Module 6 - Male Reproductive System Flashcards
Testes anatomy (3)
1) Male gonads
2) Paired
3) Suspended within fascia of the scrotum
Testes function (3)
1) Function of sperm and testosterone production
2) Testosterone
a) Hormone produced by interstitial cells inside connective tissue of testes
3) Each testis has hundreds of lobules, each lobule contains several seminiferous tubules
a) Site of sperm production
Duct system (3)
1) Epididymis (place for sperm to mature)
2) Vas deferens (sperm travel through here)
3) Urethra
Epididymis (3)
1) Attached directly to the testes
2) Sperm travel from seminiferous tubules to epididymis for maturation
3) Maturation takes about 20 days
a) Sperm gain the ability to swim
Vas deferens (3)
1) Mature sperm are propelled into the vas deferens by muscular contractions
2) Contained in the spermatic cord, held in place by the spermatic fascia
a) Surrounds the vas deferens, nerves and blood vessels
3) Travels superiorly through the inguinal canal
Vasectomy (3)
1) Vas deferens is cut and tied off
2) Permanently prevents sperm from exiting the body to fertilize an egg
3) Does not affect testosterone production
Ejaculatory duct (2)
1) Vas deferens joins with duct of seminal vesicle to form the ejaculatory duct
2) Connects into the urethra to provide a means for sperm to exit the body
Urethra (3)
1) Travels from the bladder through the penis
2) Carries both sperm and urine
3) Three regions
a) Prostatic
b) Membranous
c) Spongy
Penis (3)
1) Contains spongy, erectile tissue
2) Distensible blood spaces through the shaft
3) Two parts:
a) Shaft (two corpus cavernosum and one corpus spongiosum)
b) Glans penis - houses the opening of the penis
Erection (4)
1) During arousal, nervous system reflexes cause an increase in blood flow through shaft
2) Spaces fill with blood in the erectile tissue
3) Stiffens, increases in size
4) Enables entry into vaginal canal to deposit semen into female reproductive tract
Scrotum (4)
1) Pouch of skin that holds the testes outside the body
a) Held in place by the spermatic fascia
2) Testes must be located outside the body for sperm production
3) Sperm must be kept at a cooler than body temperature
a) Skin responds to environment to maintain constant temperature for sperm production
Sterility (2)
1) Inability to produce gametes
2) Occurs in males if the testes do not descend into the scrotum during fetal development
Semen (2)
1) Thick whitish fluid that contains sperm and accessory gland secretions
2) Contains
a) fructose (for energy)
b) prostaglandins (helps with movement)
c) relaxin (helps with motility)
d) alkaline pH (offsets acidity of urine)
e) antibiotic (kills bacteria that may be in urethra)
Seminal Vesicles (2)
1) Join with the vas deferens to form the ejaculatory duct
2) Secrete a thick, viscous fluid containing nutrients for use by the sperm
a) Fructose
b) Vitamin C
d) Prostaglandins
Prostate gland (3)
1) Just inferior to the bladder
2) Secretes milky, alkaline fluid
a) Increases motility of sperm
3) In older men, prostate gland may become enlarged
a) Makes urination slow or difficult
b) Compresses on the urethra
Bulbourethral glands (2)
1) Secrete alkaline fluid, which is the first secretion to be released during ejaculation
2) Helps neutralize the acidity of urine in the urethra
Spermatogenesis (4)
1) Production of sperm
2) Takes about 64-72 days to complete
3) Begins at the onset of puberty
4) Males continue to produce sperm throughout their lifetime
Spermatagonia
1) Stem cells that go through mitotic (each cell contains 46 chromosomes) divisions beginning at birth until puberty
2) Spermatogonia form sperm in the seminiferous tubules in the testes
Spermatogenesis - steps during puberty
1) During puberty, anterior pituitary gland secretes FSH
2) FSH causes spermatagonia to undergo cell division
a) One cell continues stem cell line
b) Other cell becomes primary spermatocyte which undergoes meiosis (each cell ends with 23 chromosomes)
3) Meiosis produces four gametes with 23 chromosomes each, called SPERMATIDS
a) All viable gametes after maturation
Spermiogenesis (3)
1) Final stage of spermatogenesis
2) Process by which spermatids mature into sperm
3) Surplus cytoplasm is stripped away
a) All become viable gametes after maturation
Head of mature sperm (3)
1) Almost entirely nucleus
2) Contains cell DA
3) Acrosome
a) Contains enzymes to break down membrane of egg cell to allow sperm to penetrate
Midpiece of mature sperm (2)
1) Numerous mitochondria
2) Needed to supply locomotive energy needed to travel through female reproductive tract
Tail of mature sperm (2)
1) Flagellum
2) Used to propel sperm through female reproductive tract
Graphic of sperm
Male hormones (2)
1) Anterior pituitary secretes LH and FSH beginning at puberty
2) FSH/LH begins testosterone production in testes
Testosterone (2)
1) Stimulates growth in males
2) Stimulates secondary sexual characteristics
a) Broad shoulders
b) Enlargement of larynx
c) Increased muscle size
d) Increased bone density
e) Increased hair growth
