Exam 3 Lecture Notes Flashcards
estrus
Recurring period of sexual receptivity and fertility in many female mammals. During estrus, the female is in heat, indicating that she is ready to mate and can conceive.
what is estrus greek for?
frenzy
estrous
a period of sexual receptivity is determined by the interval from one estrus to the next
estrous cycle length: cow
21 days
estrous cycle length: ewe
16 days
estrous cycle length: sow
21 days
estrous cycle length: mare
21 days
when should you breed most animals?
when they are in heat
follicular phase
follicle growth, Graafian follicle forms
what happens to the follicle during estrus?
ovulation occurs
luteal phase
the corpus luteum is present
understand how blood flow is affected by the estrous cycle
blood flow goes down during estrus and then will increase during the luteal phase
understand how hormones are changed during the estrous cycle
estrogen increases before estrus, LH surge during estrus so ovulation can occur, FSH increases at the same time as LH, progesterone decreases during estrus and then increases after esturs (when the CL is formed), PGF2a increases before estrus to regress the CL
Hormonal Control of the Estrus Cycle
(diagram)
1. hypothalamus releases GnRH to the anterior pituitary
2. FSH and LH is released from the anterior pituitary and goes to the follicle
3. estrogen is produced by the follicle and goes to the hypothalamus, uterus, and anterior pituitary
4. the anterior pituitary released LH which goes to the follicle (ovulation occurs) and corpus luteum (form the CL)
5. CL produces progesterone which goes to the uterus, hypothalamus, and uterus
6. the uterus releases prostaglandin which will regress the CL
menses
menstruation (endometrial sloughing)
follicular phase of the menstrual cycle
menses (5 days) plus the proliferative phase (5 days)
luteal phase during the menstrual cycle
secretory phase (14 days), CL present
________ us needed for cycling, without it no cycling would occur (how seasonal animal stop cycling out of season)
GnRH
the estrous cycle: estrogen
high during heat, the animal will show signs of estus
___________ has a positive feedback mechanism to make LH surge
estrogen
the estrous cycle: LH
ovulation hormes, a surge of LH causes ovulation to occur