Reproductive System Flashcards
What determines internal male or female organs as the body develops
Testosterone and anti-Mullerian hormone or the lack of them
What happens during biopotential development internally for males
Gonadal medulla forms a testis and the Wolffian duct forms the epididymis, vas deferens, and seminal vesicle
What happens during biopotential development internally for females
The gonadal cortex forms the ovaries and the Mullein duct becomes the Fallopian tube, uterus, cervix, and upper 1/2 of the vagina
What happens during biopotential development externally for males
The genital tubercle forms the glans penis, the urethral folds and grooves form the shaft of the penis, and the labioscrotal swellings form the shaft of the penis and scrotum
What happens during biopotential development externally for females
The genital tubercle forms the clitoris, the urethral folds and grooves form the labia minor, opening of the vagina, and urethra, and the labioscrotal swellings form the labia majora
What gene determines sex
SRY gene in the sex-determining region of the Y chromosome
What is the main function of the reproductive system
Procreation
How is the reproductive system controlled
Hormonally via the hypothalamic anterior pituitary-gonadal (HPG) axis
What are the gonads
Males = testes
Females = ovaries
What hormone does the hypothalamus release in the reproductive system
Gonadotropin releasing hormone (GnRH)
What hormones does the anterior pituitary secrete for the reproductive system
Gonadotropics (luteinizing hormone and follicle stimulating hormone)
What is the broad function of luteinizing hormone (LH)
Steroid synthesis (steroidgenesis)
What is the broad function of follicle stimulating hormone (FSH)
Gamete production (gametogenesis)
What is the function of the gonads
To produce sex hormones (androgens, estrogen, and progesterone) and gametes
Where else to sex hormones come from
The adrenal cortex
What types of feedback do GnRH and LH/FSH operate on
Short and long loop negative feedback
Which sex produces which sex hormones
Both sexes produce all 3 (androgens, estrogen, and progesterone)
What use do androgens serve
The are converted in peripheral tissues to more potent DHT (dihydrotestosterone) by 5-alpha-reductase
What converts androgens to estrogens
Aromatase enzyme within both testes and ovaries
What 2 cells in the testes are involved in spermatogenesis
Leydig (interstitial) and sertoli
What do the leydig cells do
Receive LH and produce testosterone
What does androgen-binding protein do
Binds to testosterone to concentrate in lumen for spermatogenesis (because androgen is a steroid hormone and would otherwise diffuse through the membrane)
What controls male secondary sex characteristics
Androgens
What are primary sexual characteristics
Internal sexual organs and external genitalia
What are secondary sex characteristics
Traits (other than genitalia) that distinguish males from females (general body shape, muscle development pattern, body hair and beard, deep voice, and male sexual behavior/libido)
What are the two cycles of females reproduction
The ovarian (menstrual) cycle and the uterine cycle
What is the ovarian cycle
Changes within the follicles of the ovary (24-35 days, 28 day average)
What is the uterine cycle
Changes within the endometrial lining of the uterus to prep for potential pregnancy
What is the endometrium
The inner lining of the uterus
What is the basic overview of the female reproductive cycle (7 steps)
1) Follicle develops
2) LH stimulates follicular thecal cells to produce androgens
3) FSH stimulates follicular granulose cells to convert androgens to estrogens
4) Estrogens stimulate follicle development and endometrium growth
5) Rapid estrogen rise leads to ovulation
6) Follicular cells become corpus luteum that secretes progesterone (tells uterus to prepare for implantation)
7) If no implantation, meses (endometrail lining sheds)
What are the 3 phases of the ovarian (menstrual) cycle
Follicular phase, ovulation, and luteal phase
What 3 broad things happen in the follicular phase
Follicle development, growth of granulosa cells (secrete estrogen), and oocyte maturation
What broadly happens during ovulation
The mature follicle bursts to release the oocyte
What broadly happens during the luteal phase
The ruptured follicle develops into the corpus lute and secretes progesterone and estrogen
What are the 3 phases of the uterine cycle
Menses, proliferative phase, and secretory phase
What is menses
If implantation doesn’t occur, the endometrium is shed causing the uterus to bleed
What broadly happens during the proliferative phase
The endometrium thickens (develops more blood vessels) in preparation for pregnancy
What broadly happens during the secretory phase
The corpus luteum secretes progesterone that promote implantation
What does LH produces by the ovaries do in females
Received by thecal cells (similar to male Leydig cells) that will then secrete androgens
What does FSH produced by the ovaries do in females
Stimulates follicular development because androgens produced by the thecal cells diffuse into granulosa cells (similar to male sertoli cells) and aromatase converts those androgens to estrogen
What type of feedback to gonads have in females
Usually negative between GnRH, FSH, and LH, but becomes positive when estrogen rises rapidly above a threshold for 36 or more hours (days 12-14)
What happens when gonadal steroid feedback in females changes to positive feedback
It stimulates LH release (LH surge) that triggers ovulation
What is happening during days 0-7 of the female cycle
Beginning of the follicular phase in the ovarian cycle (follicle developing) and menses (endometrium shedding from previous pregnancy) in the uterine cycle
What hormone control happens during early follicular phase
FSH stimulates follicular development (follicular granulosa cells produce estrogen), LH stimulates thecal cells to produce androgens (diffuses into granulosa cells where aromatase converts androgens into estrogen), and estrogen inhibits GnRH, LH, and FSH via negative feedback
Where are thecal and granulosa cells on a developing follicle
Thecal cells are on the outside and granulosa cells are on the inside
What is happening during days 7-14 of the female cycle
End of the follicular phase in the ovarian cycle (follicle mature, ready for ovulation and estrogen increasing), and the proliferative phase in the uterine cycle (endometrium grown to prepare for possible pregnancy)
What hormonal control occurs in the late follicular phase
Rapid increase in estrogen changes from negative feedback to positive which increases the secretion of LH (LH surge) that triggers ovulation (basis for ovulation test)
What hormonal control happens during ovulation
About 36 hours after the LH surge, the follicle ruptures and releases the mature oocyte (ovul), and the theca and granulosa cells of the follicle become luteal cells
What happens during days 14-21 of the female cycle
Luteal phase of the ovarian cycle begins (corpus luteum forms from follicle and produces progesterone and some estrogen) and the secretory phase of the uterine cycle (endometrial secretions promote implantation of fertilized ovul)
What hormonal control happens during the early to mid-luteal phase
Corpus luteum secretes progesterone and estrogen to exert negative feedback on hypothalamus (FSH and LH still low so that another follicle doesn’t develop while waiting for implantation), and the endometrium is stimulated by progesterone to further develop
What happens during days 21-28 of the female cycle
Late luteal phase of the ovarian cycle (corpus luteum degenerates and stops hormone production) and secretory phase of the uterine cycle
What hormonal control happens during late luteal phase
If no implantation, the corpus luteum degenerates (bc/ lack of progesterone kills endometrium), menses (sloughing of dead endometrium), and FSH and LH secretion resumes to start next cycle
What happens after implantation of a fertilized egg
About 5-7 days after, the fertilized egg (blastocysts) secretes enzymes that allow it to burrow into the endometrial wall, the placenta develops to secrete human chronic gonadotropic (hCG), and hCG maintains corpus luteum which continues to secrete progesterone and estrogen
What controls female secondary sex characteristics
Estrogen controls breast development and distribution of body fat, and adrenal androgen control growth of pubic and axillary (armpit) hair, and sex drive (libido)
What are the 3 characteristics of fertilization
Egg can only be fertilized for 12-24 hours after ovulation, it normally happens in the distal Fallopian tube, and the blastocysts travels via cilia and implants into the uterine wall
What is an ectopic pregnancy
Implantation occurs somewhere outside of the uterus (usually fallopian tube but can be body cavity) –> Non viable pregnancy
What are the 5 kinds of contraceptives
Abstinence, sterilization, barrier methods, prevent implantation, and hormonal treatments
What are the 2 kinds of abstinence
Total abstinence and the rhythm method (abstinence during periods of female fertility using calendar or body temp)
When is female body temp increased in the female cycle
12-24 hours after ovulation
What are the 2 kinds of sterilization
Tubal ligation (typing off and cutting Fallopian tubes) and vasectomy (tying and clipping vas deferens)
How long does it take for a male to actually be sterile after receiving a vasectomy
About 3 months
What are the 2 kinds of barrier contraceptives
Diaphragm/cervical cap or sponge for females, and condoms for males
What contraceptives prevent implantation
Intrauterine devices (IUDs), copper can kill some sperm but fertilization can occur
What are the 4 types of hormonal contraceptives
Oral contraceptives (usually progesterone/estrogen to mimic the luteal ovarian phase to prevent rise in LH and FSH), infections (Depo-Provera), vaginal contraceptive ring (NuvaRing), and the morning after pill (PlanB)
How does PlanB work
Delays or prevents ovulation (not implantation, and it won’t disturb and implanted egg because it’s not an abortion pill)
What are the most affective forms of contraception (<1%)
Injections, IUDs, sterilization, and total abstinence
