Question

Succus entericus is secreted by
A. Peyer's patches
B. Crypts of lieberkuhn
C. Auerbach's plexus
D. Brunner’s gland

Answer 1

Complete digestion of the nutrients takes place in the ileum. There are many small glands on the walls of the small intestine. These glands secrete serous fluid. Digestive enzymes in the intestinal fluid break down small peptides into amino acids, disaccharides into monosaccharides, lipids into fatty acids, and glycerol and nucleic acids into nucleotides. The secretion of the intestinal glands is called Succus entricus.

Complete answer:
Let’s first of all understand about all the above options for answering the question.
Peyer’s patches: This is a group of lymph nodes found in the small intestine, especially along the ileum. They produce lymphocytes. Peyer's spots appear in the submucosa located below the inner layer below the epithelial layer of the villi. Each Peyer's plate is a node of 30-40 lymphoid follicles. Like other lymphoid follicles, the follicles forming the Peyer's patch can develop into secondary follicles with an embryonic center.
Crypts of Lieberkuhn- Lieberkuhn crypts are simple tubular structures in the collections between villas. They secrete digestive enzymes and mucus. The mucus is produced by the goblet cells (cells of the mucous membrane), while water and electrolytes are secreted by the intestinal cells of the intestinal crypts. This basement consists of panel and Argentinean chambers.
Auerbach's plexus- Smooth muscles of the stomach arranged in two layers outer longitudinal muscle layer and an inner circular muscle layer. The latter thickens in the sphincter area. Between the two muscle layers is the muscular plexus, or Auerbach's plexus, consisting of sympathetic and parasympathetic fibers.
Brunner's glands- Brunner's glands are found only in the submucosa of duodenum. They secrete enzymes and mucus. The mucus protects the walls of the duodenum from digestion. Most of the nutrients are digested in the duodenum by various enzymes. In Lieberkun's basement, Brunner's glands open.
Now coming to the question
Succus entricus is secreted from the intestine. The intestinal glands are formed by the surface epithelium of the small intestine. These are two types of gland Lieberkun’s and Bruner glands. Succus entericus is mainly produced in the crypt of Lieberkun’s because these glands are found in the small intestine. They secrete digestive enzymes and mucus. Brunner's glands are located only in the duodenum. They secrete mucus and small amounts of enzymes.
So, the correct answer is “Option B”.

Note: About 2000-3000 ml of Succus entericus is released daily which has a pH 7.8.Intestinal juice contains many enzymes such as maltase, isomaltase, sucrase, lactase, α-dextrinase, enterokinase, aminopeptidase, dipeptidase, nucleotidase, nucleosidase, and intestinal lipase.
The small intestine does not secrete enzymes, which means that secretion takes place in the stomach or pancreas. Most of these digestive enzymes are actually intracellular and are only present in sap because the cells are exfoliated. Enteropeptidase and amylase are highly soluble and diffuse and present in succus entericus.