Ventilation

Question 1

What is ventilation?

Answer 1

The mechanism of breathing which involves the diaphragm and antagonistic interactions between the external and internal intercostal muscles, bringing about the pressure changes in the thoracic cavity

Question 2

What does ventilation help maintain?

Answer 2

The steep concentration gradient for gas exchange at the alveoli

Question 3

What does the process of inspiration result in?

Answer 3

An increased volume of the thorax and therefore the air pressure in the thorax decreases meaning the air flows into the lungs

Question 4

What does the process of expiration result in?

Answer 4

There’s a decrease in the volume of the thorax and there is an increase in the air pressure within the thorax, forcing air out of the lungs

Question 5

What happens to the diaphragm, external and internal intercostal muscles during inhalation?

Answer 5

Internal intercostal muscles- relax
External intercostal muscle- contract
Diaphragm- contracts

Question 6

What happens to the diaphragm, external and internal intercostal muscles during expiration?

Answer 6

Internal intercostal muscles- relaxes
External intercostal muscle- relaxes
Diaphragm- relaxes

Question 7

When do the internal intercostal muscles contracts?

Answer 7

During forced expiration

Question 8

What stimulates the movement of the diaphragm?

Answer 8

The phrenic nerve

Question 9

Why can expiration be a passive process?

Answer 9

Due to the elastic recoil in the lungs

Question 10

What is a passive process?

Answer 10

Something that doesn’t utilise any energy