smooth muscle
The esophagus
The esophagus has two types of muscles. The upper third of the esophagus is composed of striated muscles, while the lower third contain smooth muscles. The muscles in the middle are a mixture of both striated and smooth.
The wavelike contractions of the smooth muscle in the gastrointestinal system are called peristalsis. The purpose of peristalsis is to push boluses of food along the gastrointestinal tract. This is achieved by the waves of contractions in the smooth muscle followed by relaxation of the muscles, pushing the bolus (ball of food) a bit further along the digestive tract with each contraction. These contractions move food or chyme through the esophagus, and intestines. The same contractions also move urine down the ureter to the bladder.
skeletal - proximal 1/3 of esophagus and anus smooth - middle/distal 1/3 of esophagus through rectum
smooth muscles in the wall of the esophagus.
The body of the esophagus is bounded by physiologic sphincters known as the upper and lower esophageal sphincters. The upper sphincter is composed largely of a muscle that is closely associated with the larynx. When relaxed, as it is during swallowing, this muscle pulls the larynx forward and aids in routing food into the esophagus instead of the larynx. The lower sphincter is simply the muscle that surrounds the esophagus just as it enters the stomach. Both the upper and lower sphincter are closed except during swallowing, which prevents constant entry of air from the oral cavity or reflux of stomach contents.
The Esophagus has 9 specific layers, if you are healthy. They are: mucosa, saliva, lamina propria, smooth muscle, papillae, muscularis extenma, striated muscle, and adventa.
By rhythmic movements called peristalsis. They are wavelike contractions of smooth muscle that propel food through the GI tract.
Smooth muscles make up most of the esophagus, but the upper portion also contains some voluntary or skeletal muscle. The muscles move in a wave like pattern to move food down into the stomach through a process called "peristalsis". At the distal end is the lower esophageal sphincter, a ring of smooth muscle that controls movement of food between the stomach and esophagus.
The esophagus is primarily composed of two types of muscle fibers: skeletal muscle and smooth muscle. The upper third contains striated (skeletal) muscle, which allows for voluntary control during swallowing. The middle third is a mix of both muscle types, while the lower third is predominantly smooth muscle, facilitating involuntary peristalsis to move food toward the stomach. This arrangement enables efficient transport of food through the esophagus.
Involutary muscles are muscles that you can not control. Examples are smooth muscle (in the esophagus, iris, intestines, etc) and cardiac muscle.