Reproductive Physiology Flashcards
Defined by sex chromosomes
Genetic sex
Defined by presence of ovaries/testes
Gonadal sex
Defined by characteristic of internal genital tract and external genitalia
Phenotypic sex
Internal genital tract in males:
prostate, seminal vesicle, vas deferens, epididymis
Internal genital tract in females
fallopian tube, uterus, upper 1/3 of vagina
External genitalia in males:
scrotum, penis
External genitalia in females
clitoris, labia minora & majora, lower 2/3 vagina
Secreted by Sertoli cells to cause atrophy of Mullerian ducts
Antimullerian hormone
Secreted by Leydig cells for growth of Wolffian ducts
Testosterone
Which substance is suspected to initiate pubery?
Melatonin
What conditions may inhibit the onset of puberty?
stress, malnutrition
What is the first event in puberty in males, and in females?
Males: testicular enlargement
Female: breast enlargement (thelarche)
Which hormone causes adrenarche (pubic hair, axillary hair development) in females?
Adrenal androgens
What is the offshoot of the genital tubercle in males and in females?
Males: Glans penis: Females: Glans clitoris
Males: Corpus cavernosum and spongiosum: Females: vestibular bulbs
What is the offshoot of the urogenital sinus in males and in females?
Males: bulbourethral (Cowper’s) glands: Females: Bartholin’s (greater vestibular) glands
Males: Prostate gland: Females: Skene’s (urethral and paraurethral) glands
What is the offshoot of the urogenital folds in males and in females?
Males: ventral shaft of the penis (penile urethra): Females: labia minora
What is the offshoot of the labioscrotal swelling in males and in females?
Males: scrotum: Females: labia majora
3 forms of androgens:
Androstenedione, testosterone, dihydrotestosterone
Most powerful form of androgen:
Dihydrotestosterone
Androgens:
Blood transport: bound to _____ and _____
Liver degradation to ______ and _____
Excretion into the feces and urine.
bound to Albumin and sex-hormone binding globulin
liver degradation to Androsterone and DHEA (dehydroepiandrosterone)
Stimulates the Sertoli cell for spermatogenesis
FSH
Stimulates the Leydig cells to secrete testosterone
LH
Testosterone vs Dihydrotestosterone
Buzz words: hair, baldness, sebaceous glands, penis, scrotum, prostate = dihydrotestosterone
All others caused by testosterone
What is responsible for sperm production?
seminiferous tubules
What is responsible for sperm maturation and motility?
epididymis
What is responsible for sperm storage?
Vas deferens
What is responsible for sperm nutrition (fructose and prostaglandins)?
seminal vesicle
What is responsible for semen alkalinity (spermine)
prostate gland
What is the function of the bulbourethral gland/Cowper’s glands?
supplies mucus
Trace the path of the semen:
SEVEN UP (Think: it's usually up by 7AM to remember the mnemonic) Seminiferous tubules Epididymis Vas deferens Ejaculatory ducts (Nothing) Urethra Penis
What is the temperature of the testes?
1-2 degrees celcius cooler than body temperature
What is responsible for the temperature in the testes?
countercurrent exchange of the testicular vessels
What is the duration of spermatogenesis?
64 days
What is the sperm production per day?
128 million
Activation of sperm in the female genital tract for 4-6 hours is called:
Capacitation
What is the enzyme that converts androstenedione to testosterone?
17 beta-hydroxysteroid dehydrogenase
What is the enzyme that converts testosterone to dihydrotestosterone?
5 alpha reductase
What is the 5 alpha reductase inhibitor used for male pattern baldness and BPH?
Finasteride
What is responsible for erection?
parasympathetic stimulation (uses Nitric oxide aside from Ach)
What do you call the movement of semen from the vas deferens ampulla to the internal urethra?
Emission
What do you call the movement of semen from the internal urethra to the environment?
Ejaculation
After ejaculation, sexual excitement disappears for 1-2 minutes, this is called:
Resolution
Cell which determines the sex of the baby:
Sperm cell
Part of the sperm cell that contains hyaluronidase, proteolytic enzymes
Acrosome
Acrosome comes from which organelle?
Golgi apparatus
Definition of low sperm count
Sequelae of cryptorchidism
Infertility, testicular CA
The effect of this is loss of body hair, musculature, thick bones, decreased libido
Castration after puberty
Vestigial remnant of 3rd eye; secretes melatonin which is involved in reproduction and sex drive
Pineal gland
Ovum surrounded by single layer of granulosa cells, which provides nourishment to ovum and secretes inhibiting factor to keep ovum in prophase
Primordial follicle
Part of the primary follicle that secretes estrogen and progesterone
Theca interna
Part of the primary follicle that becomes the capsule of the follice
Theca externa
The size of a mature follicle
1 - 1.5cm
LH surge causes increase in follicular size, decreased estrogen and increased progesterone leading to:
Ovulation
What causes the expulsion of the ovum?
Theca externa releases proteolytic enzymes causing wall swelling and rupture
What forms the corpus luteum?
Granulosa cells and theca cells luteinized to form luteal cells which become the corpus luteum
Form of estrogen secreted by the adrenal cortex and theca cella, seen in post-menopause
Estrone
Form of estrogen secreted by the ovaries, seen during reproductive years
Estradiol
Form of estrogen secreted by the placenta, seen during pregnancy
Estriol
Enzyme that catalyzes conversion of androstenedione to estrone and testosterone –> estradiol
Aromatase
Estrogen vs Progesterone:
lowers uterine threshold to contractile stimuli
Estrogen
Estrogen vs Progesterone:
raises uterine threshold to contractile stimuli during pregnancy
Progesterone
Estrogen vs Progesterone:
Inhibits osteoclasts
Estrogen
What is the normal length of the menstrual cycle?
28 +/- 7 days
What phase of the menstrual and endometrial cycle does estrogen predominate?
Follicular phase, Proliferative phase
What phase of the menstrual and endometrial cycle does progesterone predominate?
Luteal phase, Secretory phase
What causes menstruation?
Cessation of progesterone
During menstruation, levels of estrogen, progesterone, FSH and LH are all:
Decreased
During the follicular phase, which hormones increase and which decrease?
Estrogen, FSH: increase
Progesterone, LH: decrease
During ovulation, female hormones increase except:
Progesterone (estrogen, FSH, LH decrease)
During luteal phase, female hormones decrease except:
Progesterone (estrogen, FSH, LH increase)
Produced by ovarian granulosa cell and inhibits FSH secretion from anterior pituitary
Inhibin
Produced by ovarian granulosa cell and stimulates FSH secretion from anterior pituitary
Activin
Average age menarche and menopause
Menarche: 13 y/o
Menopause: 45 y/o
Number of lifetime mature follicles
400 follicles
Peak of sexual desire
Just before ovulation
Fertilized ovum implanting on uterus
Blastocyst
Pregnancy: Egg has ____ hours to be fertilized
24 hours
Pregnancy: Sperm has ____ days to fertilize the egg
1-5 days
Pregnancy: normal site of fertilization
Ampulla of oviduct
Cells of the blastocysts that digests and liquefies the endometrium for invasion
Trophoblast
Cytotrophoblast - inner; Syncitiotrophoblast - outer
Nutrient-rich endometrium invaded by trophoblasts
Decidua
Hormone produced by the syncitiotrophoblast that rescues the corpus luteum
B-HCG
Growth hormone of pregnancy; index of placental well-being; promotes insulin resistance in the mother
Human chorionic somatomammotropin/ Human placental lactogen