Hey all AIPMT Aspirants, in this Study Material we will learn about PHARYNX and ESOPHAGUS.
It is a funnel-shaped tube that extends from the internal nares to the esophagus posteriorly and to the larynx anteriorly. Also called as Throat.
• It serves as a common passage for food and air. The esophagus and the trachea (wind pipe) open into the pharynx.
• The pharynx is composed of skeletal muscle and lined by mucous membrane.
• It is divided into three parts: Nasopharynx, Oropharynx, and Laryngopharynx.
• Nasopharynx functions only in respiration, but both oropharynx and laryngopharynx have digestive as well as respiratory functions.
• Swallowed food passes from the mouth into the oropharynx and laryngopharynx; the muscular contractions of these areas help propel food into the esophagus and then into the stomach.
• A cartilaginous flap called Epiglottis prevents the entry of food into the glottis (opening of the wind pipe,Trachea) during swallowing.
Esophagus is a long collapsible muscular tube that lies posterior to the trachea.
• It begins at the inferior end of the laryngopharynx, and enters the mediastinum anterior to the vertebral column. It pierces the diaphragm through an opening called the Esophageal hiatus and ends in stomach.
• At each end of the esophagus, Two sphincters are present—Upper Esophageal Sphincter, which consists of skeletal muscle, and the Lower Esophageal (Cardiac) Sphincter, which consists of smooth muscle and is near the heart.
• Upper esophageal sphincter regulates the movement of food from the pharynx into the esophagus; Lower esophageal sphincter/Cardiac sphincter regulates the movement of food from the esophagus into the stomach.