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Which of the following has an abundance of lymphoid tissue in the mucosa and submucosa?

A.

Small intestine

B.

Stomach

C.

Large intestine

D.

Esophagus

Answer and Explanation

The Correct Answer is A

A. Small intestine, particularly the ileum, contains Peyer's patches, which are abundant lymphoid tissues in the mucosa and submucosa. These structures are part of the immune system, protecting the body from pathogens in the digestive tract. 

 

B. Stomach: While the stomach has some lymphoid tissue, it does not have as much as the small intestine, specifically the Peyer's patches.

 

C. Large intestine has lymphoid nodules, but it does not contain as much lymphoid tissue as the small intestine. 

 

D. Esophagus has very little lymphoid tissue compared to the small intestine, as its primary function is to transport food rather than participate in immune defense. 


View Related questions

Correct Answer is C

Explanation

A. Fundus is the upper part of the stomach, which does not regulate the flow of contents to the duodenum.

B. Gastric rugae are folds in the stomach lining that allow for expansion but do not regulate the flow of contents to the duodenum.

C. Pyloric sphincter controls the flow of partially digested food (chyme) from the stomach into the duodenum.

D. Antrum is the lower portion of the stomach that helps in mixing and grinding food but does not directly regulate its flow to the duodenum.

Correct Answer is A

Explanation

A. Na+: Sodium (Na+) is the principal cation in the extracellular fluid (ECF), which includes interstitial fluid and blood plasma.

B. Ca2+: Calcium (Ca2+) is important in various bodily functions but is not the principal cation in the ECF. Sodium is more predominant in ECF.

C. Cl-: Chloride (Cl-) is the principal anion in the ECF, not a cation. Sodium is the principal cation.

D. K+: Potassium (K+) is the principal cation in the intracellular fluid (ICF), not the ECF. Sodium is the principal cation in the ECF.