List of abbreviations
of micros-
specialist terms
explained in
English +

Every attempt was made to provide correct information and labelling, however any liability for eventual errors or incompleteness is rejected!

dieser Seite

Dr. med.
H. Jastrow

of use
Overview colon (Colon):
Pages with explanations are linked to the text below the images if available! (Labelling is in German)
lumen, epithelial cells
colon (rat)
apical cytoplasm
resorbing cells (rat)
microvilli + glykocalix
enterocyte (rat)
base of a crypt with
many goblet cells (rat)
goblet cells, Lamina propria
goblet cell (rat) secretion of a goblet cell
detail thereof: secretion
base of a crypt with 2
enteroendocrine cells (rat)
detail: enteroendocrine cell
Lamina propria mucosae with
connective tissue cells (rat)
idem (rat) 2 plasma cells in the
Lamina propria mucosae (rat)
detail: plasma cell (rat)
--> furter details
other plasma cell of the
Tela submucosa (rat)
Schwann cell of the
Plexus submucosus (rat)

The colon (Terminologia histologica: Colon) is the major part of the large intestine and has a length of 1,3 to 1,5 m and a diameter which is about 3 times that of the small intestine (duodenum, jejunun + ileum). The colon has several segments and begins after the caecum (Terminologia histologica: Caecum in form of the retroperitoneal ascending colon (Colon ascendens). After the right flexure of the colon (Flexura coli dextra) it is followed by the intraperitoneal transverse colon (Colon transversum) which after the left colonic flexure (Flexura coli sinistra) continues as the retroperitoneal descending colon (Colon descendens) to become intraperitoneal in the pelvis as sigmoid (Colon sigmoideum). The rectum finally is the last part of the large intestine.
The colon has 3 longitudinal stripes (taeniae coli;Terminologia histologica: Taeniae coli termed: Taenia libera, - mesocolica & -omentalis) in which the longitudinal layer of the muscularis forms strong bands (see below). Fatty appendages (Appendices epiploicae) are attached to the free taenia (Taenia libera). They mainly consist of loose connective tissue and unilocular fat cells.Haustrae are protrusions of the colon located between incisions visible from outside that from inside appear as semilunar folds of the mucosa (Plicae semilunares). These plicae semilunares are no permanent folds but they disappear when the local contraction of the circular muscle layer which is the cause of their existence diminishes.
The colon (Terminologia histologica: Colon) is characterised by exclusively crypts and a large diameter. Its wall is similar to gut in general but has some specialities. The mucosa has a superficial Lamina epithelialis bordering the lumen with vast amounts of goblet cells, enterocytes and a few enteroendocrine cells at the base of the crypts. The underlying loose connective tissue layer is called Lamina propria mucosae. It shows very large aggregations of secondary lymph follicles that join each other (Folliculi lymphatici aggregati = Payer's plaques), that may reach down in further layers. A thin layer of smooth muscle cells (Lamina muscularis mucosae) is the deepest layer of the mucosa. The following Tela submucosa is a thicker layer of loose connective tissue which shows the submucous nerve plexus (Plexus submucosus; Meissner's plexus) and extends to the following Tunica muscularis. The latter has a circular layer (Stratum circulare) which is very thin in the area of haustres and a logitudinal layer (Stratum longitudinale) which is only evident in the region of taenia. In between these two smooth muscle cell layers the Plexus myentericus (Auerbach-Plexus, a further autonomous nerve plexus of the gut) is encountered. The outermost layer Tunica serosa is a small loose connective tissue layer (Tela subserosa) covered with the monolayered squamous epithelium of the peritoneum only in areas where the colon lies intraperitoneally (e.g., transverse and sigmoid portion). In other (retroperitoneal) regions an adventitia formed by connective tissue anchors the colon to neighbouring structures.

--> Table of enteroendocrine cells
--> ileum, plasma cells
--> Electron microscopic atlas Overview
--> Homepage of the workshop

Images, page & copyright H. Jastrow.