Upper Arm Muscle - Bicep Muscle Anatomy. There are three major muscle groups in the arm. The biceps brachii is a two headed muscle with point of origin under the deltoid and point of insertion just below the elbow. The basic function of your biceps is to lift and curl the arm, and to also pronate (twist downward) the wrist.
Testosterone is primarily responsible for the development of male secondary sexual characteristics, e.g., beard growth, pubic hair growth, deepening of voice, etc. Testosteron â¦ e.
testosterone. the principal male sex hormone (androgen) that is produced by Leydig's cells of the testes in response to luteinizing hormone secreted by the pituitary gland. It is also produced by the adrenal cortex in both males and females.ale hormone produced by the testes and (in small amounts) in the ovaries. Testosterone is responsible for some masculine secondary sex characteristics such as growth of body hair and deepening voice. Mentioned in: Anabolic Steroid Use, Hormone Replacement Therapy, Klinefelter Syndrome, Menopause, Saw Palmetto.