Asthma Physiology

Question 1

respiratory system

Answer 1

The human respiratory system is a series of organs responsible for taking in oxygen and expelling carbon dioxide. The primary organs of the respiratory system are lungs, which carry out this exchange of gases as we breathe.

Question 2

Anatomy of respiration

Answer 2

The lungs are located on either side of the thorax. The trachea conducts inhaled air into the lungs through the bronchi. The bronchi then divide into smaller and smaller branches (bronchioles).

The bronchioles end in clusters of microscopic air sacs called alveoli. In the alveoli, oxygen from the air is absorbed into the blood. Carbon dioxide, a waste product of metabolism, travels from the blood to the alveoli, where it can be exhaled.

Question 3

Inhalation physiology

Answer 3

1. The intercostal muscles contract, expanding the ribcage up and out.
2. The diaphragm contracts, pulling downwards to increase the volume of the chest.
3. The pressure inside the chest is lowered drawing air into the lungs.

Question 4

Exhaltion physiology

Answer 4

1. The intercostal muscles relax, the ribcage drops inwards and downwards
2. The diaphragm relaxes, moving back upwards, decreasing the volume of the chest.
3. Pressure inside the chest increases and air is forced out.

Question 5

Definiton of asthma

Answer 5

A chronic disorder of the airways that involves a complex interaction of:

1. Chronic inflammation of the bronchi -> narrowing the airway
2. Muscles around the airway contract when irritated causing worsening of symptoms
3. Inflammation causes extra mucus to be produced which further occludes the airway

Question 6

Cause of asthma

Answer 6

No clear cause in development of asthma - likely to be a combination of factors including:
-Genes
-Environment
o Air pollution
o Modern hygiene standards (AKA - The ‘Hygiene Hypothesis’)
o Chlorine in swimming pools