FILL IN EVALUATION FORM

INTRODUCTION

The respiratory system is important in supplying oxygen to the body for the generation of energy. It also plays an important role in maintaining the acid-base balance of the blood by removing carbon dioxide.

There are four key stages involved in the process of respiration:

1. Ventilation (breathing) - the physical process of moving air in to and out of the lungs. This optimises the composition of gas in the alveoli.

Image reproduced from National Lung Health Education Program Permission granted by Dr Tom Petty, NLHEP

 

Air enters the respiratory system primarily through the nose into the nasal cavity. It then passes through the nasopharynx, larynx and trachea.The trachea splits into the left and right bronchi. Each bronchus then branches further into smaller bronchioles. Alveoli, the site of gas exchange between the air in the lungs and the blood, are located at the terminus of the bronchioles. Image reproduced from Asthma, Pharma-CAL-ology Permission granted by Jeff Claudius, British Pharmacological Society

 

2. Gas diffusion across the respiratory membrane between the alveoli and the capillaries surrounding the alveoli (pulmonary capillaries).

Image reproduced from A Look At The Human Body Permission granted by Andrew McGann

 

3. Transport of the respiratory gases in the circulation between the pulmonary capillaries and other tissues.

This figure shows part of the circulatory system. The pulmonary artery takes deoxygenated blood (shown in blue) to the lungs where gas exchange occurs in the capillaries. The pulmonary vein takes now oxygenated blood (shown in red) back to the heart where it is then pumped around the rest of the body, providing O2 to other organs and removing CO2. Image reproduced from Kimball's Biology Pages Permission granted by John W Kimball

4. Exchange of dissolved gases between the blood and tissues.