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![]() The pharyngeal mucosa is lined by both stratified squamous epithelium and ciliated pseudostratified epithelium with goblet cells. Motor and sensory innervation are mainly via branches of the vagus and glossopharyngeal nerves. The lymphatics drain directly into the deep cervical nodes, either directly or through the retropharyngeal or paratracheal nodes. The pharyngeal veins drain into the internal jugular vein. The arterial supply is derived from branches of the external carotid artery, the ascending palatine and tonsillar branches of the facial artery, the maxillary artery, and the dorsal lingual branches of the lingual artery. The pharynx plays a role in deglutition, vocalization, and air conduction. from the uvula to the level of the hyoid bone), and the laryngopharynx (extending approx. from the base of the skull to the soft palate), the oropharynx (extending approx. It is divided into the nasopharynx (extending approx. A focal weakness or deficiency in this area of the pharyngeal wall is termed a Killian dehiscence and can produce a pulsion-pseudodiverticulum, known as a pharyngeal diverticulum or pouch (Zenker diverticulum).The pharynx is a musculomembranous cavity that connects the oral and nasal cavities to the larynx and esophagus. The area of the pharyngeal wall at the junction between the thyropharyngeus and the cricopharyngeus is a potentially weak area. The middle and superior constrictors are enclosed by the thyropharyngeus fibers that wrap around to the midline raphe.The recurrent laryngeal nerve and inferior laryngeal vessels pass upwards deep to the lower border of the cricopharyngeus.It is always closed except for momentary relaxation during swallowing. Its closure prevents air from being sucked into the upper esophagus when intrathoracic pressure falls, allowing air to be sucked only into the permanently open trachea. It is physiologically in a tonic state, constricting the distal end of the pharynx (in coordination with the superior pharyngeal constrictor and the middle pharyngeal constrictor muscles). The cricopharyngeus has an important sphincteric function. ![]() ![]() It acts as a sphincter at the lower end of the pharynx and is always closed except for momentary relaxation during swallowing. Its muscle fibers are continuous with the circular muscular coat of the esophagus. Its fibers run continuously from one side of the cricoid arch to the other side around the pharynx without inserting into a midline raphe posteriorly. The cricopharyngeus muscle is rounder and thicker than the other constrictor muscles. The lower fibers are horizontal and lie edge to edge with those of the cricopharyngeus component. Its fibers curve around posteriorly and insert into the midline raphe. The thyropharyngeus muscle arises from the (a) thyroid cartilage at the oblique line and (b) the tendinous arch that spans the cricothyroid muscle. The inferior pharyngeal constrictor muscle is one of the pharyngeal constrictor muscles. The muscle is described as having two main parts, thyropharyngeus and cricopharyngeus, which originate from the oblique line of the thyroid lamina and lateral aspect of the cricoid cartilage respectively.
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