Epididymides Tightly coiled tubes Connected to ducts within the testis Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Tightly coiled tubes Connected to ducts within the testis Promote maturation of sperm cells Epithelial cells Nonmotile cilia Sperm cells © Image Source

© The McGraw-Hill Companies, Inc./Al Telser, photographer Ductus Deferentia Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Are muscular tubes About 45 centimeters each Extends from the epididymis to the ejaculatory duct Lumen Epithelium Smooth muscle (a) Sperm in lumen of ductus deferens Pseudostratified colum- nar epithelium Smooth muscle (b) © The McGraw-Hill Companies, Inc./Al Telser, photographer

Seminal Vesicles Attached to the vas deferens near base of the urinary bladder Secrete alkaline fluid Secrete fructose and prostaglandins Contents empty into the ejaculatory duct Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Ureter Urinary bladder Ampulla Seminal vesicle Ejaculatory duct Bulbourethral gland Prostate gland Bulb of penis Root of penis Ductus (vas) deferens Crus of penis Epididymis Testis Penis Urethra Body of penis Glans penis (b)

Manfred Kage/Peter Arnold Prostate Gland Surrounds the proximal portion of the urethra The ducts of the gland open into the urethra Secretes a thin, milky, alkaline fluid Secretion enhances fluid mobility Composed of tubular glands in connective tissue Also contains smooth muscle Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Secretory cells of the prostate gland Smooth muscle Lumen of urethra Manfred Kage/Peter Arnold

Bulbourethral Glands Inferior to the prostate gland Secrete mucus-like fluid Fluid released in response to sexual stimulation Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Ureter Urinary bladder Ampulla Seminal vesicle Ejaculatory duct Bulbourethral gland Prostate gland Bulb of penis Root of penis Ductus (vas) deferens Crus of penis Epididymis Testis Penis Urethra Body of penis Glans penis (b)

Bulbourethral Glands Inferior to the prostate gland Secrete mucus-like fluid Fluid released in response to sexual stimulation Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Ureter Urinary bladder Ampulla Seminal vesicle Ejaculatory duct Bulbourethral gland Prostate gland Bulb of penis Root of penis Ductus (vas) deferens Crus of penis Epididymis Testis Penis Urethra Body of penis Glans penis (b)

Semen The fluid the urethra conveys to the outside during ejaculation is called semen Semen consists of: Sperm cells Secretions of the seminal vesicles, prostate gland, and bulbourethral glands It is slightly alkaline Contains prostaglandins Contains nutrients Volume is 2-5 milliliters of semen per ejaculation Average 120 million sperm cells per milliliter of semen

Scrotum Pouch of skin and subcutaneous tissue Dartos muscle – smooth muscle in subcutaneous tissue; contracts to cause wrinkling of the scrotum Medial septum divides the scrotum into two chambers Each chamber is lined with a serous membrane Each chamber houses a testis and epididymis

Penis Conveys urine and semen Specialized to become erect for insertion into the vagina Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Superficial dorsal vein Deep dorsal vein Dorsal nerve Dorsal artery Deep artery Corpora cavernosa Tunica albuginea Skin Urethra Subcutaneous tissue Corpus spongiosum Connective tissue (fascia) Prepuce External urethral orifice Glans penis (a) (b)

Erection, Orgasm, and Ejaculation The erection: Parasympathetic nerve impulses Blood accumulates in the erectile tissues The orgasm: Culmination of sexual stimulation Accompanied by emission and ejaculation The ejaculation: Emission is the movement of semen into the urethra Ejaculation is the movement of semen out of the urethra This is largely dependent on sympathetic nerve impulses

Male Sex Hormones The male sex hormones are called androgens Interstitial cells in the testes produce most of them, but small amounts are made in the adrenal cortex Testosterone is the most important

Actions of Testosterone Increased growth of body hair Sometimes decreased growth of scalp hair Enlargement of the larynx and thickening of the vocal cords Thickening of the skin Increased muscular growth Thickening and strengthening of the skeletal bones