Question

21AOƏ DVIRAL 2. Explain the concept of external respiration in the context of pressure gradients. Toutes should include (but probably not be limited to a graphic showing changes in intra-aivedla pressure through the respiration cycle. I n no 29 telow to 219VOJ DIY 2921719x9 90 dguoni og uoy 26 21609 NOPALVOSG2hon bulmava vit5719251 - 10 noul 911 yitha! 11

Answer 1

Respiration- gaseous exchangement in body.

External respiration- involves exchange of respiratory gases, i.e. oxygen and carbon dioxide between lungs and blood.

It is also called as pulmonary gas exchange.In this,the diffusion of oxygen from air to alveoli of lungs to blood in cappilaries and the diffusion of carbon dioxide to the opposite direction.External respiration in lungs converts deoxygeneted blood coming from the right side of heart into oxygeneted blood that returns to left side of heart

The partial pressure of oxygen in pulmonary cappilaries is 40 mm Hg. and in alveoli, it is 100 mg Hg. The pressure gradient is 64 mm Hg it facilitates the diffusion of oxygen from alveoli into blood.

In atmospheric air potential pressure of carbon dioxide is insufficient and is only about 46 mm Hg where in alveoli it is 40 mm hg. so carbon dioxide enters suggest to blood into alveoli easily.

Intra alveolar pressure

It is the pressure existing in the alveoli of lungs. also known as intra pulmonary pressure.

Intra alveolar pressure is equal to atmospheric pressure, which is 760 mm Hg. It becomes negative during inspiration and positive during expiration.

significance of Intra alveolar pressure

1.  it causes flow of air in and out of alveoli.During inspiration, it become negative , so the atmospheric air enters the alveoli and as it becomes positive during expiration, the air is expelled out of alveoli.

2.it also helps in exchange of gases between alveolar air and the blood.

Inspi- Expiratin Prespiration ration On Intra Alveolar pressure con Pranspulmonary Pressure Intrapleung presse 1 2 3 4 5 1 2 CHANGES IN RESPIRATORY PRESSURES DURING INSPIRATION AND EXPIRATION. 'o' indicates The normal atmospheric pressure (760 mm ty