9.1 - Male and Female Reproductive Tracts Flashcards
Function of External Genitalia
- protect internal genital organs
- provide pleasure
- allow sperm to enter body
External Sex Organs
1) Vulva
2) Mons Pubis
- fatty tissue that covers pubis bone
- sebaceous glands secrete pheromones
3) Labia majora - fleshy folds
- contain glands that produce lubricating secretions
- protect external genital organs
4) Labia minora - inside labia majora
- becomes engorged during sex
- highly vasculated
5) Urethra Orifus
- urethral opening (in front + above vagina opening)
6) Clitoris
- sensitive to sexual stimulation
7) Vaginal opening
8) Perineum - area bw vagina and anus
8) Vestibular apparatus
- secretes lubricant during sex
Internal Sex Organs
1) Vagina
- passageway for sperm to enter, menstrual blood to exit, and childbirth
- vaginal lining produce secretions to maintain moisture and pH
- surrounded by elastic tissue; enables stretching during birth
2) Uterus
- supports and nourishes fetus during pregnancy
- thick-walled
a. cervix: lower part of uterus
b. cervical os: opening of uterus
- allows sperm to enter and blood to exit
- protective barriers (guards uterine cavity from pathogens)
c. cervical lining
- produces mucous (barrier to sperm)
- during ovulation, mucous becomes thin and clear to increase risk of fertilization
3) Uterine/Fallopian tubes
4) Ovaries
Structures of the Uterus
1) Corpus - elastic
- allows fetus to grow
- fundus: upper part of uterus
- contracts to prevent haemorrhage
after birth
2) Uterine wall - 3 layers
- endometrium - inner layer
- if fertilization does not occur, this sheds as blood
- if fertilization occurs, it supports attachment of placenta - myometrium - middle layer
- contains smooth muscle (contracts during birth) ‘ - perimetrium - outer
- provides structural support
Uterine/Fallopian Tubes
- paired tube structures (extend toward each ovary)
- inner layer: mucosal layer and cilia that helps transport oocyte to uterus
- uterine wall contains smooth muscle to help push oocyte into uterus
- ampulla: where fertilization occurs
Infundibulum
- funnel structure at end of tube
- has fimbriae (that capture oocyte)
Ovaries
- connected to each side of uterus
- produce estrogen and progesterone
- site of oogenesis: where immature oocytes produce and mature
Follicles
- contains oocyte and releases them during ovulation
- follicle development occurs cyclically with hormone signalling
Human Eggs
- females are born with all of the oocytes they will have in their lifetime
Atresia: natural process of cell-degeneration where oocytes degenerate before birth
- only small amount of oocytes (400) mature and release during ovulation
- they freeze in meoisis I which makes them vulnerable to mutations
Menstruation Cycle
Menarche
- 1st period
- indicates puberty onset
Menopause
- end of reproductive years
- oocytes can no longer response to maturation signals
Hormone Regulation
- hypothalamus releases gonadotropin-releases hormone
- GnRH promote anterior pituitary gland to secrete LH and FSH
- LH and FSH stimulate ovaries to produce estrogen and progesterone
Female Cycles
1) Menstruation
- day 1
- decline progesterone and estrogen
- corpus luteum degenerates
- endometrium sheds
- blood contains fibrinolysis to prevent clotting
2) Follicular (proliferative)
- day 6
- estrogen promotes regeneration/thickening of endometrial lining
- ↑ FSH = develops follicles
3) Ovulation
- day 14
- high estrogen = LH surge
- oocytes are released and captured by fimbriae
4) Luteal (secretory)
- rupture follicle become corpus luteum
- endometrium thickens
- NO fertilization = corpus luteum degenerates = ↓ progesterone and estrogen
- fertilization = embryo releases human chorionic gonadotropin which maintains corpus luteum and high progestersone
Hormonal Regulation of Menstrual and Ovarian Cycles
1) Hypothalamus release GnRH which stimulates the anterior pituitary to release FSH andLH
2) FSH stimulates follicle development and produce estrogen
3) High estrogen causes a surge in LH
- LH is needed for oocyte maturation
4) 1 Follicle reaches full maturation and gets release during ovulation
- remaining follicles undergo atresia
Ovarian Follicular Changes
During Ovulation
- mature graafian (mature) follicle presses on ovarian surface = rupture = releases 2ndary oocyte
- surge of LH weakens ovarian wall (triggers enzymes that break it down)
After Ovulation
- remainders of ruptured follicle become the corpus luteum (leutinization)
- cells in follicle (granulosa and thesa) undergo changes
granulosa: granulosa lutein
thesa: thesa lutein
- these cells produce estrogen and progesterone which suppresses GnRH and thus reduces release of LH and FSH
AFTER release of 2ndary oocyte
- oocyte is captured by fimbriae and enters ampulla
IF fertilization occurs:
- corpus luteum produces progesterone and estrogen
Fertilization does NOT happen:
- corpus luteum degenerates into corpus albicans
- progesterone ad estrogen levels drop (thats what maintains uterine lining)
Male External Reproductive Structures
1) Penis
- root: anchored to the body and provides stability
- Shaft: channel for urinary and reproductive tracts
- Glans Penis: tip containing urethral orifus
- Corona: rim around glands
- Foreskin: covers glands
2) Scrotum
- skin and muscular tissue that encloses the testes
- provides optimal temp regulation for sperm
- Dartus muscle: retains heat
- Cremastur muscle: surrounds spermatic cord (brings tests close to body for warmth or further for cooling)
Erectile Tissue
1) Vascular Sinoids
- engorge with blood (mediated by PSNS) and cause an erection
2) Corpora Cavernosa
- provide rigidity during erection
- paired structure on back side
3) Corpus Spongiosom
- prevents urethra from compression during erection
- ventral (side)
Testes
- in the scrotum
Spermatogenesis: production of sperm in seminiferous tubules
- Sertoli cells: support and nourish developing sperm
- Leydig: produce testosterone
Seminiferous Tubules
- where spermatogenesis occurs
Sertoli Cells
- provide support and nourishment for developing sperm cells
- release signals for sperm development
- form blood barrier in testes
Leydig Cells
- produced testosterone (androgen that stimulates sperm production)
