Anatomic and functional maturation of the gastrointestinal tract

Postconceptional age
	20 weeks	25 weeks	30 weeks	35 weeks	40 weeks
Mouth	Salivary glands	Swallow reflex present	Lingual lipase	Sucking reflex present
Esophagus	Muscle layers present	Striated epithelium present	Poor lower esophageal sphincter tone
Stomach	Gastric glands present	G cells appear	Gastric secretions present	Slow gastric emptying	*
Pancreas	Exocrine and endocrine tissue differentiate	Zymogen present	Reduced trypsin, lipase		*
Liver	Lobules form	Bile secreted	Fatty acids absorbed		*
Intestine	Crypts and villi form	Glucose transport present	Dipeptidase, sucrase, and maltase active	Lactase active
Colon		Crypts and villi recede		Meconium passed

Italics indicate functional maturation.

* Full functional maturation occurs postnatally.

Reproduced with permission from: Berseth, CL. Developmental Anotomy and Physiology of the Gastrointestinal Tract. In: Avery's Diseases of the Newborn, 7th ed, Taeusch HW, Ballard RA (Eds), W.B. Saunders Company, Philadelphia, 1998. Table 78-12. Copyright 1998 W.B. Saunders.

Graphic 65282 Version 2.0

خرید پکیج

Anatomic and functional maturation of the gastrointestinal tract