Physiology Exam 2 - Reproduction

What has the main function of gametogenesis and steroidogenesis?

Gonads

What is the control of reproduction maintained by?

Feedback mechanisms

What does the transport of hormones depend on?

Water solubility and if the hormone is protein bound

How can hormones be removed?

Metabolic destruction, binding with tissues, hepatic excretion, renal excretion

What can be tested for to determine if an equid is pregnant?

Estrogen in the urine

What is the master organ of repo?

Hypothalamus

What hormone does the hypothalamus release?

GnRH

What does the hypothalamus regulate?

Body them, endocrine systems, appetite, sex behavo, fear/rage centers

What type of hormone is GnRH?

Peptide

What does GnRH cause the reales of?

Pituitary hormones

What is essential for stimulation of gonadal activity and are used to regulate reproductive function?

Gonadotropins

What are the two main goniodoridids that the anterior pituitary release?

 LH and FSH

T/F we have products that can replace/replicate the sex hormone response

TRUE

What are the two centers of the hypothalamus?

Tonic center and surge center

What center is like a leaky facet?

Tonic center

What center is like a fire hose?

Surge center

Where is oxytocin released?

Posterior pituitary

Gonads of males?

Testes

Gonads of females?

Ovaries

What are the gametes produced in females?

Ova

What are the gametes produces in males?

Sperm

What are some of the steroids produced by the gonads?

Estrogen , progesterone, testosterone, etc

What is the primary male hormone?

Testosterone

What does LH cause Leydig cells to secrete?

Testosterone

What does FSH stimulates the Sertoli cells to produce?

Estrogen from testosterone

What are the two cells in the testicles?

 Leydig and Sertoli

What is responsible for distinguishing the phenotypic characteristics of males?

Testosterone

What region on what chromone casques the genital ridge to develop to produce testosterone?

SRY on y chromosomes

What determines if a females is females?

The lack if Y chromones (XX)

What are the two primary hormones of the ovaries?

Estrogen and progesterone

What acts on the follicle to produce estrogen and stimulate follicular development?

FSH

What acts on the ovary to stimulate ovulation and CL function?

LH

What hormone can be given to trigger ovulation?

LH

What suppresses FISH?

inhibin

What produces p4 (progesterone)?

CL

What causes a negative feedback prior to ovulation?

Inhibin

What causes a negative feedback post-ovulation?

Progesterone

What causes virilizing effects in males?

Testosterone

T/F testosterone is a negative feedback loop

TRUE

What three methods are being researched for relacing castration?

Target hypothalamus, target testis, immunological

What is the acquisition of reproductive competence?

puberty

What hormone must be secreted at the appropriate frequency causes puberty by stimulating gonadotropin release by the pituitary?

GnRH

What center is the male missing in the hypothalmus?

Surge center

What is the only center in the male haypothalamus?

tonic center

What gender is the hypothalamus inherently?

female

What hormone defeminization the hypothalamus and eliminates GnRH surge center in males?

Testosterone

What are the three definitions of mature in females?

first heat, first ovulation, age at which pregnancy can be maintained without deleterious effects

What definition of puberty in females is easiest to detect?

age of first heat

What definition of puberty in females is difficult to dectect?

age at first ovulation

What definition of puberty in females is most practical?

age at which pregnancy can be maintained without deleterious effects

What percent of adult body weight is a female able to maintain pregancy without deleterious effects?

65%

What definition of puberty in males starts at the earliest age?

expression of behavioral traits

What definition of puberty in males starts at the oldest age and is most valid for our purposes?

When ejactulate contains a threshold number of sperm

What 4 things can influence when an animal reaches puberty?

fat, body composition, evenironment, genetics

What from the sire can effect when his offspring will have an early puberty?

scrotal circumference size

What are 4 environmental and social cues?

Season of birth, photoperiod, presence of opposite sex, and population density

What can be a major hold up for puberty?

Failure of hypothalamus (no GNRH)

What hypothalamic center releases GnRH at a low frequency constantly?

tonic center

What hypothalamic center releases GnRH in large amounts?

Surge center

T/F the GnRH from the Tonic center causes ovulation

FALSE

What causes the pubertal transition to start in females?

loss of negative feedback against E2

What causes the pubertal transition to start in males?

oss of negative feedback against T

How quickly is the negative feedback lost in pubertal transition?

slowly

What does the loss of negative feedback lead to higher levels of what hormones in females?

GnRH which leads to more E2

What does the loss of negative feedback lead to higher levels of what hormones in males?

GnRH which leads to more FSH/LH

What triggers the surge center?

E2

What does the large quantities of GnrH releases from the surge center in females cause?

ovulation

When do bovines hit puberty?

11 months

When do equines hit puberty?

14 months

When do ovine hit puberty?

7 months

When do porcine hit puberty?

7 months

When do canines hit puberty?

9 months (up to 24 months)

When do felines hit puberty?

9 months (can be as short as 4 months)

What is the period of sexual receptivity in females? NOTE: it is a noun

Estrus

What adjective is used to describe the things around estrus; ie _____ cycle or _____ behavior ?

estrosus

What begins with estrus and ends at the onset of subsequent estrus?

estrous cycle

What can cause interruptions in cyclicity (aka anestrus)?

Pregnancy, nursing, changes in photoperiod, inadequate nutrition, stress, pathology

T/F cyclicity starts → breeding occurs → pregnancy → parturition → uterine involution → lactation → resumption of cyclicity (repeat)

TRUE

When are breeding seasons?

when environment will allow for best survival of young

What are the three types of cyclicity?

polyestrous, seasonally polyestrous, and monoestrous

What animals are polyestrus?

cow, swine, and rodents

What animals are short day breeders (seasonally polyestrous)?

Sheep and goats

What animals are long day breeders (seasonally polyestrous)?

horses and cats

What animals are monoestrus?

dog

What type of cyclicity has multiple periods of estrus each year?

polyestrus

What type of cyclicity depends on photoperiod?

seasonally polyestrous

What type of cyclicity is one period of estrus each year?

monoestrous

What are the two major phases of the estrous cycle?

follilcar phase and luteal phase

What is the period from CL regression ot ovulation?

follicular phase

What is the period from ovulation to CL regression?

Luteal phase

What is the dominant structure of the follicular phase?

growing follicle

What is the dominant structure of the luteal phase?

corpus luteum

What is the dominant hormone of the follicular phase?

estradiol

What is the dominant hormone of the luteal phase?

progesterone

What is the purposes of female behaviors?

attractiveness, proceptivity, receptivity

What animals show signs of estrus?

cows, mares, and sows