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Gonads are the ovaries and testes The function is to form eggs and sperm Other reproductive structures carry the sex cells to where they can meet and unite Sexual maturation, formation of sex cells, and pregnancy are tightly controlled by hormones

17.1 Male Reproductive System Primary functions Production of male hormones Formation of sperm cells Placement of sperm cells in the female reproductive tract

Organs of the male reproductive system Paired testes Ducts to store and transport sperm Accessory glands External accessory structures

Testis Protected by a capsule of fibrous connective tissue Also serves to divide testis into lobules Each lobule holds several seminiferous tubules

Seminiferous tubules Produces Sperm (Spermatogenesis)

Supporting (sustantacular) cells Interstitial cells Support and nourish spermatogenic cells Interstitial cells Fills spaces between seminiferous tubules Produce male sex hormones (testosterone)

Accessory Ducts Carry sperm from testes to outside of the body Various types of ducts Epididymus Vas deferens Ejaculatory duct Urethra

Epididymis Vas Deferens Receives sperm from seminiferous tubules Site of sperm maturation Vas Deferens Extends from epididymus, through inguinal canal, enters pelvic cavity,runs along lateral surface of bladder Uses peristalsis to move sperm

Ejaculatory Duct Urethra Forms by union of vas deferens and duct from seminal vesicles under the bladder Passes through prostate gland and enters the urethra Contracts to push sperm and fluids into urethra Urethra Extends from the urinary bladder to the end of the penis Two roles Transport urine Carries semen during ejaculation Cannot do both functions simultaneously

Accessory Glands Three different glands make secretions involved in the reproductive process Seminal vesicles Prostate gland Bulbourethral glands

Seminal Vesicles Paired glands whose duct merges with the vas deferens Secrete an alkaline fluid Help regulate pH of semen Secrete fructose Serves as energy source for sperm cells

Prostate Gland Doughnut-shaped gland encircling the urethra Secretes into the urethra a milky fluid Keeps sperm pH slightly alkaline Activates swimming movements of sperm

Bulbourethral Glands Located near the base of the penis In response to sexual stimulation, it secretes an alkaline, mucus like fluid into urethra Neutralizes acidity of urethra Lubricates the end of the penis

Semen Fluid that passes from urethra during ejaculation Composition Sperm and secretions from all three glands Slightly alkaline Contains nutrients for sperm cells Has molecules to activate sperm motility Volume of ejaculate is 3-6ml with ~50 to 150 million sperms per ml

Scrotum External sac of skin that holds the testes Testes migrate into the scrotum during 7th month of development Controlled by testosterone Contains muscle fibers Raise and lower the scrotum and testes Adjusts temperature of the testes Normal temperature is 3° degrees lower than body temperature

Penis Copulatory organ that deposits sperm into female vagina Composed of spongy erectile tissue Corpora cavernosa: 2 columns located dorsally Corpus spongiosum: located ventrally Glans penis: tip of the penis Prepuce: foreskin

17.4 Female Reproductive System Functions Produces female sex hormones Produces female sex cells (eggs) Transports eggs to site where they can meet sperm Provides environment for development of offspring Actively involved in birthing process Supplies offspring with nutrients after birth

Structures Paired ovaries Paired uterine tubes Uterus Vagina Accessory glands External organs

Ovaries Produces eggs (oocytes) and sex hormones Estrogen and progesterone Oogenesis (ova production) Oocytes develop inside follicles and are released (one at a time) monthly during ovulation The empty follicle becomes the corpus luteum. Releases progesterone to prep the body for pregnancy If no pregnancy, corpus luteum becomes the corpus albicans

Uterine Tubes Extends from surface of ovary to the uterus Infundibulum envelops the ovary Possesses fimbriae Inside lining possesses simple ciliated columnar epithelium Draws the secondary oocyte into the infundibulum and towards the uterus

Uterus Posterior to bladder in pelvic cavity Superior to the vagina and bent anteriorly over the bladder Hollow organ with thick muscular walls Provides an appropriate internal environment for a growing baby

Possesses two regions Cervix Body Inserts into vagina Upper portion attached to uterine tubes

Uterine wall possesses three layers Endometrium Lines interior Sheds during menstruation Myometrium Smooth muscle Perimetrium Covers the exterior surface

Vagina Collapsible tube extending from uterus to the outside Posterior to urethra and anterior to rectum Functions Copulatory organ Birth canal

External Accessory Structures Vulva Surrounds the urethral and vaginal openings Labia majora Paired folds of hair covered skin covering adipose and muscle Join anteriorly at the mons pubis Formed from same embryonic tissue as scrotum

Labia minora Vestibule Paired, thinner, longitudinal folds medial to labia majora Join anteriorly to form a covering over the clitoris Vestibule Narrow space between the labia minora Possess openings for urethra and vagina Vestibular glands, lateral to vagina, secrete into this space

Clitoris Nodule of erectile tissue at anterior union of labia minora Corresponds to penis in males Abundant in sensory endings leading to female sexual response