Students can go through AP Inter 2nd Year Zoology Notes Lesson 1(b) Breathing and Exchange of Gases will help students in revising the entire concepts quickly.
AP Inter 2nd Year Zoology Notes Lesson 1(b) Breathing and Exchange of Gases
→ Respiration is the vital feature of life.
→ The process leading to, and including the chemical breakdown of food material to provide energy for life is called respiration.
→ External respiration is the exchange of gases between the lungs and blood.
→ Internal respiration is the exchange of gases between the blood and cells of the body.
→ The process of exchange of O2 from the medium with CO2 produced by the cells at the same time is called breathing.
→ Gills are used by aquatic ‘animals and lungs are used by terrestrial forms for the exchange of gases.
→ Human respiratory system consist of external nostrils nasal chambers, nasopharynx, larynx, trachea, bronchi, bronchioles and lungs.
→ Intake of atmospheric air into the lungs is called inspiration.
→ Release of alveolar air to the exterior is called expiration.
→ On average healthy human breaths 12-16 times/minute.
→ A healthy man can inhale (or) exhale approximately 6000 to 8000 ml of air per minute.
→ 97% of O2 is transported by the RBC in the blood.
→ 100 ml of oxygenated blood can deliver 5 ml of O2 to the tissues under normal conditions.
→ 100 ml of deoxygenated blood delivers approximately 4 ml of CO2 to the alveolar air.
→ 70% of CO2 is transported as bicarbonate.
→ Exchange of O2 and CO2 between pulmonary capillaries and alveoli of lungs.
→ Exchange of chloride and bicarbonate ions between erythrocytes and plasma is called chloride shift.
→ Alveoli are thin walled, irregular highly vascularized bag like structure that form the sites of exchange of gases in the lungs.