Final answer:
The pharynx is a shared organ of the respiratory and digestive systems allowing passage of air and food. It ensures that during swallowing, the airway is closed to prevent food entering the respiratory tract. The larynx, or voice box, aids in breathing and voice production by moving the vocal cords apart or together accordingly.
Step-by-step explanation:
The Pharynx and Larynx in the Respiratory and Digestive Systems
The pharynx, commonly referred to as the throat, is a crucial component shared by both the respiratory and digestive systems. This tubular organ serves as a pathway for the movement of both air and food. While the pharynx allows the air to travel from the nasal cavity to the larynx, it also permits swallowed food and liquids to move from the oral cavity to the esophagus. A significant aspect of the pharynx's function is its ability to prioritize swallowing over respiration; when food is ingested, involuntary muscle contractions closely coordinate to close off the airway, ensuring that the food does not enter the respiratory tract.
The larynx, also known as the voice box, is situated below the pharynx and connects to the trachea. It is instrumental in the production of vocal sounds as air passes through the vocal cords. When swallowing occurs, the epiglottis—a flap of elastic cartilage—closes over the larynx's opening to prevent the ingested material from entering the respiratory tract, thereby protecting against choking. The larynx's dual function is not only to facilitate breathing by providing a clear passageway for air but also to aid in producing vocal sounds through the vibration of the vocal cords.