The Reproductive System “The male”

The Function Androgen hormones, mainly testosterone bring about sexual maturity Testosterone induces maturation of sperm and secondary sex characteristics Facial hair Wide jaws Deep voice Adam’s apple

Male Organs Essential Organs Gonads in males are the testes Testes produces sex cells, sperm Accessory Organs Genital Ducts Epididymides(a pair) Vas deferentia(a pair) Ejaculatory ducts(a pair) Urethra

Male Organs Glands Seminal vesicles(a pair) Bulbourethral (Cowper’s) glands(a pair) Prostate

Perineum Made up of the urogenital triangle and anal triangle Muscles found there make up the pelvic floor, they control defecation and urination

The Testes Are cased in the scrotal sac Each testis is surrounded by a fibrous capsule called the tunica albuginea The testes are divided into lobules that are packed full of seminiferous tubules Testicles refers to the testis, scrotum, & spermatic cord The left testicle is usually 1 cm lower than the right

Spermatogenesis Spermatogenesis occurs within the seminiferous tubules

Spermatozoa Sperm are fully formed in the seminiferous tubules Go through a “ripening” process as they pass through the genital ducts Before being able to fertilize an egg they must go through a process called capacitation During capacitation enzymes from the sperm break down cervical mucus to get to the egg

Spermatogenesis

Testosterone Promotes male sexual behavior Testosterone is released by Leydig cells in the seminiferous tubules Promotes male sexual behavior Maintains prostate and seminal vesicles Promotes protein anabolism and bone growth Increases muscle development Erectile function Leads to epiphyseal closure

Testosterone Seminiferous tubule Leydig Cells

Genital Ducts Epididymis Located on top of and behind the testis. Comma-shaped, tightly coiled tubule that continues into the vas deferens The seminiferous tubules empty into the epididymis via the efferent ducts Sperm spend 1 to 3 weeks maturing here

Genital Ducts Vas Deferens (ductus deferens) Thick muscular cord that continues from epididymis Travels up the inguinal canal, behind the bladder where it joins with a seminal vesicle Sperm may stay in here for 1 month without a loss of fertility

Genital Ducts Ejaculatory Duct Two short tubules formed after the vas deferens join the seminal vesicles They join together and pass through the prostate gland terminating in the urethra The urethra is the last genital duct sperm pass through

Reproductive Glands Seminal Vesicles Located posterior to the lower part of the bladder Secrete an alkaline, viscous fluid that makes up 60% of semen Alkalinity helps to neutralize acidity of the vagina Fluid contains fructose to nourish sperm

Reproductive Glands Prostate Gland Donut-shaped gland located directly below the bladder and surrounding the urethra Secretes milky, slightly acidic fluid that makes up 30% of semen Contains citrate to nourish sperm and enzymes to activate sperm

Reproductive Glands Bulbourethral (Cowper’s) Glands Two pea-shaped glands located at the top of the penile portion of the urethra Secrete alkaline fluid and lubricating fluid

Supporting Structures Scrotum Divided by a septum, each halve housing a testis, epididymis and spermatic cord It has special muscles that contract and relax to move the testes closer to or farther away from the body This action ensures optimum temperature for sperm formation (3 degrees lower than body temp)

Supporting Structures Penis Composed of three masses of erectile tissue held together by skin Two upper larger cylinders are the corpora cavernosa, (engorges with blood) The lower one houses the urethra and is called the corpus spongiosum The most distal region is called the glans and is surrounded by the foreskin (prepuce) Penis allows for sexual intercourse and delivery of sperm

Disorders Inguinal hernia- when intestines push through wall of abdominal cavity causing swelling in scrotum Hypospadias- opening of urethra is located in ventral side of the penis Epispadias- opening of urethra is located on dorsal side of penis Infertility- low ability to reproduce Sterility- complete inability to reproduce Cryptorchidism- testes are “hidden” in abdominal cavity in infant Prostatic hypertrophy- occurs in 75% of men over the age of 50