Answer: Alpha cells.
- A Beta cells
- B Gamma cells
- C Alpha cells
- D Delta cells
Correct answer: C. Alpha cells
Explanation: Alpha cells of islets of Langerhans produce glucagon (raises blood glucose). Beta cells produce insulin (lowers blood glucose).
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.