Lecture 19 - Puberty, Estrous, Pregnancy Flashcards
What is Puberty?
When an animal reaches a level of physiological maturity that permits conception
What are 2 major influencing factors of puberty?
- age (genetics and environment)
- weight (genetics)
What are the events of puberty that males and females see?
Females - first estrous and ovulation
- LH, FSH, estrogen at high enough concentrations
- follicular growth, oocyte maturation, ovulation
Males - production of sperm capable of fertilizing an oocyte
What are the 4 phases of the estrous cycle?
Estrus
Metestrus
Diestrus
Proestrus
What takes place during estrus?
Sexual receptivity
High estrogen from the preovulatory follicle
Behavioral estrus
What are the symptoms of estrus
Sexual receptivity
Urinating, winking vulva, swollen vulva, interest in males, mounting of other females
What is Metestrus
Formation of the CL and increased progesterone production
What is diestrus?
Progesterone predominate from CL
If pregnant - CL remains and functions until progesterone
Not pregnant - PGF2a from the endometrium indices literal regression
What is proestrus
Interval between regression of CL and next estrus
LH increasing, growth of preovulatory follicles, increasing estrogen
What are the types of Estrous?
Polyestrus
Seasonally polyestrus
Monestrus
Induced or “reflex” ovulator
What is polyestrus?
Cycle continuously
Cows, pig, mice
What is Seasonally polyestrus?
Ovulate during certain times of the year
- short day breeders (fall/winter) sheep, goats, deer
- long day breeder (spring) horses
What is monestrus?
Cycle once yearly
Dog
What is induced/ reflex ovulator?
Copulation stimulates ovulation
LH released with mounting and intromission
Cat, llama, rabbit
What is a viviparous gestation?
Live birth, fetus develops in the uterus
