Final answer:
The 2nd pharyngeal arch contributes to the formation of the palatopharyngeal arch in humans and plays a key role in facial and neck development. It also aids in swallowing by directing food to the esophagus and helps in the development of structures essential for hearing and safe ingestion of food.
Step-by-step explanation:
The 2nd pharyngeal arch in human development is crucial for the formation of specific structures within the head and the neck. It plays a significant role in the development of the palatopharyngeal arch, a muscular fold that extends from the lateral side of the soft palate to the side of the pharynx and contributes to the shaping of the facial and neck anatomy.
The pharynx has three subdivisions: the nasopharynx, oropharynx, and laryngopharynx, each serving important functions in respiration and digestion. The oropharynx is the part of the pharynx that is continuous with the oral cavity. During swallowing, various structures including the palatopharyngeal arch help direct the food away from the airways and towards the esophagus.
In addition to this, the elements derived from the pharyngeal arches in vertebrates, like the bones of the middle ear and the epiglottis, are critical for the functions of hearing and preventing food from entering the respiratory tract.