permeable membrane

Thin layer

Moist conditions

Maintaining a concentration gradient

What is a large surface area to volume ratio efficient?

Increases rate of diffusion

Can be achieved by folding of gas exchange surfaces e.g. alveoli in lungs