Which hormone secreted by the anterior pituitary stimulates growth of bones?

• A. Antidiuretic hormone
• B. Growth hormone
• C. Oxytocin
• D. Prolactin

Answer: (B)

Growth hormone is the hormone that stimulates bone growth. It acts on bones directly and also triggers the liver and other tissues to produce IGF-1, which promotes the proliferation of chondrocytes at the epiphyseal (growth) plates and bone formation. This combination drives lengthening of long bones during childhood and adolescence, and helps maintain bone density and muscle mass later in life. The other hormones have different roles: antidiuretic hormone regulates kidney water reabsorption, oxytocin influences uterine contraction and milk let-down, and prolactin stimulates milk production. So growth hormone is the one responsible for stimulating bone growth.