Join thousands of students who trust us to help them ace their exams!
Multiple Choice
In the endocrine system, the secretion of parathyroid hormone (PTH) is controlled primarily by which factor?
A
Blood calcium ion concentration ()
B
Blood glucose concentration
C
Thyroid-stimulating hormone (TSH) released from the anterior pituitary
D
Adrenocorticotropic hormone (ACTH) released from the anterior pituitary
0 Comments
Verified step by step guidance
1
Understand that the secretion of parathyroid hormone (PTH) is regulated by a feedback mechanism related to calcium levels in the blood.
Recall that PTH is secreted by the parathyroid glands and its primary role is to increase blood calcium ion concentration when it is low.
Identify that the stimulus for PTH secretion is a decrease in blood calcium ion concentration, which is detected by calcium-sensing receptors on the parathyroid cells.
Recognize that other options like blood glucose concentration, TSH, and ACTH are unrelated to the direct regulation of PTH secretion.
Conclude that the primary factor controlling PTH secretion is the blood calcium ion concentration, specifically when it falls below a certain threshold.