Answer: The placenta.
- A The ovary
- B The pituitary
- C The placenta
- D The adrenal gland
Correct answer: C. The placenta
Explanation: The developing placenta secretes hCG, which keeps the corpus luteum active so it continues making progesterone.
The hypothalamus releases hormones that direct the pituitary, which releases its own trophic hormone to a target gland; that gland's hormone output then feeds back (dashed lines) to suppress both the pituitary and hypothalamus once levels are sufficient - a self-correcting loop running the entire endocrine system.
Concept context
The endocrine glands, hormone classification and mechanism of action, and negative feedback regulation.