A high concentration of estrogen in blood:
A. Causes ovulation
B. Stimulates lactation
C. Inhibits secretion of FSH
D. Is one cause of osteoporosis
Correct answer: A. Causes ovulation
Question Explanation
The question asks what happens when there is a high concentration of estrogen in the blood. Estrogen is a major female sex hormone produced mainly by the ovaries, and it plays an important role in regulating the menstrual cycle, development of secondary sexual characteristics, and bone health. When estrogen levels rise, they influence other hormones and reproductive processes.
Option Descriptions
A. Causes ovulation
This statement is partially correct but not directly true.
Ovulation does not occur only because estrogen is high; instead, a high level of estrogen triggers a surge of LH (Luteinizing Hormone) from the pituitary gland, and LH surge causes ovulation.
So indirectly, high estrogen helps stimulate ovulation but it does not directly cause it.
B. Stimulates lactation
This is incorrect.
Lactation (milk production) is mainly controlled by the hormone prolactin, and milk ejection is controlled by oxytocin. Estrogen actually inhibits lactation during pregnancy by preventing milk secretion until after birth.
C. Inhibits secretion of FSH — Correct Answer
High estrogen levels cause negative feedback on the anterior pituitary gland, which reduces the secretion of FSH (Follicle-Stimulating Hormone).
This is important because after a follicle matures, the body needs to prevent more follicles from developing in the same cycle.
D. Is one cause of osteoporosis
This is incorrect because low estrogen, not high estrogen, is related to osteoporosis.
After menopause, estrogen levels drop sharply, leading to bone loss and increased risk of fractures.
Final Answer: C. Inhibits secretion of FSH