Male Reproductive System

(functions)

-synthesizes sperm (the male gametes)

-stores the sperm

-delivers sperm to the female tract

-testes descend to the scrotum where the cooler temperature permits sperm formation

-testis drags its duct, vessels, and nerves along (the spermatic cord)

-vessels and nerves for the testis and the vas deferens are bundled together

-pass through the abdominal wall in the inguinal canal

-an organ that is out of place

-most commonly a loop of the small intestine descends through the weak area

Testis

(structure)

-surrounded by the tunica albuginea 

-septa are extensions of the capsule that  divide and support the testis

-seminiferous tubules are coiled among the septa

-the acrosome form: contains enzymes for fertilization

-the flagellum forms: allows the sperm to swim

-all excess cytoplasm and organelles are sloughed

Spermiogenesis

(sperm anatomy)

-head: contains DNA and the acrosome

-midpiece: contains many mitochondria

-tail: is the flagellum

-sperm are produced constantly- not "on demand"

-400 million sperm are produced each day

-40-100 million are released during one ejaculation

-within the seminiferous tubules

-deliver nutrients to the spermatogenic cells

-spermatogenic cells nestle into the Sertoli cells as they move toward the lumen

-respond to FSH

-secrete ABP: androden binding protein

-form the blood-testis barrier

-endocrine cells of the testis

-stimulated by LH from anterior pituitary gland to secrete testosterone

-stimulates spermatogenesis in the adjacent seminiferous tubules

-stimulates function of the other male reproductive organs

-stimulates secondary sexual characteristics

Testosterone

(secondary effects)

-facial hair

-increased muscle mass

-deeper voice

Epididymis

(function) 

-resorbs shed cytoplasm and damaged sperm

-sperm storage

-site of sperm maturation

-site of swimming lessons

-within the spermatic cord: vessels, nerves, and muscle

Vas Deferens

(function)

-sperm storage

-contracts during sexual response

-cut for vasectomy

-"reversible" male sterilization (not guaranteed)

-Vas deferens are isolated from the spermatic cord

-a section is removed

-one or both of the open ends are cauterized(heat), tied, or clipped

Accessory Glands

(list three)

-seminal vesicles

-prostate gland

-bulbourethral gland

Seminal vesicles

(function)

-add secretions to the sperm during the sexual response (fructose as an energy source for sperm, substances that neutralize the acidity of the vagina)

-duct combines with the vas deferens to form the ejaculatory duct

Prostate gland

(function)

-surrounds the proximal part of the urethra

-adds secretions to the sperm during the sexual response

-multiple ducts drain into prostatic urethra

-secretions include enzymes that liquefy the semen(decrease vacosity of semen=less thick, easier to move)

-most common type of cancer in men

-second leading cause of cancer deaths after lung cancer

Prostate cancer

(screening)

-digital rectal exam (use finger to palpate surface of prostate)

-measure PSA levels (prostate specific antigen)

Bulbourethral gland

(function)

-embedded in the muscle of the urogenital diaphragm

-secrete during sexual response to flush any residual urine from the urethra (first fluid released, washes out urethra before semen is released)

Male urethra

(three types)

-Prostatic urethra: surrounded by prostate gland, receives semen during the sexual response

-Membranous urethra: penetrates the urogenital diaphragm

-Penile/spongy urethra: surrounded by erectile tissue- the corpus spongiosum

-contains three cylinders of erectile tissue: corpora cavernosa and corpus spongiosum

-these are networks of blood vessels surrounded by dense CT- the tunica albuginea

-vessels dilate during sexual response to cause erection