Unit 3 - Chapter 24 Stucture / fx of reproductive system Flashcards
Differentiation of female and male genitalia
- starts at 7-8 weeks of embryonic development
- gonads of males at this point secrete
1) testosterone
2) TDF or expression of testes-determining factor (male sex determination)
3) SRY gene expression (cascade of steps to form testes)
- until that moment; both male and female are homologous
HPG or hypothalamic-pituitary-gonadal axis
control structure/fx of male and female reproductive systems
* neurologic and hormonal interactions that accelerate puberty and l/t sex maturation and reach reproductive capability
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Paracine hormones (inhibin, activin, and follistatin)
1) inhibin (protein secreted by the Sertoli cells (tubules of testis) in men and by the granulosa cells in women. It inhibits the synthesis and release of the follicle-stimulating hormone in the pituitary gland (perhaps by limiting GnRH) // stimulated from FSH activation
* Inhibin A (luteal phase => further suppresses FSH) including interfering w/ GnRH receptors, restricting prolactin + growth hormone release + promotes break down of intracellular gonadotropins
2) activin - stimulates secretion of FSH and increases pituitary response to GnRH and increases FSH binding in dominant granulosa cells (ovary cells that produce hormones including estrogen and progesterone) // regulate LH stimulation of androgen synthesis (for ovian estrogen biosynthesis)
3) follistatin - inhibits activin and boosts inhibin activity
Extrahypothalamic factors
- (outside the hypothalamus) factors cause hypothalamus to release
1) GnRH, which stimulates anterior pituitary to secrete gonadotropins:
follicle stimulating hormone
a. females
* gonadotropins
* promotes ovarian follicle development (releases egg from ovary)
* stimulate estrogen secretion
b. males
* gonadtropins
* promotes testes development
* promotes sepermatogenesis by sertoli cells
Luteinizing hormone (LH)
a. females
* gonadotropin
* triggers ovulation
* promotes development of corpus luteum (produce progesterone [promotes secretory changes in endometrium during luteal phase, second phase of menstrual cycle @ day 15 of 28 cycle + ends when you get your period, quiets uterine myometrium (muscle) activity and prevents lactogenesis during pregnancy] located on end of ovaries
b. male
* gondatropin
* simulate testerone produciton by Leydig cells of testis
Testerone for both genders:
female
* Libido, learning, sleep, protein anabolism, growth of muscle and bone; growth of pubic and axillary hair; activation of sebaceous glands, accounting for some cases of acne during puberty
male
* Stimulates spermatogenesis, stimulates development of primary and secondary sexual characteristics, promotes growth of muscle and bone (anabolic effect); growth of pubic and axillary hair; activates sebaceous glands, accounting for some cases of acne during puberty; maintains libido
Ova
- primitive female gametes (ova) occur soley during fetal life
- from puberty to menopause - one female gamete matures per menstrual cycle [females release a mature ova at time of puberty]
for males
* sperm begins at puberty
Female reproductive system
1) produce mature ova and, when fertilized, to protect and nourish them through embryonic and fetal life, expel! lol
External female genitalia
1) mon pubis (rounded mass of fatty tissue over pubic symphysis, or pubic mound)
2) labia majora (top, outer fold of skin)
3) labia minora (inner folds of skin that surround opening of vagina and urethra)
4) clitoris (sexual pleasure, sits above urethral orifice at top)
5) vestibule (urinary and vaginal openings)
6) Bartholin gland - pea-sized glands found right behind either side of lips that surround entrance of vagina - secrete fluid that act as lubricant during sex
7) skene’s glands (lesser vestibular glands located on either side of the urethra; secrete subtance that lubricates opening and may act as an antimicrobial
Internal female genitalia
- vagina
1) passageway for blood and mucosal tissue from uterus during woman’s monthly period
2) intercourse
3) passageway for childbirth + hold sperm? < _ <
4) leads from introitus (its external opening) to cervical portion of uterus - uterus
1) nourish developing fetus prior to brith\
2) fertilized ovum devleops
3) 3 layers starting with innermost – endometrium (lining), myometrium (muscular layer), and perimetrium (outer covering - continuous with pelvic peritoneum)\
4) endometrium proliferates (thickens) and sloghs off in response to cyclic hormonal changes
5) cervix – narrow, lower portion of uterus that opens into vagina - fallopian tubes
1) aids in the delivery of sperm to the egg.
2) aids in the passage of a fertilized egg into the uterus.
3) 2 of them; fertilzation usually occurs in distal third of fallopian tubes - ovaries
1) produce eggs for fertilization (ovum mature and release)
2) make hormones estrogen and progesterone + androgen hormones [help with prepubertal growth spurt, pubic + axillary hair growth, and activating of sebaceous glands]
3) releases egg @ day 14 of 28 day cycle in middle of menstrual cycle
4) each month, days 6-14 of cycle, FSH causes follicles in one of your ovaries to mature then at day 14 - a sudden surge in LH causes ovary to release an egg (ovulation)
5) as egg travels down fallopian tube, the progesterone rises to help prepare uterine lining [usually second half]
6) estrogen production is greatest in first half
Average menstrual cycle
- lasts 27-30 days
3 phases
1) follicular (starts on the first day of your period and lasts for 13 to 14 days, ending in ovulation [ovarian cycle]) /proliferative phase (same as above) [during this phase, the ovary and adrenal glands each contribute 50% of progesterone production]
* high FSH levels cause follicle and ovum maturation (follicular phase)
* also estogren produced by maturing follicle causes endometrium to proliferate (proliferative phase) and induces LH surge (from anterior pituitary d/t continued estrogen production) [just before ovulation] and progesterone production in granulosa layer responding to FSH (produce estrogen too) – granulosa important in oocyte growth + maturation [after ovulation, these follicular cells originate from corpus luteum (granulosa lutein cells)] + some of them follow with egg (cumulus cells)
2) luteal phase/secretory phase (14-28 days of cycle)
* estrogen maintains thickened endometrium
* development of corpus luteum (luteal phase) – makes estrogen and progesterone (make ideal environment for fetus to grow)
* progesterone causes it to develop blood vessels + secretory
glands (secretory phase)
3) ischemic/menstrual phase (28th day of cycle, lasts few hours if fertilized egg has not ferilized)
* corpus luteum degenerates
* boht hormones drop sharply
* starved endometrium degenerates and sloughs off => menstruation
Cyclic changes in hormones (female)
1) thinning and thickening of vaginal epithemlium
2) thinning and thickening of cervical secretions
3) change in basal body temperature
Before puberty and after puberty, breast structure
- both male and female have a small underdeveloped nipple w/ some fatty and fibrious tissue + few ductlike structures under areola (lack of progesterone and estrogen production prevents further development of male breast)
- At puberty, a variety of hormones
1) estrogen, puberty, prolactin, GH, insulin, cortisol
cause female breast into system glands and ducts capable of producing milk
Lobe
- basic functional unit of female breast
- system of ducts branches from nipple to milk-producing units called lobules
- each lobule has aveolar cells (convoluted spaces lined w/ epithelial cells that secrete milk and subepithelial cells that contract to move milk into system of ducts to l/t nipples)
- 15-20 lobes each breast; separated and supported by cooper ligaments
Milk production
- in response to prolactin, hormone secreted by alveolar epithelial cells in larger amounts after childbirth
- milk ejection controlled by oxytocin, which causes contraction of myoepithelial cells
male reproductive system
- produce male gametes (sperm)
- deliver them to female tract
external male genitalia
1) testes (produce sperm + produce testosterone
2) epididymides (rrow, tightly-coiled tube that is attached to each of the testicles (the male sex glands that produce sperm). Sperm cells (male reproductive cells) move from the testicles into the epididymis, where they finish maturing and are stored)
3) scrotum (protect testes, thermoregulation [few degrees below average body temp to maintain sperm production] – 33.8 to 35.6 F
* contracts in cold; relax in warm
4) penis
* cylindrical organ consist of 3 longitudinal compartments [two corpora cavernosa and one corpus spongiosum] + urethra (which runs through spongiosum)
* both tissue types have erectile tissue
* shaft + tip (glans) – glans have sebaceous glands
* both sperm and urine are never in the urethra at same time
internal genitalia
1) vas deferens - coiled tube that carries sperm out of testes
2) ejaculatory duct - (delivers sperm into urethra – adding secretions and addtives from prostate necessary for sperm function)
3) prostatic and membranous sections of urethra (part of urethra that carries seminal fluid through prostate gland that produce semem)
4) seminal vesicles (glands that produce fluids that will turn into semen or can be called vescular glands) [this 1st then ejaculatory duct]
5) prostate gland (produce the fluid that nourishes and transports sperm (seminal fluid))
6) cowper glands or bulbourethral glands (right under prostate) [exocrine] -
* secrete glycoproteins during sexual stimulation (lubricant)
* alkaline mucus-like fluid that neutralize trace of acidic urine in urethra
