quiz 3

Question 1

what are the four factors that affect the attainment of puberty? list or describe an example of each factor

Answer 1

1. hormonal: this relies on the desensitization of the tonic center of the hypothalamus to allow onset of puberty. This allows E2 to increase and GnRh surge
2. nutritional: animals (females) have to be at an optimum weight to go into puberty. If fed more lbs per day does not decrease puberty date but too little will prolong puberty date.
3. Genetic: the breed and age of animal causes this to fluctuate onset puberty. Angus males go into puberty at an earlier age than Herefords
4. environmental: one influence is the density of housing. If you have 3 females in a pen (pigs) puberty will be latter than if you have 10 females in a pen

Question 2

what type of feedback does estradiol have on the tonic center of the hypothalamus? What about the surge center

Answer 2

a negative feedback on the tonic

a positive feedback on the surge but when at optimum levels

Question 3

what hormone is secreted from the pineal gland and influences seasonal breeders

Answer 3

melatonin

Question 4

list two examples of why a mammal might experience anestrus

Answer 4

lactational

gestational

Question 5

list the 3 types of estrous cycles (these types are defined by when and how often cyclicity occurs)

Answer 5

polyestrous
monoestrous
seasonally polyestrus

Question 6

females do not generally exhibit estrous behavior or have a LH surge during the luteal phase because of neg feedback from ____________ to the brain and hypothalamus

Answer 6

progesterone

Question 7

list the 2 phases and the four stages of the estrous cycle
make sure to place stages in order with the appropriate phases
which sage makes up the majority of the estrous cycle

Answer 7

phases: follicular and luteal

stages:
proestrus
estrus
metestrus
diestrus  (majority of cycle)

Question 8

what city and state was kisspeptin discovered in

Answer 8

?