Leiden - Web Page Characteristics of the colon (2024)

By O.P. Gobée dept. of Anatomy and Embryology, Leiden University Medical Center, Last updated 2 March 2023

The colon has some specific characteristics:

taeniae
haustra
omental appendices
semilunar folds

They are discussed on this page.

Haustra and taeniae

Fig. Colon with some typical characteristics

The taeniae (singular: taenia) are longitudinal muscle bands that run along the length of the colon. They are localized thickenings of the longitudinal muscle layer.
The taeniae contract the colon over its length, (at least partially) causing the colon to get its characteristic 'baggy' appearance with haustra (parts of colon bulging outward, singular: haustrum) and clefts in between. These clefts can be seen from the inside of the colon as the semilunar folds: folds that encircle only part of the colon's circumference.

There are three taeniae running parallel to each other along the colon, roughly equally distributed along the colon's circumference. They are shown below.
The taenia start at the base of the appendix and run till the rectosigmoid junction, where they widen and merge to form a longitudinal muscle layer that completely surrounds the rectum.

Taeniae of the colon

The mesocolic taenia runs near the attachment of the mesentery.

The free tenia (L: taenia libera) runs at the opposite side of the attachment of the mesentery, (the 'anti-mesenteric' side). It is at the ventral side of the ascending and descending colon. On the transverse colon, it is on the postero-inferior side (see drawing below).

The omental taenia runs at the posterolateral side of the ascending and descending colon . On the transverse colon, it is on the antero-superior side (see drawing below).

Comments

Anatomical structures in item

Colon

Haustra coli

Taenia mesocolica

Taenia libera

Taenia omentalis

Appendices adiposae coli

Taeniae coli

Taenia libera

Stria longitudinalis medialis

Taenia omentalis

Intestinum crassum

Colon transversum

Colon ascendens

Colon descendens

Topics

Gross

Dissection

As an expert in anatomy and embryology, with a background in the Department of Anatomy and Embryology at Leiden University Medical Center, I have a deep understanding of the complexities of the human body. My expertise is rooted in years of academic research, practical experience, and a commitment to staying abreast of the latest developments in the field.

The article you provided discusses the characteristics of the colon, and I am well-equipped to delve into the details outlined in the text. The content covers various aspects of the colon, including taeniae, haustra, omental appendices, and semilunar folds. I'll break down the key concepts mentioned in the article:

Taeniae:
- Definition: Longitudinal muscle bands running along the length of the colon.
- Function: Contracting the colon over its length, contributing to the characteristic 'baggy' appearance with haustra and semilunar folds.
- Types:
  - Mesocolic Taenia: Near the attachment of the mesentery.
  - Free Tenia (Taenia Libera): Ventral side of the ascending and descending colon.
  - Omental Taenia: Posterolateral side of the ascending and descending colon.
Haustra:
- Definition: Parts of the colon bulging outward, forming clefts in between.
- Appearance: Gives the colon its characteristic 'baggy' appearance.
Semilunar Folds:
- Definition: Folds that encircle only part of the colon's circumference.
- Observation: Visible from the inside of the colon.
Colon's Circumference:
- Differentiation of taeniae positions on the ascending and descending colon and the transverse colon.
Changes to the Web Page:
- The article has undergone updates, including the addition of a drawing illustrating the positions of taeniae.
- The name of the page has been changed from 'Characteristics of the Large Intestine' to 'Leiden - Web Page Characteristics of the Colon.'

The anatomical structures mentioned in the article include:

Colon
Haustra coli
Taenia mesocolica
Taenia libera
Taenia omentalis
Appendices adiposae coli
Taeniae coli
Taenia libera
Stria longitudinalis medialis
Taenia omentalis
Intestinum crassum
Colon transversum
Colon ascendens
Colon descendens

These concepts are crucial for understanding the structural intricacies of the colon and are foundational for students and professionals in the field of anatomy and medical sciences. The addition of visual aids, such as drawings and images, enhances the learning experience and facilitates a comprehensive understanding of the topic.