Question

In the colon, constrictions of the wall form a series of small pockets called
(a) Haustra
(b) Crypts of lieberkuhn
(c) Zymogen cells
(d) Taenia

Answer 1

Hint: These small pockets represent mucosal folds inside the colon. They are created by the inner muscular layer of the colon's circumferential contraction. Three parts of the cecum, colon, and rectum distinguish the large intestine.

Complete answer:
- Cecum proceeds into a colon.
- Three bands (taeniae coli) which run from the cecum to the rectum are organized into the outer longitudinal muscular layer.
- In locating the colon inside the peritoneal cavity, these muscular bands, and the elongated serosal fat saccules help.
- Three ribbon- like bands called teniae coli form the longitudinal muscle coat. The pouch- like structure forms in the colon lumen called haustra due to the presence of teniae.
- In a uniform tube called the rectum, which is the holding chamber for feces, the colon then begins.
- The small pouches caused by sacculation (sac formation) , which give the colon its segmented appearance, are the haustra (singular haustrum) of the colon.
- The length of the colon runs along the teniae coli. The colon becomes sacculated between the teniae coli, creating the haustra since the taenia coli is shorter than the colon.
- Haustral contractions are sluggish segmenting movements that occur approximately every 25 minutes and are uncoordinated.
- As it fills with chyme, which stimulates muscles to contract, one haustrum distends, pushing the contents to the next haustrum.
So, the correct answer is ‘Haustra’.

Note:
- In comparison to the circular folds of the small intestine that do, there is a broader gap between haustra than between the circular folds of the small intestine, and haustra do not reach across the entire circumference of the intestine. In an abdominal x- ray, these distinctions may help to differentiate the small intestine from the colon.