Respiration :-

The steps of respiration involved are the following:-

1. Breathing or pulmonary ventilation by which atmospheric air is drawn in and CO2 alveolar air is released.
2. Diffusion of gases ( O2 and CO2) across the alveolar membrane.
3. Transport of gases by the blood.
4. Diffusion of O2 and CO2 between blood and tissues.
5. Utilisation of O2 by the cells for catabolic reactions and resultant release of CO2 ( cellular respiration).

Divided into 2 parts:-

The part starts with the ( external nostrils up to the terminal bronchioles).

Conducting Part:

1. Conducts
2. Filters air (hair and mucous)
3. Warms air (thermaregul)
4. Humidification (add moisture)

Chief Respiratory Structures:-

Lungs:-

1. Roughly Triangular
2. Non-muscular
3. In paired

Right Lungs:

• Shorter but broader due to liver
• Right Lungs divided into 3 lobes:

1. Superior
2. Inferior
3. Medium

Left Lungs:

• Longer and slender
• 2 Lobes

1. Superior
2. Inferior

Lungs are protected by Ribs/Rib cage and Pleura(2 layers)

Alveoli:

1. Unit of lungs
2. 150 million/lungs
3. Increase the surface area for gaseous exchange
4. Thin walled
5. Highly vascular