ventilation

Question 1

How does gravity affect lung ventilation in an upright subject?

Answer 1

The apices of the lungs are ventilated less efficiently than the bases due to gravity.

This is because the base of the lung undergoes a larger volume change during ventilation than the apex.

Question 2

What happens to lung ventilation when a subject lies on their back?

Answer 2

The posterior regions of the lung become the best ventilated.

This change in ventilation pattern is due to the repositioning of gravity’s effect on lung regions.

Question 3

Define chronic obstructive pulmonary diseases (COPD).

Answer 3

Diseases that interfere with movement of air through the airways.

COPD includes conditions like emphysema and chronic bronchitis.

Question 4

What characterizes asthma?

Answer 4

Short term episodes of broncho-constriction.

These episodes can severely reduce airflow along the airways, leading to difficulty in breathing.

Question 5

What is the principal feature of asthma?

Answer 5

Broncho-constriction.

This constriction can cause significant breathing difficulties during episodes.

Question 6

What does emphysema involve?

Answer 6

Destruction of supporting structures in the lung, leading to airway collapse.

This condition results in trapped air in the alveoli and over-inflation of the lungs.

Question 7

Fill in the blank: In an upright subject, the _______ of the lungs are ventilated less efficiently than the bases.

Answer 7

apices

Question 8

True or False: In COPD, air movement through the airways is enhanced.

Answer 8

False

COPD is characterized by obstructed airflow.

Question 9

Fill in the blank: Emphysema leads to the _______ of airways.

Answer 9

collapse