Respiratory System and Breathing Process

Study Notes

During breathing, two main processes occur: inhalation and exhalation.
Inhalation begins with the diaphragm moving downward and the sternum outward, creating space in the lungs and allowing air to be sucked in through the nostrils.
Air passes through nostrils hairs that filter out large dust particles, while mucus and cilia remove smaller dust particles and microbes in the nasal cavity.
Mucus also warms and moistens the air as it enters the windpipe, where it is further purified.
Air is divided by bronchi and enters the lungs, where it is further divided by bronchioles and reaches millions of alveoli.
Alveoli, covered with a large number of blood vessels, only allow oxygen to pass into the blood and form oxyhemoglobin.
Oxyhemoglobin then reaches the heart and is pumped to cells throughout the body, where oxygen is used for energy generation and carbon dioxide is produced.
Carbon dioxide is absorbed by the blood and returned to the heart, which pumps it to the lungs for exhalation.
Exhalation occurs when the diaphragm moves inwards and the sternum moves backward, pressurizing gases to be expelled through the nostrils.
The process of breathing is controlled by the brain.

Description

Learn about the respiratory system and the breathing process, including inhalation and exhalation. Understand how air is filtered, warmed, and purified as it travels through the respiratory tract, reaching the alveoli where oxygen is exchanged for carbon dioxide.