Respiratory system

Question 1

Ventilation

Answer 1

The ribs, intercostal muscles and diaphragm all play important roles in ventilation (breathing).

Question 2

Breathing in-

Answer 2

the internal intercostal muscles relax and the external intercostal muscles contract, pulling the ribcage upwards and outwards

the diaphragm contracts, pulling downwards
lung volume increases and the air pressure inside decreases

air is pushed into the lungs

Question 3

Breathing out-

Answer 3

the external intercostal muscles relax and the internal intercostal muscles contract, pulling the ribcage downwards and inwards

the diaphragm relaxes, moving back upwards
lung volume decreases and the air pressure inside increases

air is pushed out of the lungs

Question 4

Gas exchange in the lungs

Answer 4

Gas exchange in the lungs happens in the alveoli. Some of the features of alveoli

Question 5

Inhale

Answer 5

Oxygen- 21%
CO2- 0.04%
Nitrogen-79%

Question 6

Exhale

Answer 6

Oxygen-16%
CO2- 4%
Nitrogen- 79%