Question

Aggregates of lymphoid tissues present in the distal portion of the small intestine are known as
A. Villi
B. Peyer's patch
C. Rugae
D. Choroid plexus

Answer 1

The small intestine is part of the digestive system. It is located between the stomach and large intestine. The small intestine comprises three distinct regions: the duodenum (starting region) Jejunum (midsection) and ileum (distal region or end region).

Complete answer:
Lymphoid tissues are part of the lymphatic system. The lymphatic system is a network of cells. Tissues and organs that help to rid of body waste and other unwanted substances. The primary function is to transport the lymph that contains infection-fighting white blood cells throughout the body. The lymphoid tissues can be primary or secondary lymphoid tissues depending upon its stage of development and maturation of lymphocytes. The primary lymphoid tissues include thymus and bone marrow, while secondary lymphoid tissues include lymph nodes, tonsils, Peyer's patches, skin, spleen, etc.
Villi are present on the wall of the small intestine. It is a finger-like projection. Its function is to increase in the surface area so as to increase the absorption of food.
Peyer's patches are also known as aggregated lymphoid nodules. It is present in the ileum region of the small intestine. This plays an important part by monitoring the intestinal bacteria and also blocking the growth of the unwanted pathogen in the small intestine.
Rugae are irregular folds in the stomach or other part of the body. The gastric rugae help to expand the stomach and other tissue whenever required or after the consumption of food or liquid. The other location of the rugae where it is present - the upper hard part of the mouth (palate), inside the rectum, wrinkles of the scrotum, etc.
Choroid plexus is present in the brain ventricle. It is a type of secretory tissue. It helps in the secretion of CFS (cerebrospinal fluid).

Therefore the aggregate lymphoid tissues present in the distal portion of the small intestine are Peyer's patches. So the correct answer is option B.

Note: The tissues of the lymphoid organs are different from the tissues in another organ system. In lymphoid organs, the tissue is different considerably upon the cell cycle proliferation of lymphocytes. This differentiation and proliferation are done by specialized lymphoid tissue.