innervates superior pharyngeal constrictor muscle. quizlet

Innervates Superior Pharyngeal Constrictor Muscle: A Comprehensive Guide

The pharynx, also known as the throat, is a vital part of our respiratory, digestive, and circulatory systems. It plays a crucial role in breathing, eating, and speaking by forming a continuous muscular passage for air, food, and liquids to travel down from the nose and mouth to the lungs and stomach. One of the key muscles that help achieve this function is the superior pharyngeal constrictor muscle.

Anatomy of the Superior Pharyngeal Constrictor Muscle

The superior pharyngeal constrictor muscle is one of the six muscles that make up the pharynx. It can be divided into two groups: the pharyngeal constrictors and longitudinal muscles. The pharyngeal constrictors are responsible for compressing the lumen of the pharynx, allowing food to pass through, while the longitudinal muscles help to move the food bolus further down the digestive tract.

The superior pharyngeal constrictor muscle is innervated by the pharyngeal plexus and the pharyngeal branch of the vagus nerve (CN X). It has several origins, including the medial base of the styloid process of the temporal bone, the inferior/cartilaginous part of the auditory tube, and the posterior border of the thyroid cartilage. Its insertions include the posterior border of the thyroid cartilage, blending with the contralateral palatopharyngeus muscle.

Functions of the Superior Pharyngeal Constrictor Muscle

The superior pharyngeal constrictor muscle plays a vital role in the swallowing process by compressing the lumen of the pharynx and helping to move food through the digestive tract. It also helps to facilitate speech by regulating the flow of air through the vocal cords.

In addition to its role in swallowing and speaking, the superior pharyngeal constrictor muscle also helps to prevent foreign objects from entering the lungs by compressing the lumen of the pharynx and preventing them from passing through.

The pharynx is a muscular tube that extends behind the nasal and oral cavities until it reaches the voice box (larynx) and the esophagus. It is approximately 12-14 cm or 5 inches long. The pharynx can be divided into three regions: the laryngopharynx, oropharynx, and nasopharynx.

The nasopharynx connects the oral and nasal cavities, allowing a person to breathe through their nose. The pharyngeal plexus receives branches of the vagus nerve (CN X), glossopharyngeal nerve (CN IX), and maxillary nerve (CN V2). The longitudinal muscles include the palatopharyngeus, salpingopharyngeus, and stylopharyngeus muscles.

In conclusion, the superior pharyngeal constrictor muscle is an important part of the pharynx that helps to regulate the flow of air, food, and liquids through the digestive tract. Its innervation by the pharyngeal plexus and pharyngeal branch of the vagus nerve (CN X) allows it to play a crucial role in swallowing and speaking. By understanding the anatomy and functions of this muscle, we can better appreciate its importance in our overall health and well-being.

Innervates superior pharyngeal constrictor muscle. quizlet