Question

which of the following hormones directly stimulates growth of muscle tissue, leading to increased muscle mass?
testosterone
thyroid hormone
parathyroid hormone
epinephrine
calcitonin

Explanation:

Testosterone is an anabolic hormone that promotes muscle - protein synthesis, directly stimulating muscle tissue growth and increasing muscle mass. Thyroid hormone mainly regulates metabolism. Parathyroid hormone is involved in calcium - phosphate homeostasis. Epinephrine is a stress hormone that prepares the body for the "fight - or - flight" response. Calcitonin helps regulate calcium levels in the blood.

Answer:

testosterone