Final answer:
The Eustachian tube helps equalize pressure in the middle ear and is opened by actions like yawning or swallowing. It ensures that pressure on both sides of the eardrum is balanced, aiding in hearing and balance.
Step-by-step explanation:
The Eustachian tube is a flattened tube which, when opened by actions such as yawning or swallowing, equalizes pressure in the middle ear with the atmospheric pressure. This action helps maintain balance and proper hearing function by ensuring that the pressure on both sides of the eardrum is equal.
The pharynx, which is part of both the respiratory and digestive systems, is key in directing swallowed food and inhaled air to the right passages. The esophagus is a muscular tube connecting the pharynx to the stomach, and during swallowing, the soft palate and uvula close off the nasopharynx while the epiglottis blocks the trachea to ensure that food enters the esophagus and not the respiratory system.
The pharynx is a flattened tube that plays a dual role in both respiration and digestion. It connects the nasal cavity to the larynx for air passage and allows food to pass from the oral cavity to the esophagus. During swallowing, the epiglottis closes over the opening to the larynx to prevent food from entering the respiratory system.
The esophagus, a muscular tube, connects the pharynx to the stomach. It transports food from the pharynx to the stomach for digestion.