Respiratory System Quiz

Study Notes

The respiratory system is responsible for the process of respiration, which involves breathing, gas exchange, and gas transport.

Pulmonary Ventilation (Breathing): The physical movement of air into and out of the lungs, requiring pressure gradients.
Gas Exchange: Involves gas diffusion, specifically external respiration (between air in lungs and blood in alveoli) and internal respiration (between blood & other tissues).
Gas Transport: Transport of oxygen (O2) and carbon dioxide (CO2) in the blood between the alveolar capillaries and the capillary beds in other tissues.

Lung Volumes are the maximum volume to which a lung can be expanded. They are divided into four non-overlapping volumes:
- Tidal Volume (TV): Volume of air inspired or expired with each breath during normal quiet breathing (approximately 500 ml).
- Inspiratory Reserve Volume (IRV): The extra volume of air that can be inhaled by a maximum inspiratory effort over and above the normal tidal volume (approximately 3000 ml).
- Expiratory Reserve Volume (ERV): The extra volume of air that can be exhaled by a maximum forceful expiration over and above the normal tidal volume (approximately 1000 ml).
- Residual Volume (RV): Volume of air that remains in the lungs after the most forceful expiration (approximately 1200 ml).

Lung Capacities are combinations of two or more lung volumes. They include:
- Inspiratory Capacity (IC): Maximum volume of air that can be inspired after a normal tidal expiration (IC = TV + IRV).
- Expiratory Capacity (EC): Maximum volume of air that can be expired after a normal tidal inspiration (EC = TV + ERV).
- Vital Capacity (VC): Maximum volume of air that a person can expel after the deepest possible inspiration (VC = TV + IRV + ERV). This can be affected by factors like thoracic cavity size, age, strength of respiratory muscles, gravity, pregnancy, and pulmonary diseases.
- Total Lung Capacity (TLC): Volume of air present in the lungs after maximal inspiration (TLC = VC + RV).