Question

Differentiate between

a. Inspiratory and expiratory reserve volume

b. Vital capacity and total lung capacity

c. Emphysema and occupational respiratory disorder

Answer 1

a. Definition

$IRV$ refers to the additional volume of air that can be inspired by a person after a forcible inspiration. $ERV$ refers to the additional volume of air that can be expired by a person by a forcible expiration.

Magnitude:

$IRV$ averages to $2500mL$ to $3000mL$ whereas $ERV$ is about $1000mL$ to $1100mL$.

Criteria	$IRV$	$ERV$
Definition	Additional volume of air that can be inspired by a person by a forcible inspiration	Additional volume of air that can be expired by a person by a forcible expiration
Magnitude	$2500mL$ to $3000mL$	$1000mL$ to $1100mL$

b. Definition:

Vital capacity refers to the maximum volume of air that can be inspired by a person after a forced expiration or expired after a forced inspiration. The total volume of air that can be accommodated in the lungs at the end of a forced inspiration is known as total lung capacity.

Formula:

Vital capacity includes expiratory reserve volume ($ERV$), tidal volume ($TV$), inspiratory reserve volume ($IRV$). Total lung capacity includes residual volume ($RV$), expiratory reserve volume ($ERV$), tidal volume ($TV$) and inspiratory reserve volume ($IRV$). It can also be defined as the sum of vital capacity and residual volume.

Criteria	Vital capacity	Total lung capacity
Definition	The maximum volume of air that can be inspired by a person after a forced expiration or expired after a forced inspiration	The total volume of air that can be accommodated in the lungs at the end of a forced inspiration
Formula	Expiratory reserve volume ($ERV$) + Tidal volume ($TV$) + Inspiratory reserve volume ($IRV$)	Residual volume ($RV$) + Expiratory reserve volume ($ERV$) + Tidal volume ($TV$) + Inspiratory reserve volume ($IRV$)

c. Definition:

Emphysema is a lung condition that gets developed by cigarette smoking and inhalation of toxic gases. Occupational Respiratory Disorder is a lung disorder that gets developed due to prolonged exposure to dust in the environment (industries involving stone-breaking or grinding activities).

Effects:

In emphysema, alveolar walls are damaged and elastic tissue is replaced by connective tissue. In ORD, inflammation and proliferation of fibrous tissues take place, thus damaging lungs.

Criteria	Emphysema	Occupational Respiratory Disorder
Definition	Lung condition that gets developed by cigarette smoking and inhalation of toxic gases	Lung disorder that gets developed due to prolonged exposure to dust in the environment (industries involving stone-breaking or grinding activities)
Effects	Alveolar walls are damaged and there is decrease in the respiratory surface	Inflammation and proliferation of fibrous tissues, thus damaging lungs