- Diverticulum
- A small bulging sac pushing outward from the colon wall is a diverticulum. As a person ages, pressure within the large intestine (colon) causes pockets of tissue (sacs) that push out from the colon walls. The plural is diverticula. Diverticula can occur throughout the colon but are most common near the end of the left side of the colon, the sigmoid colon.
* * *A pouch or sac opening from a tubular or saccular organ, such as the gut or bladder. [L. deverticulum (or di-), a by-road, fr. de-verto, to turn aside]- allantoenteric d. SYN: allantoic d..- allantoic d. an endoderm-lined outpouching of the hindgut representing the primordium of the allantois; in most amniotes, it grows into the extraembryonic celom; in humans, the distal part of the allantoic lumen is rudimentary, not extending beyond the body stalk. SYN: allantoenteric d..- caliceal d. a congenital or acquired distention of a kidney calix that renders it susceptible to calculus formation. SEE ALSO: Fraley syndrome.- cervical d. a d. in the neck derived from retention of part of one of the pharyngeal pouches (endodermal) or branchial grooves (ectodermal) of the embryo.- diverticula of colon diverticula, which are herniations of mucosa and submucosa through or between fibers of the major muscle layer (muscularis propria) of the colon. Usually multiple, it occurs in 50% of western populations above the age of 70, but is much less common in other populations. Can cause bleeding and episodes of severe inflammation. SYN: colonic diverticula.- diverticula of ampulla of ductus deferens [TA] the irregular sacculations of the ampullary part of the ductus deferens near its termination in the ejaculatory duct. SYN: diverticula ampullae ductus deferentis [TA].- duodenal d. a d. of the duodenum, often of large size, that is occasionally found projecting from the duodenum near the duodenal papilla.- epiphrenic d. a d. which originates just above the cardioesophageal junction and usually protrudes to the right side of the lower mediastinum.- false d. a d. of the intestine that passes through a defect in the muscular wall of the gut and thus does not include a layer of muscle in its wall.- hypopharyngeal d. SYN: pharyngoesophageal d..- Kommerell d. not a true d., but a bulblike swelling at the origin of the left subclavian artery due to a remnant of the left fourth aortic arch; associated vascular ring compression syndromes involve persistent right aortic arch; the left subclavian artery may pass behind the esophagus; the d. may be large enough to compress the trachea and esophagus even after the vascular ring has been divided and may need to be resected or affixed to the chest wall or vertebral fascia.- laryngotracheal d. a d. from the floor of the caudal end of the pharynx which gives rise to the epithelium and glands of the larynx, trachea, bronchi, and lungs. Once this d. separates from the foregut, it is referred to as a tube.- Meckel d. the remains of the yolk stalk of the embryo, which, when persisting abnormally as a blind sac or pouch in the adult, is located on the ileum a short distance above the cecum; it may be attached to the umbilicus and, if the lining includes gastric mucosa, peptic ulceration and bleeding may result.- metanephric d. an outgrowth from the caudal portion of the mesonephric duct on either side, which grows cephalodorsally to make contact with the masses of metanephrogenous tissue (nephric blastemas) and give rise to the epithelial lining of the ureter and of the pelvis and the collecting ducts of the kidney.- Nuck d. SYN: processus vaginalis of peritoneum.- pancreatic diverticula the ventral and dorsal endodermal buds from the embryonic foregut that constitute the primordia of the parenchyma of the pancreas.- pharyngoesophageal d. most common d. of the esophagus; a pulsion d. developing between the inferior pharyngeal constrictor and the cricopharyngeus muscle. SYN: hypopharyngeal d., Zenker d..- pituitary d. a tubular outgrowth of ectoderm from the stomodeum of the embryo; it grows dorsad toward the infundibular process of the diencephalon, around which it forms a cuplike mass, giving rise to the pars distalis and pars juxtaneuralis of the hypophysis. SYN: craniopharyngeal canal, hypophyseal pouch, Rathke d., Rathke pocket, Rathke pouch.- pulsion d. a d. formed by pressure from within, frequently causing herniation of mucosa through the muscularis.- thyroid d., thyroglossal d. the endodermal bud from the floor of the embryonic pharynx; the primordium of the parenchyma of the thyroid gland.- tracheobronchial d. the endodermal lung primordium which will give rise to the epithelial lining of the respiratory tract. SYN: lung bud.- traction d. a d. formed by the pulling force of contracting bands of adhesion, occurring mainly in the distal esophagus, from tuberculous hilar or mediastinal lymphadenitis.- urethral d. a saclike outpouching of the urethral wall, either from a congenital defect or, more commonly, as a result of chronic penetrating inflammation.- Zenker d. SYN: pharyngoesophageal d..
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1) an abnormal pouch or sac opening from a hollow organ (as the colon or bladder)2) a blind tube or sac branching off from a cavity or canal of the body <the liver is an anterior \diverticulum of the intestine (Gordon Alexander)>* * *
n. (pl. diverticula)a sac or pouch formed at weak points in the walls of the alimentary tract. They may be caused by increased pressure from within (pulsion diverticula) or by pulling from without (traction diverticula). A pharyngeal diverticulum occurs in the pharynx and may cause difficulty in swallowing. Oesophageal diverticula occur in the middle or lower oesophagus (gullet); they may be associated with muscular disorders of the oesophagus but rarely cause symptoms. Gastric diverticula affect the stomach (usually the upper part) and cause no symptoms. Duodenal diverticula occur on the concave surface of the duodenal loop; they may be associated with dyspepsia and an increased risk of choledocholithiasis, but usually cause few symptoms. Jejunal diverticula affect the small intestine, are often multiple, and may give rise to abdominal discomfort and malabsorption due to growth of bacteria within them. Meckel's diverticulum occurs in the ileum, about 35 cm from its termination, as a congenital abnormality. It may become inflamed, mimicking appendicitis; if it contains embryonic remnants of stomach mucosa it may form a peptic ulcer, causing pain, bleeding, or perforation. Colonic diverticula, affecting the colon (particularly the lowest portion), become commoner with increasing age and often cause no symptoms. However they are sometimes associated with abdominal pain or altered bowel habit (see diverticular disease) or they may become inflamed (see diverticulitis).* * *
di·ver·tic·u·lum (di″vər-tikґu-ləm) pl. divertiґcula [L. divertere to turn aside] a circumscribed pouch or sac of variable size occurring normally or created by herniation of the lining mucous membrane through a defect in the muscular coat of a tubular organ. diverticular adj
Medical dictionary. 2011.
