Respiration and Gas Exchange

Lungs are the primary internal organs responsible for gas exchange and breathing in animals.

Forests are called green lungs because they absorb carbon dioxide and release oxygen during the process of photosynthesis, which is vital for life.

Inhalation is a primary route of pesticide exposure. Chemicals inhaled through the nose or mouth enter the bloodstream through the lungs.

The average resting respiratory rate is about 12 to 20 breaths per minute, with an average tidal volume of about 500 ml, leading to roughly 6 to 10 liters of air per minute.

Asthma is a chronic condition characterized by inflammation and constriction of the bronchioles. Bronchitis is inflammation of the bronchi, while emphysema involves damage to alveoli.

Yeast performs alcoholic fermentation, which releases carbon dioxide as a byproduct. While plants perform cellular respiration, they primarily use aerobic respiration; however, in the context of many biology curricula, yeast is the classic example of an organism that releases CO2 via anaerobic processes.

Alcoholic fermentation, performed by yeast and some bacteria, converts glucose into ethanol and carbon dioxide.

All forms of fermentation and cellular respiration begin with glycolysis, which requires glucose as the primary fuel source to produce energy.

Lactic acid fermentation is named for its primary product, lactic acid, which is produced in animal muscle cells during periods of low oxygen.

The two primary types of fermentation commonly taught in biology are lactic acid fermentation and alcoholic fermentation.

Breathing is the physical act of inhaling and exhaling air. Respiration is the cellular process of using oxygen to break down glucose to release energy.

• Expiration is a mechanism in which air which contains carbon dioxide release out from the lungs of the body.
  
• This air is dry and contains more moisture from the lungs.
• Lungs can never be empty even after force full expiration some amount of air remains in it known as residual volume.
• The exchange of gases occurs only at cellular and alveolar site, not in expiration.
  

During inspiration, the diaphragm contracts and flattens to increase the volume of the the thoracic cavity. This increase in volume leads to a decrease in intra-alveolar pressure, which is a pressure lower than atmospheric pressure and creates the pressure gradient. Due to the gradient the air is from the atmosphere is forced inside the lungs through nasal cavity.

The diaphragm is the muscular organ situated between the thoracic cavity and the abdominal cavity. It contracts and moves downwards due to which the volume in the lungs increases and the air is inhaled. When it relaxes, the volume of the lungs decreases and the air is expelled out.