Answer: Thyroxine, from the thyroid.
- A Insulin, from the pancreas
- B Thyroxine, from the thyroid
- C Glucagon, from the pancreas
- D Oxytocin, from the pituitary
Correct answer: B. Thyroxine, from the thyroid
Explanation: Thyroxine regulates the basal metabolic rate, influencing the metabolism of carbohydrates, proteins and fats in almost all body tissues.
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.