3C. Human Reproductive Cycles are controlled by Hormones Flashcards
lies deep in the brain, protected by the sphenoid bone and attached to the brain by the hypothalamus
pituitary gland
secretes luteinizing hormone and follicle-stimulating hormone, which are instrumental in governing the reproductive system
anterior pituitary gland
TRUE OR FALSE: male hormones exert control over the rate of sperm production and the secretion of testosterone
true
stimulates the Leydig cells residing between the seminiferous tubules, causing the release of testosterone
luteinizing hormone (LH)
luteinizing hormone (LH) is also called ___
interstitial cell stimulating hormone (ICSH)
puberty in males brings about secondary sex characteristics, driven by testosterone; these include ___
- skeletal and muscle growth
- body and facial hair
- changes in the larynx causing a deeper voice
- thicker skin
- increased oil production
plays a role in male pattern baldness; formed when testosterone is converted by the enzyme 5-alpha reductase
dihydrotestosterone (DHT)
TRUE OR FALSE: male pattern baldness, influenced by the mother-inherited DHT sensitivity gene and individual DHT hormone levels, can result in varying hair loss patterns across generations, even when fathers and grandfathers exhibit baldness
true
secreted by the anterior pituitary gland in both sexes; indirectly stimulates spermatogenesis in males
follicle-stimulating hormone (FSH)
binds available testosterone and maintains it in high concentration near the seminiferous tubules
androgen-binding protein (ABP)
if blood testosterone rises too high, it prevents the release of ___ from the hypothalamus
gonadotropin-releasing hormone (GnRH)
two interrelated cycles in the female reproductive cycle
ovarian and uterine cycles
controls egg maturation and ovulation
ovarian cycle
prepares the endometrium for possible pregnancy, leading to menstrual flow if fertilization does not occur
uterine cycle
beginning of uterine cycle where there is shedding of the old endometrial lining; 3 to 7 days
menstruation
regeneration of the endometrial lining driven by rising estrogen levels
proliferative phase
FSH stimulates follicle maturation in the ovaries; 6 to 13 days
preovulatory phase
triggered when there is a surge in LH, releasing an ovum
ovulation
lasts 14 days, during which the corpus luteum forms, secreting progesterone to maintain the endometrial lining in preparation for implantation
postovulatory phase
TRUE OR FALSE: if fertilization does not occur, the corpus luteum degenerates, progesterone and estrogen levels drop, and the endometrial lining is shed, restarting the cycle
true
TRUE OR FALSE: lifestyle has a profound effect, as can be seen in postpubescent elite female athletes
true
one year after the last menstrual flow; results from a decline in ovarian hormone production
menopause
