respiratory system

• Respiratory System is the exchanging of gases (cells and environment). We enhale oxygen and exhale carbon dioxide.
• Upper Respiratory Tract: Nose, nasal cavity, pharynx and the larynx
• Lower Respiratory Tract: Trachea and the lungs: bronchioles, aveoli and bronchi)
• Nose is the only external part. It also serves as the entrance for the air in the body.
• Nostrils are the two openings on the sides of the nose that allows air to enter the nose.
• Nasal cavity is inside the nose. It is where air is filtered, moistened, and warmed by coarse hair, mucous membrane and cilia
• Pharynx is a muscular passage from the nasal cavity to the larynx.
• Pharynx has three regions: nesopharynx, oropharynx, and laryngopharynx
• Epiglottis is a flap tissue that close the entrance to the rest of the respiratory system.
• Larynx is located on top of the windpipe. It connects the pharynx to the trachea and also contains the vocal chords.
• Trachea is a tube-like structure. it has rings of cartilage in the walls to keep air passage open. It is the main passage of our air to the lungs.
• Lungs are the main organs of the respiratory system.
• The alveoli are the site of gas exchange in the lungs. They are surrounded by capillaries.
• Capillaries are one cell thick and have a large surface area to volume ratio. They are also very thin to allow them to be flexible and move around the body.
• The bronchioles are the smallest airways in the lungs. They branch off the bronchi and are lined with ciliated epithelial cells.
• The diaphragm is a muscle that separates the thoracic cavity from the abdominal cavity. It is a large dome-shaped muscle that is located below the lungs and the heart.
• When you inhale, the diaphragm flattens and moves downward, creating more space in the chest cavity and allowing the lungs to expand and fill with air.
• When you exhale, the diaphragm curves upward into a more dome-shaped position—helping to release air from the lungs.