Upper Respiratory Tract:
* Nose: The entry point for air, filtering and warming it with tiny hairs (cilia) and mucus.
* Nasal Cavity: Passageway that connects the nose to the pharynx.
* Pharynx (Throat): A muscular tube that carries air from the nasal cavity to the larynx and food from the mouth to the esophagus.
* Larynx (Voice Box): Contains the vocal cords, responsible for speech, and acts as a valve to prevent food from entering the trachea.
* Epiglottis: A flap of cartilage that covers the trachea during swallowing to prevent food or liquid from entering the lungs.
Lower Respiratory Tract:
* Trachea (Windpipe): A tube lined with cilia and mucus that carries air to the lungs.
* Bronchi: Two branches that split from the trachea and lead to the lungs.
* Bronchioles: Smaller branches that extend from the bronchi, leading to the alveoli.
* Alveoli: Tiny air sacs in the lungs where gas exchange occurs; oxygen diffuses into the bloodstream and carbon dioxide diffuses out.
* Lungs: Two spongy organs responsible for gas exchange, contained within the chest cavity.
Supporting Structures:
* Diaphragm: A dome-shaped muscle that separates the chest cavity from the abdomen. It plays a crucial role in breathing by contracting and relaxing.
* Intercostal Muscles: Muscles between the ribs that help expand and contract the chest cavity during breathing.
Other Important Considerations:
* Mucus: A sticky substance that traps foreign particles and pathogens, preventing them from entering the lungs.
* Cilia: Hair-like structures that line the respiratory passages and move mucus and trapped particles upward, away from the lungs.
The respiratory system is essential for life, providing the body with oxygen and removing carbon dioxide. Any disruption to its function can have serious health consequences.
