A + P Reproductive System I Flashcards
sexual reproduction
process in which organisms produce offspring by means of germ cells called gametes
organs of reproduction are grouped as
gonads -produce gametes and secrete hormones gametes -sex cells ducts -transport, receive, and store gametes accessory sex glands -produce materials that support gametes supporting structures -necessary sex organs for intercourse
unique parts about the reproductive system
not very functional until puberty, when hormonal control takes over and activates it
doesn’t just serve the host; used to perpetuate the species
gonads
- male
- female
male
-testes
female
-ovaries
gametes
- male
- female
male
- spermatozoa (sperm cells)
- ova (egg cells)
ducts
- male
- female
male -epididymis -ductus (vas) deferens -urethra female -uterine (fallopian tube)
accessory glands
- male
- female
male -seminal vesicles -prostate gland -bulbourethral glands female -greater vestibular glands
supporting structures
- male
- female
male
-penis
female
-vagina
scrotum
a cutaneous sac that comes from the abdomen and base of the penis
supports both of the testes
scrotum
- division
- sperm
- -temp.
- -temp. regulation
- -cremaster
division
-vertical septum divides it into two sacs, each containing a single testicle
sperm
-reproduction and survival of sperm require a temperature that is 3 C lower than normal core body temperature
-temp regulated by the cremaster muscle
-cremaster muscle elevates them and brings them closer to the pelvic cavity or relaxes, causing the testes to move farther from the pelvic cavity
testes
- visual
- function
paired oval shaped glands (gonads) within the scrotum
function
-produce sperm and male sex hormones
spermatogenesis
the process by which seminiferous tubules inside the testes produce sperm
seminiferious tubule
- length
- number
30-70 cm long
about 500 tubules per testis (95% of testis volume)
sperm
- production rate
- development time
- maturation time
production -300 million per day development -takes about 64-72 days for each sperm to develop maturation -10-14 days in the epididymis
sperm
- function
- genetics
function
-fertilize a secondary oocyte
each gamete, sperm and ovum, carries half the genetic information needed to create a baby
sperm
-life expentancy
once ejaculated, sperm have a life expentancy of about 24-72 hours within the female reproductive tract
sperm
- ejaculation number
- how many reach the uterine tube
300-400 million sperm will be ejaculated
100-200 will reach the uterine tubes, but only one can fertilize the ovum
hormonal control of spermatogenesis and role of testosterone
at puberty much of this will begin
hypothalamus will increase the release of gonadotropin-releasing hormone (GnRH)
testosterone (produced in testes) and dihydrotestosterone (DHT; produced from testosterone)
GnRH
- stimulates
- -releases
stimulates the anterior pituitary gland to release
- luteinizing hormone (LH)
- follicular stimulating hormone (FSH)
LH function
stimulates the testes to secrete the hormone testosterone
FSH
works with testosterone to create sperm
testosterone
-function
develop male reproductive systems, sexual characteristics, behavior, and function
contribute to spermatogenesis
stimulate muscle development
ducts
epididymis
ductus (vas) deferens
ejaculatory ducts
urethra
epididymis
- location
- function
single coiled duct (3-4 m long) outside the testis that serves as a place for sperm to mature, after which they are either expelled or degenerated
ductus (vas) deferens
-function
stores mature sperm and propels them toward the urethra during ejaculation
ejaculatory ducts
- location
- function
union of ducts for seminal vesicles and ductus (vas) deferens
eject sperm into the urethra
urethra
- location
- function
small tube that leads from the floor of the bladder to the external orifice of the glans penis
functions
-acts as a shared duct of the reproductive and urinary systems, serving as a passageway for semen and urine
urogenital diaphragm (or sphincter) function
closes off during ejaculation that prevents urine from passing into the urethra
accessory sex glands
- function
- structures
function -designed to help sperm survive and more structures -seminal vesicles -prostate -bulbourethral (Cowper's) glands
seminal vesicles
-function
secrete an alkaline, viscous fluid that contains fructose, protsaglandins, and clotting proteins
purpose of fluid in seminal vesicles
alkaline nature of fluid helps to neutralize acid in the male urethra and female reproductive tract
fructose is the ATP production by sperm - food for sperm
prostaglandins contribute to sperm motility and viability
proteins cause coagulation of semen after ejaculation
prostate purpose
secretes a milky, slightly acidic fluid that helps semen with ATP production, and helps semen coagulate and then break down