Respiratory System

• Gas exchange between the external atmosphere and the circulatory system of an organism is the primary feature of the respiratory system.
• This exchange combines the oxygenation of blood with the removal of carbon dioxide and other metabolic waste from circulation in humans and other mammals.
• Gas exchange occurs at the molecular level in the alveoli-tiny sacs that are the essential functional part of the lungs.
• The alveolar epithelial tissue is extremely thin and permeable, facilitating the exchange of gas between the air inside the lungs and the blood stream capillaries.
• Air moves due to variations in pressure, where air flows from high-pressure areas to low-pressure areas.
• The key respiratory system organs work primarily to provide oxygen for cellular respiration to body tissues, extract carbon dioxide from the waste product, and help preserve acid-base balance.
• Sections of the respiratory system are also used for non-vital purposes, such as odor detection, voice generation, and stress, such as during childbirth or coughing.

   
• In order to help you breathe, the respiratory system has several different parts that function together.
• Your airways deliver your lungs with air.
• Mouth and nose - Openings that pull air from outside your body into your respiratory system.
• Sinuses - Hollow areas between the bones in your head that help regulate the temperature and humidity of the air you inhale.
• Pharynx (throat) - Tube that delivers air from your mouth and nose to the trachea (windpipe).
• Trachea - Passage connecting your throat and lungs.
• Bronchial tubes - Tubes at the bottom of your windpipe that connect into each lung.
• Lungs - Two organs that remove oxygen from the air and pass it into your blood.
• From your lungs, your bloodstream delivers oxygen to all your organs and other tissues.
• Muscles and bones help move the air you inhale into and out of your lungs.
• Diaphragm - Muscle that helps your lungs pull in air and push it out.
• Ribs - Bones that surround and protect your lungs and heart.
• When you breathe out, your blood carries carbon dioxide and other waste out of the body.
• Alveoli - Tiny air sacs in the lungs where the exchange of oxygen and carbon dioxide takes place.
• Bronchioles - Small branches of the bronchial tubes that lead to the alveoli.
• Capillaries - Blood vessels in the alveoli walls that move oxygen and carbon dioxide.
• Lung lobes - Sections of the lungs – three lobes in the right lung and two in the left lung.
• Pleura - Thin sacs that surround each lung lobe and separate your lungs from the chest wall.