REPRODUCTION Flashcards
external male genitalia
Penis
scrotum
internal male genitalia
seminal vesicle
ejaculatory duct
epididymis
vas deferens
prostate gland
bulbourethral gland
male gonads
§ Primary reproductive organs to produce gametes (sperms) and secrete sex hormones (testosterones)
§ Testis:
□ pair, located in scrotum, skin-covered sac suspended
□ Produce sperm, testosterone
male testes descent
1) Testosterone release from fetal testes
2) Shorten gubernaculum (cord of muscle)
3) Decent completed usually by 7th mnth of gestation
a) Testes descent (rear of abdominal cavity)
4) descent on 2 sides of scrotum
why testes needs to descent
• Spermatogenesis
• Temperature sensitive
• Cannot occur at normal body temp
• 35*C (<2)
(Temperature to produce viable sperms)
undescended testes
Undescended testes into adulthood (cryptorchidism)
• Rare
• Surgical intervention
temperature in scrotum
35
when does spermatogenesis occurs?
PUBERTY
• Enlargement of testes and development of 2nd characteristics
• Hormonal changes “raging hormones”
spermatogenesis HORMONES, cells and duration
inhibin (from sertoli cell)
- nutrients for sperm prod, support
Testosterone (Leydig cell)
germ cells at various stage of differentiation, each take 64 days, does not occur synchrously
hormones in puberty (male)
Testosterone (Leydig cell)
GnRH (Gonadotropic-releasing hormone) (hypo)
LH (luteinizing hormone) – (ant pitui)
FSH (follicle stimulating hormone) – (ant pitui)
Inhibin (from sertoli cell)
- nutrients for sperm prod
why is GnRH released in pulsatile ~1-3hrs
hypothalamus release GnRH
for proper functioning of testes, regulate secretion of FSH, LH (also in pulsatile)
if constant GnRH exposure to gonadotrophs, desensitised GnRH receptors (overall decr LH, FSH)
control of testicular function byNEGATIVE FEEDBACK:
1) testosterone incr
2) act on hypothalamus, anterior pituitary
3) decr GnRH release by acting on hypothalamus
4) indirectly decr LH, FSH release by (ant, pitui)
2) act on sertoli cell, incr inhibin production
3) inhibit FSH secretion
effects of testosterone
• Internal male genitals (differentiation)
• Pubertal growth spurt
• Penis (growth)
• Deepening of voice
• Spermatogenesis
• Libido
• Muscle mass
ANABOLIC STEROIDS EFFECT
- incr in testosteron
- inhibin produced (sertoli cell) to inhibit ant pituitary
- testes do not receive stimulus from ant. pitui (GnRH –> LH, FSH –> testes –> testosterone)
- testosterone secretion, sperm production decr = SHRINK
biosynthesis of DHT
5a-reductase]
Cholesterol precursor —> Dihydrotestosterone [5a-reductase]
+ Estradiol [Aromatase]
effects of DHT
® External male genitalia (differentiation)
® Sebaceous glands
® Prostate (growth)
® Male hair pattern BALDNESS
Male hair pattern BALDNESS
◊ Horseshoe-shaped ring of hair around back of head
◊ Genetic factors –> Androgen receptor gene –> DHT
◊ DHT = body/ facial hair growth promoter that adversely affect prostate/ hair on head
——> Shrinks hair follicles, fewer visible hair left on scalp
——> Therapeutic (DHT inhibitors): block conversion of testosterone –> DHT
Internal female genitalia
§ Cervix
□ Lower part of uterus that opens into vagina
§ Uterus
□ Hollow chamber which embryo develops
§ Vagina (upper 1/3)
□ Organ of sexual intercourse
□ Produce lubricating fluids
□ Birth canal
Uterine duct
Internal female genitalia
§ Cervix
□ Lower part of uterus, opens into vagina
§ Uterus
□ Hollow chamber which embryo develops
§ Vagina (upper 1/3)
□ Organ of sexual intercourse
□ Produce lubricating fluids
□ Birth canal
§ Uterine duct
External genitalia female
§ Clitoris
□ Sexual arousal
§ Labium minus, majus
§ Vagina (lower 2/3)
gonad female
ovary
Site of storage and development of oocytes
key features of ovaries
1) Release eggs, to be fertilised by sperm
2) Produce and secrete female sex hormones
3) Provide environment for fertilised egg to develop during preg
4) Facilitate labor and childbirth
ovary — hormones —> uterus
ovarian cycle affects uterus cycle
importance??
• Ovum producing reproductive organ
• Analogous to testes (M)
Gonads + endocrine gland
• Uterus to maintenance fetus during development
• Expel fetus for preg
• Major hormone responsive reproductive organ
ovarian cycle length, phases
28 days
follicular (mature follicle) –> luteal (corpus luteum)
when is ovarian cycle interrupted
pregnanacy
terminates at menopause
ovaries 2 funciton
1) produce ova, oogenesis
2) secrete sex hormones (estrogen, progesterone) promote fertilisation of ovum, prepare female reproductive tract from preg
estrogen function
1) aids follicle growth, maturation
2) induce antrum formation, estrogen storage site
rise in estrogen
1) hypo – inhibit GnRH (less FSH, LH)
2) pituitary – less FSH
LH rise slowly
LH function
1) differentiation of follicular cells into LUTEAL cells
2) ovulaiton, release mature egg
CL secretes
progesterone
estrogen
progesteron function
1) support ovum if fertilisation occurs
2) inhibit LH, FSH, (no new follicular maturation, ovulation)
uterine cycle duration and phases
28 days
menstrual –> profillerative –> secretory phase
puberty females triggered by
GnRH
rise at puberty, affected by environment, growht hormones in food
signs of puberty in females
• Thelarche (breast)
• Pubarche (axillary, pubic ahir)
• Menarche (1st period)
• Growth 2nd sex organs
• Fat deposition
Rapid incr height (growth hormone)
uterine cycle reflects
• REFLECTS cyclic change of female sex hormones during ovarian cycle
• Prepares female repro tract for fertilisation and implantation of ovum
○ Starts at puberty
•Ends at menopause
menopause cause
Decrease in hormone secretion at midlife (males too)
Cessation of menstruation
menopause treatment/ tamper
- hormone replacement therapy, slow tamper off estrogen
- reduce neg feedback in body which causes rollercoaster in hormone levels
when menopause
• Age 45-55
• Ovaries have fewer remaining follicles
• Less responsive to FSH, LH (gonadotropins)
• Secrete less estrogen, progesterone (CL)
whats happens physically from menopause
• Cessation of menstrual cycle
• 12mnths after last menstrual period
Gradual atrophy genital organs
symptoms of memopause
• Vasomotor changes
• Regulation of blood vessels dilation/ constriction
• Hot flushes!!!
• Skin change
• Psychological, emotional
• Incr cholesterol
• CVS
• Incr osteoporosis risk
• Less E, less bone mass
temp rise during menstruation
0.5*C
