Respiratory system

• Alveoli are surrounded by a network of capillaries that allow for the transfer of gases between the alveoli and the bloodstream.
• The bronchi are two tubes that branch off from the trachea into the lungs.
• <S>:The alveoli in the lungs provide a large surface area for oxygen and carbon dioxide exchange.
• Exhalation is the process of expelling carbon dioxide-rich air from the lungs.
• Inhalation is the process of taking in oxygen-rich air into the lungs.
• Oxygen diffuses from the alveoli into the bloodstream while carbon dioxide diffuses from the blood into the alveoli to be exhaled.
• The respiratory system is responsible for breathing, which involves taking air into the body (inhalation) and expelling it back out (exhalation).
• Inspiration is the process of drawing fresh, oxygen-rich air into the lungs.
• Breathing involves both inhalation and exhalation, which occur alternately.
• During inhalation, the diaphragm contracts and moves downward, increasing the volume of the thoracic cavity and causing the lungs to expand.
• The respiratory rate refers to the number of breaths taken per minute, which can vary depending on factors such as age, activity level, and health status.
• During inspiration (inhalation), the diaphragm contracts and moves downward, increasing the volume of the thoracic cavity and decreasing pressure inside it.
• During exhalation, the diaphragm relaxes and returns to its original position, decreasing the volume of the thoracic cavity and causing the lungs to contract.