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 principle sex hormone responsible for the development of reproductive function in male vertebrates. Testosterone is one of the hormones referred to as androgens, which are also known of as anabolic steroids.As a steroid hormone, testosterone is derived from cholesterol and the structure of this hormone is similar across all mammals, reptiles, birds and fish.unction. In males, testosterone is required for the development of male sex organs such as increased penis and testes size. The hormone also promotes the development of sexual male characteristics during puberty such as voice deepening and the growth of armpit, chest and pubic hair.