Chp 13 The Reproductive Systems Flashcards
scrotum
contains male gonads (testes)
Functions:
-temperature regulation - sperm synthesis must occur at a few degrees below normal body temp
testes functions
spermatogenesis - synthesis of sperm
secretion of male sex hormones (androgens)
sites of spermatogensis
seminiferous tubules
sustentacular cells
known as sertoli cells
-protect and nurture developing sperm physically and chemically
interstitial cells
aka leydig cells
responsibly for androgen synthesis
seminal vesicles
located posterior surface of the bladder
secrete semen into the ejaculatory duct
glands that produce semen
(3)
seminal vesicles 60%
prostrate 35 % - mlidly alkaline
bulbourethral glands 5% - highly alkaline (neutralize leftover urine and lubricate urethra)
collectively referred to as the accessory glands
arousal
dependent on parasympathetic nervous input
subdivided into two stages:
- erection
-lubrication
erection
male: dilation of arteries supplying erectile tissue
female: clitoris and labia minora swell with blood
lubrication
function of parasympathetic system
male: viscous fluid released by bulbourethral gland
female: greater vistubular glands and vaginal epithelium secrete mucus
orgasm
requires stimulation by sympathetic nervous system
divided into two stages
- emission
-ejaculation
emission
male: propulsion of sperm (from ductus deferens) and semen (from accessory glands) into the urethra by smooth muscle contraction
ejaculation
male: semen is propelled out of the urethra by rhythmic contractions of muscles surrounding the base of the penis
female: n/a
resolution
return to normal unstimulated state controlled by sympathetic nervous system
- 2 -3 minutes for males
- 20 - 30 minutes for females
hormones involved in spermatogensis
- testosterone - stimulates division of spermatogonia
- luteinizing hormone (LH) - stimulates interstitial cells to secrete testosterone
- follicle stimulating hormone (FSH) - stimulates sustanacular cells
- inhibin - secreted by sustanacular cells to inhibit FSH
testosterone
stimulates division of spermatogonia
luteinizing hormone (LH)
stimulates interstitial cells to secrete testosterone
follicle stimulating hormone (FSH)
stimulates sustanacular cells
stimulates spermatagonia to increase
inhibin
secreted by sustanacular cells to inhibit FSH
female chromosomes
XX
male chromosomes
XY
wolffian ducts
can develop into male internal genitalia
mullerian ducts
can develop into female internal genitalia
- occurs by default in absence of Y chromosome
regression of mullerian ducts caused by MIF mullerian inhibiting factor
mullerian inhibiting factor (MIF)
produced by the testes and causes regression of mullerian ducts > prevents formation of female internal genetalia
testes and ovaries are considered
homologous organs because they are derived from the same undeveloped structure
androgens
all hormones involved in the development and maintenance of male characteristics
-ex: primary androgen = testosterone
estrogens
all hormones involved in the development and maintenance of female characteristics
- ex: primary estrogen = estradiol
male secondary characteristcs
maturation of genitalia
male distribution of facial and body hair
deepening of voice
increased muscle mass
female secondary characteristics
maturation of genitalia
breast development
wider hips
pubic hair