2.1 - Gas exchange

Question 1

What features do mammals have in gas exchange?

Answer 1

Mammals have a small surface area:volume ratio (as they are large).
High metabolic rate.
Lots of 02 needed for respiration.
They are warm.

Question 2

What do Goblet cells produce?

Answer 2

Mucus

Question 3

What do ciliated epithilial cells do?

Answer 3

Waft mucus to the mouth to swallow.

Question 4

What features do alveoli have?

Answer 4

Large surface area:volume ratio.
Thin walls
Large difference in concentration.
Epithelial cells are made of Squamous epithelium

Question 5

What is Fick’s Law equation?

Answer 5

Rate of diffusion ⍺ surface area x difference in concentration /thickness of gas exchange surface

Question 6

The rate of diffusion is proportional to SA because…

Answer 6

There are millions of tiny alveoli and capillaries.

Question 7

The rate of diffusion is proportional to the difference in concentration because…

Answer 7

Breathing in always brings air with a higher oxygen concentration and a lower concentration of carbon dioxide into the alveoli.
Breathing out it always removes air with a lower concentration of oxygen and a higher concentration of carbon dioxide.
The blood in the capillaries is always moving, bringing blood with a higher concentration of carbon dioxide and lower concentration of oxygen.

Question 8

Diffusion is inversely proportional to the thickness of the gas exchange surface because…

Answer 8

The walls of the alveoli and capillaries are one cell thick.

Question 9

How are gills adapted for gas exchange?

Answer 9

Many lamella - large surface area
Thin - short diffusion distance
Countercurrent system