Digestive tract-associated lymphatic tissue includes all of the following except
A) pancreatic islets of Langerhans
B) tonsils
C) Peyer’s patches
D) appendix
The correct answer and explanation is :
The correct answer is A) pancreatic islets of Langerhans.
Explanation:
Digestive tract-associated lymphatic tissue (DALT) is a component of the immune system that plays a crucial role in protecting the body against pathogens that may enter through the digestive system. This type of tissue is primarily composed of lymphoid structures that help in immune responses within the gastrointestinal (GI) tract.
Let’s go through the options:
- Pancreatic islets of Langerhans (A) – The islets of Langerhans are clusters of endocrine cells in the pancreas responsible for secreting hormones like insulin, glucagon, and somatostatin. These structures are not involved in the immune response, making them unrelated to digestive tract-associated lymphatic tissue. They do not contain lymphoid tissue and thus are not part of DALT.
- Tonsils (B) – The tonsils, located in the throat, are part of the body’s lymphatic system and help in trapping pathogens that enter through the mouth and nose. They contain lymphoid tissue and are an important component of the immune system, acting as a defense mechanism against infections. Tonsils are considered part of DALT.
- Peyer’s patches (C) – Peyer’s patches are clusters of lymphoid tissue found in the walls of the small intestine, particularly the ileum. They monitor intestinal bacteria and play an important role in immune responses by producing lymphocytes, which are essential in defending against pathogens. Peyer’s patches are a significant part of DALT.
- Appendix (D) – The appendix is an organ located in the lower right abdomen, and it contains lymphoid tissue. It is thought to play a role in immune function, particularly in storing beneficial bacteria for the gut. The appendix is also considered part of DALT.
In summary, while the tonsils, Peyer’s patches, and appendix are components of digestive tract-associated lymphatic tissue, the pancreatic islets of Langerhans are not, as they are primarily involved in hormone production and do not contribute to immune function in the digestive tract.