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What is the classification of Estradiol by biochemical signiature?
Steroid
What is the female target tissue of Estradiol?
Hypothalamus, entire reproductive tract and mammary gland
What is the classification of GnRH by biochemical signiature?
Neuropeptide
What is the female target tissue of GnRH?
Pituitary, anterior lobe
What is the source of Luteinizing Hormone?
Anterior pituitary
What is the male target tissue of Luteinizing Hormone?
Testis
What is one reproductive hormone derived from unsaturated fatty acids?
Prostaglandin F2 Alpha
What molecule are all steroid hormones derived from?
Cholesterol
What hormone or molecule is the immediate precursor to estradiol?
Testosterone
The hypothalamus is inherently female. The hormone ___, converted to ___ in the brain, defeminizes the hypothalamus, eliminating the ___ in males.
Testosterone, estradiol, LH surge center
What prevents defeminization of the hypothalamus in females?
Alpha-fetoprotein binds to estradiol and prevents it from crossing the blood-brain barrier
What is the first change that must occur to initiate the onset of puberty in mammals?
The hypothalamus must first secrete Gonadotropin Releasing Hormone
What are the two management factors that might decrease the age at puberty onset in female animals?
Exposure to a large group of females, exposure to a male, season born
Describe reproductive cyclicity in polyestrous animals.
Having more than one cycle a year
Describe reproductive cyclicity in seasonal polyestrous animals (both types).
Long day: animals who cycle during seasons with long days (spring, summer). Short day: animals who cycle during seasons with short days (fall, winter)
Describe the reproductive cyclicity in monoestrous animals.
Animals who cycle only once a year (on average)
What are the two major phases of the estrous cucle and what are the dominant steroid hormones during each phase?
Luteal phase - progesterone
Follicular phase - estradiol
What are the 4 stages of the estrous cycle?
Metestrus, diestrus, proestrus, and estrous
What is the fundamental endocrine condition that results in anestrus?
GnRH is not released properly from the hypothalamus
Which neurons in the hypothalamus convert to environmental signal of change in daylight hours to stimulate/inhibit the release of gonadotropin releasing hormone?
RFRP neurons or kisspeptin neurons
There are three main stages of endometrial development during the menstrual cycle. Identify each stage and identify the phase of the menstrual cycle each occurs during.
Proliferation - follicular phase
Secretory - luteal phase
Menstruation - menses phase
Estradiol is (positive/negative) on the surge center of the hypothalamus, but (positive/negative) on the release of FSH from anterior pituitary.
Positive, negative
Use the words positive, negative or no effect to describe how inhibin from a developing follicle affects the following:
a. Release of follicle stimulating hormone from the anterior pituitary
b. Release of luteinizing hormone for the anterior pituitary
c. Release of gonadotropin releasing hormone from the hypothalamus
Negative, no effect, no effect
What hormone released from the follicle stimulates the preovulatory luteinizing hormone surge?
Estradiol
Explain why the first wave of follicles in the cow all become atretic rather than leading to ovulation.
An influx of progesterone prevents follicular dominance, causing all follicles to become atretic