Gas Exchange

Question 1

What are the key features of a gas exchange surface for efficient diffusion of oxygen and carbon dioxide?

Answer 1

Large surface area for increased diffusion

Thin exchange surface, for a short diffusion distance

Method to maintain a concentration gradient across the exchange surface

Question 2

What is Fix’s law?

Answer 2

Surface area x concentration gradient/ thickness of exchange surface

Question 3

Draw the structure of a chest cavity

Answer 3

Trachea 
Bronchus 
Lung 
Pleural membranes 
Intercostal muscle 
Rib 
Bronchioles

Question 4

What is a goblet cell?

Answer 4

They produce mucus
The mucus traps dust and debris
These cells are found between ciliates epithelial cells of the trachea, bronchi and largest bronchioles

Question 5

What is ciliated epithelium?

Answer 5

Cilia are found on the ciliated epithelium cells of the trachea, bronchi and largest bronchioles
They beat to waft mucus up the trachea

Question 6

What are elastic fibres?

Answer 6

Elastic fibres are found in all the lung tissue, trachea, bronchi, bronchioles, alveoli

Elastic fibres stretch and recoil

This is essential when we exhale

Question 7

What is smooth muscle?

Answer 7

Smooth muscle is not under voluntary control

Found in trachea, bronchi and larger bronchioles
It allows expansion of the airway when we exercise to allow extra air flow

Question 8

Cartilage describe?

Answer 8

C shaped cartilage in the trachea
Rings of cartilage in bronchi or in pieces

Cartilage is strong and flexible. Maintains the shape of the trachea and bronchi and prevents them collapsing when under pressure when you breath in

Question 9

What is squamous epithelium?

Answer 9

The walls of the alveoli are only one cell thick and are made of squamous epithelium
Therefore short diffusion pathway