Endocrinology Flashcards
In female endocrinology, what are the three groups??
Gonadotropins
Sex steroids/prostaglandins.
Mammotropins
What do gonadotropins do?
Stimulate ovary to produce
What do sex steroids/ prostaglandis do?
Direct control of the reproductive state
What do mammotropins do?
Involved in lactation.
What is extremely impoarnt in animal management?
Lactation!
What are the two gonadotropins?
Luteinizing Hormone (LH)
Follicle stimulating hormone (FSH)
What does the Luteinizing hormone (LH) gonadotropin do?
-Causes ovulation
-Stimulates final growth of follicles
-Also stimulates corpus Luteum.
LH is involved in what?
The last stage of follicle development and the last stage of ovulation. Think L equals last.
What does the Follicle stimulating hormone (FSH) Gonadtropin do?
-Stimulates all stages of follicle growth, especially early periods!
Where is FSH produced by?
The pituitary gland.
FSH is involved in which state of most things?
The first stage of most things
Think F = first
L = last.
What are the three sex steroids/prostaglandins?
Progesterone
Estrogen
Prostaglandin
What does progesterone do?
Responsible for maintenance of pregnancy
Also prepares to get pregnant.
Inhibits gonadotropin secretion.
Where is progesterone produced?
In most animals, the Corpus Luteum!
In some, the placenta (Horse)
What is the overarching purpose of progesterone? Why?
Prepare and maintain pregnancy.
It reduces LH and FSH and quiets the system!! You dont want follicles to develop when she is pregnant!!
Of the sex steroids, what does estrogen do?
-Prepares the reproductive tract to be bred.
-generally responsible for the estrus cycle
-Responsible for female mating behavior
-Prepares female for breeding and parturition.
-Stimulates pre-ovulatory surge of gonadotropins.
When and where is estrogen produced?
Produced by growing follicles, placenta, and embryos.
-Right before giving birth, estrogen start to be produced by the placenta.
What is the effect of estrogen on gonadotropins?
-It has both a positive and negative effect on gonadotropins
-We would say overall effect on gonadotropins is positive.
When estrogen is high, what happens?
LH and FSH is high!
Of the sex steroids/prostaglandis, what is Prostaglandin?
-Primarily produced by the uterus.
-Responsible for luteal regression
-Destroys the CL.
-Causes uterine contractions at birth.
What are the two mammotropins?
Prolactin
Oxytocin
Describe what Prolactin is.
Produced in the pituitary gland.
Stimulates production of milk
How does prolactin contribute to lactation?
It stimulates production, but has NOTHING to do with milk release.
Describe Oxytocin.
-Produced by uterus and hypothalamus
-Stimulates milk excretion
-Stimulates Uterine contractions.
Why might oxytocin stimulate uterine contractions??
You want milk to be available immediately when the baby is born.
What is Parturition?
Birth!
Give a rundown of the female cycle.
Puberty, into the estrous cycle, into gestation, into birth, lactation, weaning, into either the estrous cycle again or rebreeding.
Why is the cycle a little bit different for each animal?
In some, the female is rebred before the baby is weaned. Some are right after, some are given a couple of cycles before they are rebred.
WHat is the period after birth often called?
Post-Partum period.
Describe what a reproductive cycle entails.
Invovles interactions between the ovary, uterus, mammary gland, and brain.
these organs communicate using hormones and nerves.
Define Puberty
The age at which an animal is capable of adult reproductive function.
What does puberty look like in males?
Libido, mating, and production of fertile sperm.
What does puberty look like in females?
Estrus, production of fertile eggs, maintenance of pregnancy.
Generally, what is the last function to muture during puberty?
The brain and the production of gonadotropins.
Specifically LH!
What is the least understood part of the cycle of reproduction?
Puberty!
What is first capable of reproducing?
Gonads before the brain!!
WHat is a gonad?
In females the ovaries.
In males the testicles.
What is the biggest limiting factor for puberty to start? Why?
Luteinizing Hormone (LH)
The brain takes longer to develop and produce LH than the gonads take to produce their hormones.
What is the estrous cycle?
Repeatable sequence of events that results in female becoming sexually receptive.
What is the point of the estrous cycle? Explain.
For the female to get pregnant. If she doesnt, it will repeat until she does.
What is estrus?
Period of sexual receptivity.
Explain what happens hormonally during estrus.
Estrogen is high and progesterone is low.
High estrogen causes preovulatory surge of gonadotripins.
Explain ovulation.
LH surge causes ovulation.
The follicles release eggs
The estrogen decreases
CL (Porpora lutea) form.
The CL produces progesterone.