Question
Which of the following mechanisms is used by the marked structure to influence neighboring cells?
| A. |
Nerve mediated
|
| B. |
Vein mediated
|
| C. |
Paracrine
|
| D. |
Epithelium to mesothelium transformation
|
Show Answer
|
Correct Answer » C
Explanation
|
|
The islets of Langerhans are clusters of endocrine cells within the pancreas that secrete hormones like insulin, glucagon, somatostatin, and pancreatic polypeptide. These hormones not only act systemically but also locally affect neighboring islet cells through paracrine signaling.
Paracrine mechanism:
-
Hormones secreted by one type of islet cell (e.g., beta cells secreting insulin) influence adjacent cells (e.g., alpha or delta cells) within the islet.
-
This local hormone interaction helps in fine-tuning glucose homeostasis.
Reason to rule out other options:
A. Nerve mediated – While the pancreas has autonomic innervation, this is not the primary mechanism of intercellular communication within the islets.
B. Vein mediated – This would suggest endocrine action, where hormones enter the bloodstream to act on distant targets, not neighboring cells.
D. Epithelium to mesothelium transformation – This refers to embryological tissue transformation and is irrelevant to hormone signaling in islets.
