Lecture 7: Estrus cyclicity

Repro physiology

anestrus

a period of ceased cyclicity ex. lactation, pregnancy

estrous

the action of cycling (20-22 days)

estrus

standing heat (18-24 hrs)

polyestrus cycle

uniform polyestrus cycles throughout the year (humans, cattle, swine, cats, rodents)se

seasonally polyestrus

have estrus cycles seasonally (short day and long day breeders)

monoestrus

one cycle per year (dog)

pineal gland

where is melatonin secreted from

fat storage

what is leptins purpose

diestrus and proestrus

between what 2 stages does ovulation occur

1) proestrus

2) estrus

3) metestrus

4) Diestrus 

what is the order that the stages of estrous occur

proestrus and estrus

what stages are included in the follicular phase

metestrus and diestrus

what stages are included in the luteal phase

follicular

During this phase estrogen is the predominant hormone, the follicle is the dominant structure and increased LH and FSH levels

luteal

During this phase progesterone is the predominant hormone, the CL is the dominant structure and decreased LH and FSH levels

inhibin

during the follicular phase what causes LH to be “'low”

proestrus

during this stage estrogen is increasing, LH and FSH is increasing, endometrium size is increasing, GNRH is increasing

leutolysis

What causes the endometrium to begin to decrease in size after the cycle is over

estrus

during this stage estrogen has reached its peak, LH and FSH is increasing (surge), endometrium size is peaked, GNRH is peaked (surge)

anterior pituitary gland

where is FSH and LH released from

metestrus

during this stage estrogen is decreasing but progesterone is increasing, LH and FSH is deacreasing, endometrium size is at peak size, GNRH is decreasing

diestrus

during this stage progesterone is peaked, LH and FSH is decreasing, endometrium size is peaked, GNRH is decreasing

to prepare the uterus for fetal attachment

Why are progesterone levels high during the diestrus stage

menses

sloughing of the endometrium

menstrual cycle has endometrial sloughing

WHat is the difference between a menstrual cycle and estrous cycle