The esophagus wall is composed of striated muscle in the upper part, smooth muscle in the lower part, and a mixture of the two in the middle.
Also, what type of cell is found in the esophagus?
Columnar epithelium, characteristic of the rest of the gut, consists of a single layer of tall, rectangular cells. In Barrett's esophagus, the normally squamous epithelium of the lower esophagus becomes replaced with various types of columnar cells, that may predispose to a type of cancer known as adenocarcinoma.
What makes up the esophagus?
The esophagus is a muscular tube connecting the throat (pharynx) with the stomach. The esophagus is about 8 inches long, and is lined by moist pink tissue called mucosa. The esophagus runs behind the windpipe (trachea) and heart, and in front of the spine. They keep food and secretions from going down the windpipe.
The esophageal wall contains four layers:
- mucosa—surface epithelium, lamina propria, and glands.
- submucosa—connective tissue, blood vessels, and glands.
- muscularis (middle layer) upper third, striated muscle.
- adventitia—connective tissue that merges with connective tissue of surrounding structures.
The muscles in the upper portion of the esophagus are under voluntary control. The remaining portion consists of smooth muscle like the rest of the digestive tract and is not under voluntary control. To keep food from coming back up from the stomach, the esophagus has two circular bands of involuntary muscle.
The mucosa does contain mucous glands that are expressed as foodstuffs distend the esophagus, allowing mucus to be secreted and aid in lubrication. The body of the esophagus is bounded by physiologic sphincters known as the upper and lower esophageal sphincters.
In the case of the respiratory system the major materials moving through it are oxygen and the waste product carbon dioxide. The digestive and respiratory system share some common spaces. The digestive system is composed of the mouth, pharynx, esophagus, stomach, small intestine, large intestine, rectum and anus.
Anteriorly, the esophagus is related to the trachea, right pulmonary artery, left bronchus, pericardium with left atrium, and diaphragm. Posteriorly, the esophagus is related to the vertebral column, right posterior intercostal arteries, thoracic duct, thoracic part of the aorta, and diaphragm.
The esophagus, which passes food from the pharynx to the stomach, is about 25 cm (10 inches) in length; the width varies from 1.5 to 2 cm (about 1 inch). The esophagus lies behind the trachea and heart and in front of the spinal column; it passes through the diaphragm before entering the stomach.
When the esophagus was dilating, the average esophageal wall thickness was between 1.87 and 2.70 mm. The thickest part was cervical esophagus. Thickness of esophageal wall was larger in males than that of females (5.26 mm vs. 4.34 mm p<0.001).
The muscularis propria of the esophagus is unique in that the proximal 1/3 is composed of skeletal muscle, the middle 1/3 is composed of both smooth and skeletal muscle and the distal 1/3 is composed of only smooth muscle. The adventitia is the connective tissue fascia layer that surrounds the esophagus (1).
Signs and symptoms of esophageal cancer include:
- Difficulty swallowing (dysphagia)
- Weight loss without trying.
- Chest pain, pressure or burning.
- Worsening indigestion or heartburn.
- Coughing or hoarseness.
The esophagus is a very long tube that transfers food from the mouth directly to the stomach. But, it also continues digestion. At this point, the food is called a bolus. The bolus moves to the stomach because it is being forced by involuntary muscle contractions within the esophagus continuing mechanical digestion.
Goblet cells reside throughout the length of the small and large intestine and are responsible for the production and maintenance of the protective mucus blanket by synthesizing and secreting high-molecular-weight glycoproteins known as mucins.
After food is chewed into a bolus, it is swallowed and moved through the esophagus. Smooth muscles contract behind the bolus to prevent it from being squeezed back into the mouth. Then rhythmic, unidirectional waves of contractions work to rapidly force the food into the stomach.
The esophagus is about 8 inches long, and is lined by moist pink tissue called mucosa. The esophagus runs behind the windpipe (trachea) and heart, and in front of the spine. Just before entering the stomach, the esophagus passes through the diaphragm.
The stomach produces and secretes several important substances to control the digestion of food. Each of these substances is produced by exocrine or endocrine cells found in the mucosa. The main exocrine product of the stomach is gastric juice — a mixture of mucus, hydrochloric acid, and digestive enzymes.
The esophagus is about 9-10 inches (25 centimeters) long and less than an inch (2 centimeters) in diameter when relaxed. It is located just posterior to the trachea in the neck and thoracic regions of the body and passes through the esophageal hiatus of the diaphragm on its way to the stomach.
The esophageal lining is protected by a stratified squamous epithelium. Because this epithelium is normally not exposed to dryness or to abrasion, it is non-keratinized. A well-developed muscularis provides peristaltic propulsion of food. (Even when upside down, the esophagus can push food and drink to the stomach.)
Oesophageal cancer starts in the food pipe, also known as your oesophagus or gullet. The oesophagus is the tube that carries food from your mouth to your stomach.
The muscular layer of the esophagus has two types of muscle. The upper third of the esophagus contains striated muscle, the lower third contains smooth muscle, and the middle third contains a mixture of both.
The lining of the esophagus is stratified squamous epithelium. Epithelium lines body cavities and surfaces. Stratified squamous epithelium is "stratified" because it is more than one cell layer thick. "Squamous" refers to the fact that the surface cells of the layer are flat.