Gas exchange in humans

Question 1

What gases do humans need and get rid of?

Answer 1

Need oxygen and get rid of carbon dioxide

Question 2

Describe the path of air

Answer 2

Trachea - bronchi - bronchus - bronchioles - alveoli

Question 3

What happens during inspiration?

Answer 3

External intercostals and diaphragm contract. Ribcage moves up and out and diaphragm flattens. Increases volume of thoracic cavity and decreases lung pressure. Air flows in. (active process)

Question 4

What happens during expiration?

Answer 4

External intercostals and diaphragm relax. Ribcage moves in and down and diaphragm curves. Decreases volume of thoracic cavity and increases lung pressure. Air flows out (passive process)

Question 5

Explain the process of gas exchange at the alveoli

Answer 5

Oxygen diffuses out of the alveoli into the haemoglobin
Carbon dioxide diffuses out in the haemoglobin into the alveoli
(alveolar epithelium and capillary endothelium)

Question 6

Describe the adaptations of the alveolio

Answer 6

Fast rate of diffusion because:
Think exchange surface
Large surface area
Moist
Large capillary network
Steep concentration gradient
High SA:V ration

Question 7

Define tidal volume

Answer 7

volume of air in each breathe

Question 8

Define ventilation rate

Answer 8

Number of breaths per minute

Question 9

Define forced expiratory volume

Answer 9

Max volume of air that can be breathed out in 1 minute

Question 10

Define forced vital capacity

Answer 10

Max volume of air it it possible to breathe forcefully out of the lungs

Question 11

Name 4 lungs diseases

Answer 11

Pulmonary tuberculosis
Fibrosis
Asthma
Emphysema