Gas Exchange In Animals

Question 1

Explain tissues of the human exchange system (trachea)

Answer 1

In the trachea- ciliated epithelium cells which contain goblet cells that secrete mucus and trap dust and pathogens, the cilia move in a rhythm to move mucus away from the lungs.

Question 2

Explain tissue in human exchange system ( bronchi I bronchioles)

Answer 2

Smooth muscle cells - control airflow and elastic fibres to stretch and recoil

Question 3

What happens during inspiration?
(breathing in)

Answer 3

• ’ Diaphragm contracts
  -External intercostal muscles relax
• pressure in thorax decreases
  -volume in thorax increases.
• forcing air into the lungs

Question 4

What happens in expiration (breathing out )?

Answer 4

-Diaphragm relaxes
- intercostal muscles contract
- volume in thorax decreases
- pressure in thorax increases
- air is forced out of lungs.

Question 5

What is the alveoli?

Answer 5

• Tiny air sacs in the lungs, the alveolus are wrapped with lots a capillaries.

Question 6

What are three features of alveoli to maximise rate of diffusion?

Answer 6

• Short diffusion pathway -alveolar epithelium only one cell thick.
• large surface area - large number of alveoli
• steep concentration gradient of oxygen and carbon dioxide
• constant ventilation / good blood supply.

Question 7

What is used to analyse lung volume data?

Answer 7

• spirometer

Question 8

What is tidal volume?

Answer 8

• air volume that is breathed in and out in one breath

Question 9

What is vital capacity?

Answer 9

• The maximum air breathed out

Question 10

What is breathing rate?

Answer 10

the amount of breaths per minute.

Question 11

What is oxygen uptake?

Answer 11

• the volume of oxygen used in a given time