The gastric mucosa is the

mucous membrane A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It ...

layer of the

stomach The stomach is a muscular, hollow organ in the upper gastrointestinal tract of Human, humans and many other animals, including several invertebrates. The Ancient Greek name for the stomach is ''gaster'' which is used as ''gastric'' in medical t ...

, which contains the

gastric pits Gastric pits are indentations in the stomach which denote entrances to 3-5 tubular gastric glands."Secretions from several gastric glands flow into each gastric pit" Principals of Anatomy & Physiology 15th Ed 2017, Gerard Tortora & Bryan Derricks ...

, to which the

gastric glands Gastric glands are glands in the lining of the stomach that play an essential role in the process of digestion. Their secretions make up the digestive gastric juice. The gastric glands open into gastric pits in the mucosa. The gastric mucosa i ...

empty. In humans, it is about one mm thick, and its surface is smooth, soft, and velvety. It consists of simple secretory

columnar epithelium Epithelium or epithelial tissue is a thin, continuous, protective layer of cells with little extracellular matrix. An example is the epidermis, the outermost layer of the skin. Epithelial ( mesothelial) tissues line the outer surfaces of many ...

, an underlying supportive layer of loose connective tissue called the

lamina propria The lamina propria is a thin layer of connective tissue that forms part of the moist linings known as mucous membranes or mucosae, which line various tubes in the body, such as the respiratory tract, the gastrointestinal tract, and the urogenital ...

, and the

muscularis mucosae The muscularis mucosae (or lamina muscularis mucosae) is a thin layer ( lamina) of muscle of the gastrointestinal tract, located outside the lamina propria, and separating it from the submucosa. It is present in a continuous fashion from the esop ...

, a thin layer of muscle that separates the mucosa from the underlying submucosa.

Description

In its fresh state, it is of a pinkish tinge at the

pyloric The pylorus ( or ) connects the stomach to the duodenum. The pylorus is considered as having two parts, the ''pyloric antrum'' (opening to the body of the stomach) and the ''pyloric canal'' (opening to the duodenum). The ''pyloric canal'' ends a ...

end and of a red or reddish-brown color over the rest of its surface. In

infancy In common terminology, a baby is the very young offspring of adult human beings, while infant (from the Latin word ''infans'', meaning 'baby' or 'child') is a formal or specialised synonym. The terms may also be used to refer to juveniles of ...

it is of a brighter hue, the vascular redness being more marked. It is thin at the

cardia The stomach is a muscular, hollow organ in the upper gastrointestinal tract of humans and many other animals, including several invertebrates. The Ancient Greek name for the stomach is ''gaster'' which is used as ''gastric'' in medical terms re ...

c extremity, but thicker toward the pylorus. During the contracted state of the stomach it is thrown into numerous folds or

rugae In anatomy, rugae (: ruga) are a series of ridges produced by folding of the wall of an organ. In general, rugae are a biological feature found in many organisms, serving purposes such as increasing surface area, flexibility, or structural sup ...

, which, for the most part, have a longitudinal direction. They are most marked toward the pyloric end of the stomach, and along the

greater curvature The curvatures of the stomach are the long, convex, lateral surface, and the shorter, concave, medial surface of the stomach, which are referred to as the greater and lesser curvatures, respectively. The greater curvature, which begins at the ca ...

, and are entirely obliterated when the organ becomes distended. When examined with a lens, the inner surface of the mucous membrane presents a peculiar honeycomb appearance from being covered with funnel-like polygonal or hexagonal depressions which vary from 0.12 to 0.25 mm. in diameter. These are the ducts of the

, at the bottom of each may be seen one or more minute openings of the gland tubes. Gastric glands are simple or branched tubular glands that emerge on the deeper part of the

, and outlined by the folds of the mucosa.

Gastric glands

The gastric glands in the cardiac region of the stomach are known as cardiac glands. In the pyloric region the glands are known as pyloric glands, and in the rest of the stomach they are called gastric glands. Several types of endocrine cells are found in the gastric glands. The pyloric glands contain

gastrin Gastrin is a peptide hormone that stimulates secretion of gastric acid (HCl) by the parietal cells of the stomach and aids in gastric motility. It is released by G cells in the pyloric antrum of the stomach, duodenum, and the pancreas. ...

-producing cells (

G cell A G cell or gastrin cell is a type of cell in the stomach and duodenum that secretes gastrin. It works in conjunction with gastric chief cells and parietal cells. G cells are found deep within the pyloric glands of the stomach antrum, and occasi ...

s); this hormone stimulates acid production from the parietal cells.

Enterochromaffin-like cell Enterochromaffin-like cells or ECL cells are a type of neuroendocrine cell found in the gastric glands of the gastric mucosa beneath the epithelium, in particular in the vicinity of parietal cells, that aid in the production of gastric acid via th ...

s (ECLs), found in the oxyntic glands release

histamine Histamine is an organic nitrogenous compound involved in local immune responses communication, as well as regulating physiological functions in the gut and acting as a neurotransmitter for the brain, spinal cord, and uterus. Discovered in 19 ...

, which also is a powerful stimulant of the acid secretion.

Surface

The surface of the mucous membrane is covered by a single layer of

. This epithelium commences very abruptly at the

cardiac orifice The stomach is a muscular, hollow organ in the upper gastrointestinal tract of humans and many other animals, including several invertebrates. The Ancient Greek name for the stomach is ''gaster'' which is used as ''gastric'' in medical terms re ...

, where there is a sudden transition from the stratified epithelium of the

esophagus The esophagus (American English), oesophagus (British English), or œsophagus (Œ, archaic spelling) (American and British English spelling differences#ae and oe, see spelling difference) all ; : ((o)e)(œ)sophagi or ((o)e)(œ)sophaguses), c ...

. The epithelial lining of the gland ducts is of the same character and is continuous with the general epithelial lining of the stomach. The

sodium-iodide symporter The sodium/iodide cotransporter, also known as the sodium/iodide symporter (NIS), is a protein that in humans is encoded by the ''SLC5A5'' gene. It is a transmembrane glycoprotein with a molecular weight of 87 kAtomic mass unit, Da and 13 transmem ...

(SIP) is expressed in all the surface mucous cells (at the basolateral membrane) but not in the mucous neck cells. SIP mediates the transport of

iodide An iodide ion is I−. Compounds with iodine in formal oxidation state −1 are called iodides. In everyday life, iodide is most commonly encountered as a component of iodized salt, which many governments mandate. Worldwide, iodine deficiency ...

from the bloodstream and secretes it into the gastric lumen where it is taken up in the gastric juice. Its role is not known but it has been shown to be absent in gastric cancer.

Pathology

Gastritis Gastritis is the inflammation of the lining of the stomach. It may occur as a short episode or may be of a long duration. There may be no symptoms but, when symptoms are present, the most common is upper abdominal pain (see dyspepsia). Othe ...

Gastric tumor Tumors of the stomach Tumors of the stomach are known as gastric tumors, and can be either benign or malignant (gastric cancer). These tumors arise from the cells of the gastric mucosa which lines the stomach. Typically, most gastric tumors are ...

References

External links

*
Diagram at gerd.com

{{Authority control Abdomen Anatomy Membrane biology Organs (anatomy)