Midterm Flashcards
Hormone released: hypothalamus
Gonadotropin releasing hormone (GnRH) and oxytocin
Hormone released: posterior pituitary
Oxytocin
Hormone released: anterior pituitary
Gonadotropins: FSH (follicle stimulating hormone) and LH (luteinizing hormone)
Hormone released: testes
Androgens (testosterone)
Hormone released: ovaries
Estrogen and progesterone
Hormone released: placenta
hCG (human chorionic gonadotropin), estrogen, and progesterone
Target tissue/organ: GnRH from the hypothalamus
Anterior pituitary
Target tissue/organ: Oxytocin from the hypothalamus
Posterior pituitary
Target tissue/organ: Oxytocin from the posterior pituitary
Uterus/mammary glands
Target tissue/organ: FSH and LH from the anterior pituitary
Gonads (ovaries and testes)
Target tissue/organ: Androgens from the testes
Gonads, skin, bone, and muscles
Target tissue/organ: Estrogen and progesterone from the ovaries
Gonads, skin, bone, and muscles
Target tissue/organ: hCG, estrogen, and progesterone from the placenta
Corpus luteum, placenta, fetus
Gonadotropin Releasing Hormone (GnRH) function
Regulates anterior pituitary
hormones for gonads
Hypothalamus oxytocin function
Stimulates uterine muscle
contractions, and stimulates
release of milk during
breastfeeding
Posterior pituitary oxytocin function
Stimulates uterine muscle
contractions, and stimulates
release of milk during
breastfeeding
Anterior pituitary FSH and LH function
Egg and sperm production, sex
hormone (testosterone, estrogen
& progesterone) production
Androgens from the testes function
Stimulate male sex characteristics
Estrogen and progesterone from ovaries function
Stimulate female sex characteristics
hCG, estrogen, and progesterone from the placenta function
Development of the fetus, and
maintenance of pregnancy
Hypothalamus
- located at the base of the brain
- secretes hormones that stimulate or suppress the release of hormones in the pituitary gland
- (in addition to controlling water balance, sleep, temperature, appetite, and blood pressure)
Pituitary gland
- below the brain
- no larger than a pea
- controls many functions of the other endocrine glands.
Ovary
- on both sides of the uterus
- below the opening of the Fallopian tubes - contain the egg cells necessary for reproduction
- produce estrogen and
progesterone.
Testes FUNCTION
produce testosterone and sperm
Placenta
- connects fetus to the wall of the mother’s uterus
- grows in the wall of the uterus and is attached to the fetus within the
uterine cavity by the umbilical cord. - produces chorionic gonadotropin which
stimulates the corpus luteum to continue releasing progesterone during early pregnancy. - produces estrogen and progesterone to maintain both the uterus and
placenta
Where is the pituitary gland?
Below the hypothalamus
What is the HPG? Describe
Hypothalamic-Pituitary-Gonadal Axis; negative feedback loop
- Hyp produces GnRH (Gonadotropin Releasing Hormone)
- Anterior pituitary releases FSH and LH after stimulation by GnRH
- FSH and LH promote production of testosterone, estrogen, and progesterone depending on sex, these hormones feedback to the hyp to shut down the process
What hormone predicts ovulation?
LH; huge spike right before ovulation
What hormone is only produced when pregnant and thus is used to detect pregnancy?
hcG; human chorionic gonadotropin; produced only when pregnant (by placenta)
XY sex determination pathway
Y chromosome has srYgene → srYgene produces TDF hormone (testis determining factor) → acts on primitive gonads to produce MIS (Mullerian Inhibiting Substance) to prevent female structures // produces testosterone to create Wolffian ducts and thus male structures
XX sex determination pathway
No testosterone → no development of Wolffian duct // no MIS → development of Mullerian ducts and thus female structures
What is the one relevant example of a positive feedback loop?
Oxytocin release during labor; Stretching of cervix = release of oxytocin = stretching of the cervix, cyclic
First fourteen days of menstrual cycle?
Follicular phase; follicular growth and egg maturation
Anterior pituitary produces which two gonadotropins?
FSH (follicle stimulating hormone) and LH (luteinizing hormone)
How long does the corpus luteum stay intact?
Until the second trimester
What prevents uterine lining from shedding during pregnancy?
High progesterone and estrogen
Corpus luteum function
Produce progesterone to maintain uterine lining until the placenta can take over
What does the placenta produce?
hCG, progesterone, etc.
How long is a trimester?
13 weeks
How long is pregnancy?
~270 days; 38.5 weeks
Calcineuron
protein that helps sperm swim; can cause infertility if production gene is inhibited
Eppin
Nonhormonal male contraceptive pill; inhibits sperm motility
YCT529
male nonhormonal contraceptive pill; blocks vitamin a receptor, 99% affective in mice
Estrogen levels increase ___ by childbirth
30x
Parturition
Birth
Egg span
24-48 hours after ov unless fertilized
Sperm span
1-4 days
Pineal gland function
Melatonin secretion