Gas exchange - ventilation

Question 1

What is the primary role of ventilation in the lungs?

Answer 1

Effective exchange of gases in the lungs

Ventilation is essential for maintaining the concentration gradient of oxygen and carbon dioxide.

Question 2

What two processes are involved in ventilation?

Answer 2

Inspiration and expiration

These processes facilitate the movement of air in and out of the lungs.

Question 3

What happens during the inspiration process?

Answer 3

Volume of the chest increases and air pressure decreases

This allows air to rush into the lungs due to the pressure gradient.

Question 4

What causes the air to move into the lungs during inspiration?

Answer 4

Air moves down the pressure gradient from high to low pressure

Gas particles spread out in a larger volume container, reducing pressure.

Question 5

What muscle primarily contracts during inspiration?

Answer 5

Diaphragm

The diaphragm flattens, increasing chest volume.

Question 6

What is the role of external intercostal muscles during inspiration?

Answer 6

Contract to move the ribcage upwards and outwards

This action further increases the volume of the chest.

Question 7

What occurs during expiration?

Answer 7

Volume of the chest decreases and pressure increases

This causes air to be forced out of the lungs.

Question 8

Is expiration mainly an active or passive process?

Answer 8

Passive process

It occurs due to the recoil of the lungs after stretching.

Question 9

What happens to the diaphragm during passive expiration?

Answer 9

It relaxes and becomes dome-shaped

This contributes to the decrease in chest volume.

Question 10

What muscles relax during passive expiration?

Answer 10

External intercostal muscles

This allows the ribcage to move down and in.

Question 11

What can cause expiration to become an active process?

Answer 11

Need to expel excess air from the lungs

For example, when blowing out a candle.

Question 12

What muscles contract during active expiration?

Answer 12

Internal intercostal muscles and abdominal muscles

These actions help to decrease the volume of the chest cavity.

Question 13

Fill in the blank: During inspiration, the diaphragm _______.

Answer 13

contracts and flattens

Question 14

True or False: Expiration only occurs through active processes.

Answer 14

False

Expiration is mainly passive but can be active when needed.