What is "intussusception"

Intussusception \In`tus*sus*cep"tion\, n. [L. intus within + susception. Cf. Introsusception.]

1. The reception of one part within another.

2. (Med.) The abnormal reception or slipping of a part of a tube, by inversion and descent, within a contiguous part of it; specifically, the reception or slipping of the upper part of the small intestine into the lower; introsusception; invagination.
   --Dunglison.

3. (Bot.) The interposition of new particles of formative material among those already existing, as in a cell wall, or in a starch grain.

4. (Physiol.) The act of taking foreign matter, as food, into a living body; the process of nutrition, by which dead matter is absorbed by the living organism, and ultimately converted into the organized substance of its various tissues and organs.

   Dead bodies increase by apposition; living bodies by intussusception.
   --McKendrick.

1707, literally "a taking in," from Latin intus "within" (see ento-) + susceptionem "a taking up" (see susceptible).

n. 1 (context rare English) Absorption. 2 (context medicine English) The invagination of one portion of a tubular anatomical structure (especially intestines or blood vessels) within the next.

1. n. the folding in of an outer layer so as to form a pocket in the surface; "the invagination of the blastula" [syn: invagination, introversion, infolding]

2. (biology) growth in the surface area of a cell by the deposit of new particles between existing particles in the cell wall

An intussusception is a medical condition in which a part of the intestine invaginates (folds into) into another section of intestine, similar to the way the parts of a collapsible telescope retract into one another. This can often result in an obstruction. The part that prolapses into the other is called the intussusceptum, and the part that receives it is called the intussuscepiens. Intussusception is a medical emergency and a patient should be seen immediately to reduce risk.

Intussusception also known as splitting angiogenesis, is a type of angiogenesis, the process whereby a new blood vessel is created. By intussusception a new blood vessel is created by splitting of an existing blood vessel in two.

Intussusception was first observed in neonatal rats. In this type of vessel formation, the capillary wall extends into the lumen to split a single vessel in two. There are four phases of intussusceptive angiogenesis. First, the two opposing capillary walls establish a zone of contact. Second, the endothelial cell junctions are reorganized and the vessel bilayer is perforated to allow growth factors and cells to penetrate into the lumen. Third, a core is formed between the two new vessels at the zone of contact that is filled with pericytes and myofibroblasts. These cells begin laying collagen fibers into the core to provide an extracellular matrix for growth of the vessel lumen. Finally, the core is fleshed out with no alterations to the basic structure. Intussusception is important because it is a reorganization of existing cells. It allows a vast increase in the number of capillaries without a corresponding increase in the number of endothelial cells. This is especially important in embryonic development as there are not enough resources to create a rich microvasculature with new cells every time a new vessel develops.

Intussusception may refer to:

• Intussusception (medical disorder)
• Intussusception (blood vessel growth)
• Rectal prolapse#Internal rectal intussusception