Male Reproduction Flashcards
sexual reproduction (3)
- offspring has 2 parents and receives genetic material from both
- genetic diversity
- foundation for survival and evolution
primary sex organs
produce gametes
secondary sex characteristics
develop at puberty
week 5-6 (3)
- develop of fetus is sexually undifferentiated
- contains 2 ducts
- undeveloped gonads
what are the 2 ducts?
- Wolffian duct (mesonephric)
- Mullerian duct (parasympathetic)
wolffian duct system
-develops in male; degenerates in female
mullerian duct system
-develop in female; degenerates in male
chromatids are ________; chromosomes code for the same ____
identical; trait
what controls development or degeneration of a duct system?
Y chromosome contains the sex determining region (SRY)
SRY gene
codes for transcription factor (testis-determining factor)
testis determining factor activates
-androgen receptors-> stimulates wolffian duct system
also mullerian inhibiting factor
the mullerian inhibiting factor
-blocks the production of aromatase
aromatase
Testosterone converted to estradiol
week 8
the correct duct system is developed, but the external organs do not match
what does the external genitalia contain (3)
- phallus or genital tubule
- 2 urogential folds
- 2 labioscrotal folds
phallus or gential tubule//male? female?
male->penis formation
female->clitoris
urogenital folds// male? female?
male->urethra
female->labia minor and hymen
labioscrotal folds//male? female?
male->scrotum
female->labia majora
week 9
begin to show sexual differentiation
week 12
distinctly male or female
androgen insensitivity syndrome (2)
- genetically male
- testosterone secreted, but the androgen receptors are absent
scrotum
regulates temperature of the testis
testes begin their development near the _____. and begins in weeks _____
kidney; 6-10
gubernaculum (2)
- extends from gonad to abdominopelvic scrotum
- guides testes to scrotum
cremaster muscle
pulls testes close to body
dartos muscle
wrinkles skin reducing surface area of scrotum
what is responsible for the countercurrent heat exchange needed by the testes?
pampiniform plexus
pampiniform plexus (3)
- countercurrent heat exchanger cooles arterial blood entering testis
- low flow rate
- low O2 levels
___ divides testes into compartments containing the seminiferous tubules
septa
seminferous tubules
site of sperm production
lineage of sperm production (5)
spermatogonia->primary spermatocyte-> secondary spermatocyte->spermatids->sperm
sertoli cells (3)
- blood testes barrier
- produce androgen binding protein
- nurse cell
leydig cells (2)
- between seminiferous tubules
- produce androgen
cells that produce androgen (2)
- serotoli
- leydig
route sperm uses to exit the penis? (7)
seminiferous tubules->rete testis->efferent ductule->epididymis->vas deferens->ejaculartory duct->urethra
epididymis
site of sperm maturation and storage
accessory glands of the male reproductive system (3)
- seminal vesicle
- bulbourethral gland
- prostate gland
seminal vesicle (3)
- viscous yellow fluid
- last fluid added to semen
- 60% volume of semen
prostate gland (2)
- thin milky fluid
- 30% volume of semen
bulbourethral gland
produces alkaline (basic) secretion before ejaculation
semen is mostly composed of ?
- seminal vesicle fluid (60%)
- sperm (10%)
- prostatic fluid (30%)
other components of sperm (5)
- calcium phosphate ions
- fructose and citrate
- seminogelin
- serine protease
- prostaglandins
what allows the penis to erect? (2)
- corpus sponginosum
- corpus carvernosa
viagra blocks the enzyme _____ which break down ____
phosphodiesterases (PDE5); cGMP
male sexual response (4)
excitment->orgasm->resolution->refractory period
erection:
when ___, the arterial branches feeding the erectile tissues are ____, which constrict blood flow
flaccid; constricted
erection:
during sexual arousal ____ nerves trigger the release of ___ ___ which stimulates the production of cGMP in smooth muscle
parasympathetic; nitric oxide
erection:
cGMP triggers the relaxation of ______ in the arteries and send blood to the erectile tissue
smooth muscle
erection:
what helps the penis maintain erection
filled veins from the tissues
excitement:_______:orgasm:_____
parasympathetic; sympathetic
orgasm contains 2 components what are they?
- emission
- expulsion
emission (3)
- peristalic contractions of smooth muscle
- pushes sperm into the prostatic urethra
- squeezes fluid seminal vesicles and prostate
expolusion
- powerful rhythmic contractions of ischocavernosa and bulbospongious muscles
- pleasureable sensation (eleveated oxytocin)
ischocavernosus
stiffens the penis
bulbospongious
pushes the semen out of the urethra
resolution (2)
- blood flow to the penis slows
- follows after ejaculation
refractory period
period when you can attain second erection
mitosis produces
2 genetically identical daughter cell
meiosis produces
gametes
that is the importance of meiosis (2)
- reduce the chromosomal number in half
- introduces genetic variation
____ only undergoes mitosis
spermatogonium
sperm formation (2)
- takes 74 days
- begins around age 14
spermatogenesis (2)
- sperm formation
- occurs in the seminiferous tubules
spermiogenesis (2)
- spermatids->sperm
- is a mobile cell with 4 components
what are the 2 daughter cells produced from the spermatogonia?
type A:replacement for the spermatogonia via mitosis
type B: primary spermatocyte
Type B->
How many chromosomes?
- spermatocyte
- forms the secondary spermatocyte (23 chromosomes)
Secondary spermatocyte->
How many chromatids?
4 spermatids; 23 chromatids
all sperm undergoes ______
spermiogenesis
what are the 4 components of sperm?
- head (acrosomal cap;contains 23 chromatids)
- neck (contain centrioles)
- midpiece (contain mitochondria)
- tail (flagella)
testosterone during puberty?adulthood?
puberty: enlargement of secondary organs, stimulates erythropoiesis
adulthood: stimulates libido and spermatogenesis
gnRH (2)
- gonadotropin releasing hormone stimulates anterior pituitary to release FSH and LH
- starts puberty
FSH
follicle stimulating hormone
-stimulates sertoli cells to produce androgen binding protein
LH
luteinizing hormone
-stimulate Leydig cells to produce testosterone
testosterone inhibits?
gnRH release
