Respiratory system

• The respiratory system is the organs and other parts of your body involved in breathing, when you exchange oxygen and carbon dioxide.
• Inspiration - Intercostal muscles contract and ribs move up and out. Diaphragm contracts and flattens. Chest cavity expands and pressure drops, air rushes into lungs.
• Exhalation - Intercostal muscles relax and ribs move down and in. Diaphragm relaxes and domes up. Chest cavity decreases in volume and increases in pressure, air is forced out.
• Alveoli are tiny air sacs where gas exchange occurs between blood capillaries and alveolar walls.