Puberty and the female reproducive system

What is the definition of puberty?

The ability to accomplish reproductive in males and females

Puberty should be considered a ……. that occurs over time, not a ….. event

progress, single.

What is needed to stimulate FSH and LH

GnRH

During puberty what must be produced at specific intervals and amounts and why?

GnRH, to simulate production of FSH and LH.

T or F Animals show signs of heat on the first ovulation

False, its the second

What is the most applicable definition of onset female puberty.

When an animal can carry a pregnancy without complications. Particular body size and level of fat to carry pregnancy and lactation is possible.

Describe the female onset of puberty

1.) showing estrous (heat) - behavior.

2.) Ovulates (requires examination of ovary to determine)

3.) can carry pregnancy without complications (most applicable definition)

Describe the Male onset of puberty

1. Behavioral signs are manifested - erection, mounting

2. Age at first ejaculation (very low concentration of spermatozoa)

3. Spermatozoa are present in the ejaculate

4. The ejaculate has enough spermatozoa to fertilize a female (most applicable definition)

What is the most applicable definition of onset male puberty

The ejaculate has enough spermatozoa to fertilize a female

Describe the difference of Sex-Specific Fetal Hypothalamus in males and females?

15% of pregnancy estrogen is produced in the brain for a male hypothalamus. There is no signal for female.

describe how the male hypothalamus is defeminized

Estradiol turns a “female” into a “male” hypothalamus by minimizing the development of the “surge center”.

Describe testosterones role in defeminization

Secretion of testosterone from the fetal testicle crosses the blood-brain barrier, where it is turned into estradiol.

What is fetoprotein produced by

Parts of the placenta

What is estradiol bound to and what can it not do and why?

Estradiol is bound to Alpha-fetoprotein. It is such a large molecule that it cannot pass the blood brain barrier, so there is no signal in the brain. This develops the surge center.

T or F: Males have a surge center

FALSE

What is Alpha-fetoprotein

Alpha-fetoprotein is a glycoprotein synthesized by the embryonic yolk sac and the fetal liver. It is a fetal blood osmotic regulator and a carrier of fatty acids

Which side is male and which is female?

L - female

R- Male

Describe GnRH levels in the blood of males and females before puberty.

They will sporadic releases with very small spikes. Frequency is erratic and amplitude changes. There are not consistent.

What are the two types of GnRH release

1. Tonic (basal): from the tonic center, with small spikes that are very consistent in amplitude and frequency.

2. Surge Center: Some spike at least once a day, at one given time. Through the estrous cycle (every 20/21 days) you will have this preovulatory surge (high volume production of GnRH).

Describe this image

LH Frequency Before and After Puberty In Females

Describe this image

LH and Estrogen Secretory Patterns In Post-Pubertal Females. LH follows GnRH.

Describe this image.

LH and TESTOSTERONE Secretory Patterns In Post Pubertal Males. Very repetitive. LH will stimulate the cells between the seminiferous tubes (Leydig cells) to release testosterone. This will happen in males until they die.

What hormone is responsible for defeminizing the hypothalamus in the male fetus?

A