External structure of the
• glans penis
• prepuce (foreskin)
Testis are the male gonads.
• seminiferous tubules- form sperm
• Leydig cells (interstitial cells)- produce
androgens (ex. Testosterone, ABP).
Testes are located in the scrotum,
outside the body cavity.
• This keeps testicular temperature cooler
than the body cavity.
• The testes develop in the body cavity and
descend into the scrotum just before birth.
• Seminal fluid is thick, yellowish, and
• It contains mucus, fructose, a coagulating
enzyme, ascorbic acid, and
• Accessory glands:
• A pair of glands that secrete a liquid
component of semen into the vas deferens.
• Secretion is alkaline
• Contains fructose, asorbic acid, coagulating
• Location- surrounds and opens into the urethra where it
leaves the bladder.
• Secretion- slightly alkaline fluid that activates the sperm
and prevents them from sticking together
• Prostate problems are common in males over 40.
• Prostate cancer is one of the most common cancers
Bulbourethral gland (Cowper’s gland):
• Location- paired glands that lie beneath the prostate
• Secretion- a thick, clear alkaline mucous that drains into
the membranous urethra.
• Function- It acts to wash residual urine out of the urethra
when ejaculating semen-- raises pH; neutralizes acidity of
Acts on anterior pituitaryActs on anterior pituitary
Inhibits FSH productionInhibits FSH production
Acts on hypothalamusActs on hypothalamus
Inhibits GnRH productionInhibits GnRH production
Hormonal Control of
Some Other Effects of
muscle and bone growthmuscle and bone growth
facial and pubic hair growthfacial and pubic hair growth
thickening of vocal cordsthickening of vocal cords
growth of pharyngeal cartilagegrowth of pharyngeal cartilage
hair follicle effectshair follicle effects
stimulates sebaceous glandsstimulates sebaceous glands
Increased BMRIncreased BMR
Ovary- contains 400,000 oocytes; release
about 500 in a lifetime
• Ovary- under influence of FSH. The
follicles mature every 28 days
• Primary follicle produces estrogens
• And primary oocyte completes its 1st
division produces 2ndary oocyte and
• Aprox 1/2 way through the 28 day cycle the
follicle reaches the mature Vesticular or
Graffian follicle stage.
• Estrogen levels rise and release LH and FSH
and triggers ovulation.
• The 2ndary oocyte travels down the uterine
tube to the uterus.
• If fertilized by sperm, it will produce a zygote
Ovum in uterine tube
Some Other Effects ofSome Other Effects of
• breast development
• external genitalia growth
• bone growth
• fat deposition
• Increase protein anabolism
• Decrease blood cholesterol
• Facilitate calcium uptake
• Promotes hydration of skin
• Feminizes brain
Menopause: cessation of ovarian and
• Usually occurs between ages 46 and 54.
• Due to ovaries decreased responsiveness
• changes in sexual desire
• triggers mood swings
• causes debilitating hot flashes
• may lead to bone and heart problems
• short-term memory loss