Male Reproductive System Testes Primary reproductive organs Male

Male Reproductive System

Testes Primary reproductive organs Male gonads

Structures of the Testes � Tunica Albuginea › Fibrous connective tissue surrounding testes � Septa-divisions › Seminiferoud Tubules: Spermforming factories � Interstitial Cells › Produces testosterone

Duct System � Epididymis › Highly coiled tube › First part of the male duct system › Temporary storage site for immature sperm that enter it from the testes › Sperm mature along the trip (20 days) › Walls contract to expel sperm � Ductus Deferens (carrying away) or Vas Deferens › Runs upward from the epididymis › Empties into the ejaculatory duct › Main Function: �Propel live sperm from their storage sites into urethra Vasectomy �Cuts or cauterizes the vas deferens

Urethra: Three named regions › Prostatic Urethra �Surrounded by the prostate gland › Membranous Urethra �Spanning the distance from prostatic urethra to penis › Spongy (penile) Urethra �Running the length of the penis › Male urethra carries both urine and sperm › Bladder sphincter constricts �prevents passage of urine �Also prevents sperm from entering bladder

3 Accessory Glands & Semen › Produce the bulk of semen › Semen is sperm containing fluid 1. Seminal Vesicles › Located at the base of the bladder › Produce 60% of the fluid volume of semen › Thick, yellowish liquid �Rich in Fructose �Vitamin C � Nourishes and activates the sperm

Accessory Glands continued 2. Prostate Gland – size of a chestnut › Secretes a milky fluid that plays a role in activating, nourishes & protects sperm 3. Bulbourethral Glands – pea sized › Produces a thick clear mucus that drains into the penile urethra › This is the first to pass down the urethra › Cleanses the urethra of traces of acidic urine › Lubricant during sexual intercourse

Semen › Milky white, somewhat sticky mixture of sperm and accessory gland secretions › Contains chemicals that protect the sperm and aid in their movement › About 2 -5 ml and between 50 -130 million sperm in each milliliter �

External Genitalia �Scrotum › Divided sac of skin that hangs outside the abdominal cavity, between the legs and at the root of the penis › Provides testes with temperature below body temperature › Viable sperm cannot be produced at body temperature

� Penis › Designed to deliver sperm into female reproductive tract � Shaft › Ends in an enlarged tip (Glans Penis) › Skin covering is loose and folds downward to form a cuff of skin (prepuce) or foreskin › Inside are three elongated areas of erectile tissue � Spongy tissue that fills with blood and becomes rigid (erection)

Sperm Anatomy

Male Reproductive Functions � Chief Role › Produce sperm and the hormone testosterone � Spermatogenesis – sperm production › Begins at puberty › Everyday a man makes millions of sperm Spermiogenesis �Last stage of sperm development �Compacted into head, midpiece and tail �Sperm head �Contains DNA �Acrosome – anterior to nucleus �Breaks down & releases enzymes that help the sperm penetrate through the follicle cells that surround the egg.