Question

Which phrase best describes the process of ventilation?

A) Downward movement of the diaphragm to allow air to enter the lungs
B) Exchange of oxygenated air and waste gases
C) Transport of oxygen from the outside environment into the alveoli
D) Signal from the brain that initiates the breathing cycle

Answer 1

Ventilation is the process of moving air into and out of the lungs. It involves inhaling and exhaling. Inhaling occurs when the diaphragm contracts and moves downward, while exhaling occurs when the diaphragm relaxes and moves upward.

Step-by-step explanation:

The process of ventilation is the movement of air into and out of the lungs. It involves two steps - inhaling and exhaling. Inhaling is an active process that occurs when the diaphragm contracts and moves downward, creating more space in the thoracic cavity. This increase in volume leads to a decrease in intra-alveolar pressure, causing air to flow into the lungs. Exhaling, on the other hand, is typically a passive process that occurs when the diaphragm relaxes and moves upward, decreasing the volume of the thoracic cavity. This increase in intra-alveolar pressure causes air to flow out of the lungs.