AP BIOLOGY

ANIMAL PHYSIOLOGY

GAS EXCHANGE IN HUMANS

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
Which of the following correctly describes the functioning of the human breathing system?
A
The bronchus cannot change its size.
B
The nasal cavity has hairs to trap dust.
C
The diaphragm muscle contracts during inhalation.
D
The lung expels air through its muscular contraction.
Explanation: 

Detailed explanation-1: -Upon inhalation, the diaphragm contracts and flattens and the chest cavity enlarges. This contraction creates a vacuum, which pulls air into the lungs. Upon exhalation, the diaphragm relaxes and returns to its domelike shape, and air is forced out of the lungs.

Detailed explanation-2: -The lungs and respiratory system allow us to breathe. They bring oxygen into our bodies (called inspiration, or inhalation) and send carbon dioxide out (called expiration, or exhalation). This exchange of oxygen and carbon dioxide is called respiration.

Detailed explanation-3: -This muscle, also called the thoracic diaphragm, plays an important role in breathing as its alternating movement helps you to inhale and exhale. Other diaphragm functions include a role in urination and bowel movements, and assisting the lymphatic system in maintaining lymph flow through the body.

Detailed explanation-4: -The diaphragm plays a critical role in the respiratory system. When you breathe in, your diaphragm contracts (tightens) and flattens, moving down towards your abdomen. This movement creates a vacuum in your chest, allowing your chest to expand (get bigger) and pull in air.

Detailed explanation-5: -The diaphragm helps in the inspiration and expiration of air in and out of the lungs. At the time of inspiration, the diaphragm contracts, increasing the pulmonary volume, thereby reducing the intrapulmonary pressure to less than the atmospheric pressure, and air moves into the lungs.

There is 1 question to complete.