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 is the main sex hormone in men, produced mainly by the testicles, and is responsible for male physical characteristics. Although it is considered to be a male sex hormone, it is present in the blood of both males and females. Typically, a test for total testosterone is used for diagnosis.