Human Anatomy - Kotsan I. Y. 2009

Splanchnology
Digestive System
Age-related features of the stomach

The Stomach of a newborn is cylindrical or spindle-shaped. The bulging of the fundus and the greater curvature is poorly defined. THE POSITION OF the stomach is nearly vertical; its volume in a newborn is about 50 cm³, length 5 cm, and width

3 cm. During infancy, the shape of the stomach approaches that of a pear. By the end of the first year of life, the length of the stomach reaches 9 cm, its width is 7 cm, and its volume increases to 250–300 cm³. At two years of age, the stomach volume is 490–590 cm³, at three years — 580–680 cm³, and in an adult, it equals 1200–1600 cm³.

The gastric mucosa in a newborn is relatively thick, gastric pits are poorly developed and number up to 200 thousand (compared to more than 4 million in adults). Gastric glands in a newborn are also poorly developed, numbering only about 500 thousand. By two months of age, there are about 1.8 million of them, at two years — 8 million, at six years — 10 million, at fifteen years — 18 million, and in an adult — approximately 35 million.

The muscular coat of the newborn's stomach has all three layers. The longitudinal layer and oblique fibers of this coat are poorly developed. The muscular coat reaches its maximum thickness by the age of 15–20.

The cardiac orifice (cardia) of the newborn's stomach is located at the level of the VIII–IX thoracic vertebrae, while the pyloric orifice is at the XI–XII thoracic vertebrae. As the child grows and develops, the stomach descends, and by the age of 7, in an upright body position, its cardiac orifice is projected between the XI and XII thoracic vertebrae, and the pyloric orifice between the XII thoracic and I lumbar vertebrae. In old age, the stomach descends even further.