We are not alone

In our body and on our skin live a lot of bacteria. On each human cell there are ten bacterial cells. This total of bacteria on and in our body is also called microbiome. Most of these are found in the large intestine: the intestinal flora. In an adult, the intestinal flora consists of 1014 (which are 100,000,000,000,000 bacteria). 99% thereof is strictly anaerobic.

A colon, why?

Human colon | SMZ171 stereomicroscope | Moticam 10

In the large intestine (colon) resorption takes place of the remainders of the digested food and liquid, which makes the stool thicker and makes it gliding by the addition of mucus. The wall of the large intestine consists of the typical layers for the digestive tract: the mucosa, submucosa, muscularis and serosa. The lumen is subdivided by numerous crescent-shaped folds.

Human colon | BA410E PlanAPO 10X | Moticam 10

The mucous membrane of the large intestine is a single layer of thick cylindrical epithelium, which consists of numerous absorptive cells with a brush-like edge, amongst which goblet cells are embedded. The latter do not have a brush-like edge and produce mucus especially at the bottom of the tubular crypts. The crypts are straight tubular and run down from the surface through the mucosa. With the depth, the number of goblet cells increases, while the absorptive cells become flatter and diminish in number. The connective tissue of the lamina propria fills the space between the crypts. The muscularis mucosa is composed of an inner ring and an outer layer of smooth musculature. The submucosa is a loose connective tissue with solitary lymph nodes, larger blood vessels and groups of fat cells.