The skin consists of three major cell lineages the

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: cannot be copied, reproduced, manufactured, or disseminated in any form without express written permission from the publisher. © 2009 Sinauer Associates, Inc. UNCORRECTED PAGE PROOFS CELL DEATH AND CELL RENEWAL (A) Surface epithelium Absorptive epithelial cells Cell shedding 19 Goblet Enterocell endocrine cell Crypt Transitamplifying cells Transitamplifying cells Stem cell (B) Surface epithelium Stem cell Crypt FIGURE 17.19 Renewal of the intestinal epithelium (A) Colon epithelial cells are renewed by division of stem cells located at the bottom of the intestinal crypt. The stem cell gives rise to a population of transit-amplifying cells, which occupy about two-thirds of the crypt and undergo three to four divisions before differentiating into the three cell types of the surface epithelium (absorptive epithelial cells, goblet cells, and enteroendocrine cells). The surface epithelial cells continually undergo apoptosis and are shed into the intestinal lumen. (B) Micrograph of a colon crypt a...
View Full Document

This note was uploaded on 08/25/2009 for the course BIO 315 taught by Professor Steiner during the Spring '08 term at Kentucky.

Ask a homework question - tutors are online