Question

Describe factors that might influence the vital capacity of a subject. Include a discussion of restrictive vs obstructive factors.

Answer 1

Vital capacity.

• The maximum volume of air that can be expired after a maximum inspiratory effort is called vital capacity(VC).
• The normal value of VC in men is about 4 liters and in women is about 3 liters.
• Factors such as sex,age,body build,medical condition and physical condition can influence a persons vital capacity.
• Lung can reach their maximum capacity in early adulthood and becomes low while age declines.
• In restrictive lung disease decreses in vital capacity is seen
• In obstructive lung siseases like asthma the vital capacity is usually normal or slightly reduced.