Final answer:
During swallowing, the epiglottis depresses to cover the glottis, laryngeal muscles contract, and the glottis closes to prevent food from entering the respiratory tract, confirming that all the given answers are correct.
Step-by-step explanation:
During swallowing, several actions occur to ensure that food is directed towards the esophagus and not into the respiratory tract. The epiglottis is a flexible piece of cartilage that depresses to cover the glottis, which includes the true and false vocal cords and the space between them. This action blocks the entrance to the trachea. Concurrently, the extrinsic and intrinsic laryngeal muscles contract, lifting the larynx and pulling the epiglottis over the glottis, further ensuring that the food bolus is diverted away from the trachea. The closure of the glottis and elevation of the larynx also prompts a brief cessation of breathing, known as deglutition apnea. The pharyngeal constrictor muscles then contract, moving the bolus through the oropharynx and laryngopharynx, and relaxation of the upper esophageal sphincter allows food to enter the esophagus. The accurate statement concerning the process of swallowing is that all the given answers are correct: the epiglottis is depressed, extrinsic and intrinsic laryngeal muscles contract, and the glottis closes.