The anatomical term teenae refers to the annular muscle strips along the mid-colon and appendix that give the intestine its segmented appearance in the first place, grouping the outpouchings of the colon wall into individual rows. In the intestine, humans have a total of three taenia, which play a role in particular in the stability of the intestinal wall and the peristalsis of the colon. Like all other muscles of the body, taenias can be affected by the well-known muscle disorders, although this phenomenon is extremely rare.
What is teenae?
A taenia is a longitudinal muscular strengthening of the large intestine that occurs in humans and some other mammals. In particular, horses, pigs and rabbits, and guinea pigs, in addition to humans, are equipped with taenia. The reinforcements are strand-like to ribbon-like in shape and lie on the longitudinal muscle layer of the colon wall. Because they are somewhat shorter than the rest of the intestinal wall, portions of the intestinal wall sag out to the sides of the taenia. The reinforcements thus give the colon its segmented appearance in the first place. In the end, the taeniae group the outpouchings of the colon wall into individual rows. The number of these rows is thus equivalent to the total number of individual taenia. As a rule, humans have exactly three taenia in the colon. More precisely, these three taenia are located in the area of the colon, that is, in the middle colon. The rectal colon, on the other hand, is entirely free of the reinforcements. Apart from the middle colon, however, taeniae also occur in the appendix, where they are called taeniae caeci. In the large intestine, on the other hand, physicians also call the reinforcing bands Taeniae coli.
Anatomy and structure
Taeniae can be of different types and shapes. The so-called taenia libera are freely visible and do not fuse with other parts of the inner intestinal wall. Therefore, they are also called free taenia. Taenia mesocolica, on the other hand, are fused with the mesocolon transversum, i.e. with the mesentery of the middle colon. Taenia omentalis, on the other hand, are fused to the omentum majus, which is the fatty tissue-rich peritoneum on the inner abdominal wall. Partially, the attachment from the smooth linings of the abdominal cavity covers the ring reinforcements. If we speak of covered taenia, then in this case we can also speak of Taenia obtecta. The crescent-shaped annular folds of the large intestine are also called poschen or haustren by the medical profession. They are formed only by the presence of the reinforcing bands and, thanks to the taenia, are subdivided into so-called rows of haunches. The haustra are not rigid structures. They are dynamic and constantly change their shape during digestive activity. This movement is also called peristaltic segmental movement and is essential during digestion. Peristalsis consists in part of the intrinsic rhythm of the musculature, which enables the intestinal contents to move forward. In another part, peristalsis also involves segmentations that allow the intestinal contents to be mixed.
Function and tasks
The colon is subjected to high pressures and forces. In order for it to withstand these effects intact, it requires stability. Stabilization is therefore among the most important tasks of the taenia. They keep the colon wall architecturally stable and contribute to intestinal peristalsis, i.e. the muscular activity of the colon. They are thus also irreplaceable for general digestion. In addition, the taenia take on the role of a mesentery attachment site. The mesentery is ever the peritoneal fold that serves as a suspensory ligament on an internal organ, thus connecting the organs to the body wall. For physicians, teenae also play an important role in appendectomy, which is a special appendectomy. At the proximal end of the free taenia lies the appendix of the appendix, which has to be removed during appendectomy. The operating physician therefore finds the appendix to be removed all the more easily by following the taenia during the procedure. Thus, in addition to its internal and functional roles in the body, the taenia structure has a guiding structural role externally during appendectomy.
Diseases
Although complaints and diseases of the taenia are extremely rare, they can occur at times. When the taenia is injured or otherwise impaired in function, the bowel wall loses stability and the peristalsis of the bowel is compromised.Functional impairment of the taenia can thus lead to discomfort throughout the gastrointestinal tract resulting from digestive problems. The taenia are primarily muscles. Like all other muscles in the body, they can therefore be affected by typical muscle complaints. For example, any muscle in the body can hurt. In addition to tension, any muscle in the body can also be affected by overuse injuries. Since the load on the tenae is automatic and cannot be triggered mechanically, an overload of the tenae hardly ever occurs, but is still within the realm of possibility in special cases. Muscle inflammation can also occur and, because of its protected position, affects the taenia more frequently than injury, for example. The colon is also frequently affected by tumors. Malignant cancer of muscle is called soft tissue sarcoma and can occur in the taenia in some circumstances. If a tumor spreads to other parts of the body, it may also affect all areas of the colon in one episode.
Typical and common colon diseases
- Crohn’s disease (chronic inflammatory bowel disease)
- Inflammation of the intestine (enteritis)
- Intestinal polyps
- Intestinal colic
- Diverticula in the intestine (diverticulosis)
