ANS 150 Exam 2 (Repro)

Female Reproductive Cycle

Management systems for most animals are based upon what?

To provide spermatozoa for breeding

What is the primary function of male repro systems?

Ovary, Oviduct, Uterus, Cervix, Vagina, Vulva

List the Female Anatomy

Ovary

--> Contains Follicles --> Each Follicle has an "egg" (ovum) --> Receives a plentiful supply of nerves and blood vessels

Follicles

--> Grow in response to gonadotropins (hormones) --> either become atretic (die) or ovulate and release the egg

Corpus Luteum (Corpora Lutea)

--> CL --> created from tissue left after a follicle has ovulated --> produces pregnancy hormones --> primary product = progesterone --> appear red/deep pink/purple bumps on ovary --> present in MATURE animals

Corpus Albicans (Corpora Albicantia)

--> scar tissue left after corpus luteum dies/regresses --> avascular --> appears white on ovary --> present in MATURE animals

Avascular

Non-functioning

Atresia

Follicle Death

Maturation

coming to full development; becoming mature

Oviduct

-->funnel shaped --> has fimbria, which picks up ovulated eggs

Fimbria

picks up ovulated eggs

Ampulla

anterior end of oviduct

Isthmus

Posterior end of oviduct

Oviduct

Where does fertilization and early embryonic development take place in most animals?

Uterus

-->Glandular inner lining thats surrounded by two layers of muscle --> has longitudinal circular layers --> maintains pregnancy! -->releases hormone that regresses the luteal tissue

maintaining pregnancy

What is the main function of the uterus?

Cervix

--> thick, muscular organ --> isolates uterus from external environment --> semen deposition in SOME animals

it serves to isolate the uterus from any harm or bacteria from the external environment during gestation

What is the function of the cervix?

Vagina

-->part of birth canal -->helps protect uterus from bacterial invasion -->semen deposition in MOST animals

Vagina

Where is semen deposition in animals more common?

artificial insemination, selective breeding ex: turkeys, cattle, even dogs

Why would semen deposition occur in the cervix?

Vulva

--> external genitalia -->involved in the recognition of sexual receptivity and also the production of female pheromones

multiple, singular

Animals that have __________ offspring have longer uterine horns than animals that have _________ offspring

Animals that only have one baby at a time. These animals like horses or cows, have high birth weights.

Which animals have a larger uterine body and why?

it includes nerves and blood vessels, and covers the uterus, ovaries and fallopian tubes, which stabilizes the position of the reproductive tract.

What is the purpose of the Broad Ligament?

-->their oviduct does not surround the ovary -->they only ovulate at the ovulation fossa -->grows outside in -->no outward appearance of follicles, CLs, or CAs

What is unique about a mare's reproductive tract?

Testicles, Epididymis, Vas deferens, Secondary sex glands, Penis (urethra), Sheath

List the parts of the male reproductive system.

Testicle

--> series of tubules -->produces spermatozoa (a.k.a sperm) -->produces hormones

testosterone, androgens

List two of the hormones produces in the testicles.

Epididymis (Epididymi)

--> cont. tubule in testicle --> matures sperm/sperm storage --> come in immature, leave mature

"C" Shape

What shape is the epididymis around the testicle?

Vas Deferens

-->muscular tube -->very thin, small diameter -->passage for sperm from epididymis to urethra during ejaculation

epididymis, urethra

Sperms enters the Vas deferens from the _______, and exits into the ________.

Secondary Sex Glands

--> seminal vesicles --> prostate --> bulbourethral glands -->create most of the liquid portion of semen -->specialized composition of each

Seminal Vesicles, Prostate, Bulbourethral Glands

What are the secondary sex glands?

Penis

--> specialized to deposit semen in mate (female repro tract) --> urethra (central canal)

Urethra

common exit for reproductive and urinary systems

Sheath

--> specialized pouch for penis to stay when not being used --> in SOME animals, this is involved in male pheromone production

Gonadotropins

Function: stimulates ovary

Sex steroids/prostaglandins

Function: direct control of reproductive state

Mammotropins

Function: involved in lactation

--> produced in the pituitary glands --> Gonadotropins --> stimulates final growth of follicles --> CAUSES OVULATION --> stimulates corpus luteum (CL)

What are the functions of the Luteinizing hormone (LH)? Where is it produced?

--> produced by the pituitary gland --> Gonadotropins --> stimulates all stages of follicle growth (EARLY PERIODS)

What are the functions of the Follicle stimulating hormone (FSH)? Where is it produced?

--> Produced in Corpus luteum and placenta (SOME ANIMALS) --> Sex Steroid/Prostaglandins --> maintains pregnancy --> stops gonadotropin secretion

What are the functions of Progesterone? Where is it produced?

--> produced by growing follicles, placenta, and embryos --> Sex Steroid/Prostaglandins --> +/- effects on gonadotropins -- stimulates pre-ovulatory boost of gonadotropins --> prepares female for breeding and birth --> mating behaviors

What are the functions of Estrogen? Where is it produced?

Parturition

the process of giving birth

--> produced primarily in the uterus in the repro system -->Sex Steroids/Prostaglandins --> causes luteal regression --> causes uterine contractions

What are the functions of Prostaglandin (F[subscript]2 alpha)? Where is it produced?

--> produced in pituitary --> Mammotropins --> stimulates milk production

What are the functions of Prolactin? Where is it produced?

--> produced by uterus and hypothalamus --> Mammotropins --> stimulates milk excretion

What are the functions of Oxytocin? Where is it produced?

Stages of Reproductive Cycle (specific order)

Puberty Estrous Cycle Pregnancy (Gestation) Lactation Post-partum period (Rebreeding)

ovary, uterus, mammary gland, and the brain

Reproductive cycles involve interaction between...

Puberty

the age at which an animal is capable of adult reproductive function. ovaries and testes are capable of gamete and hormone production before this! LH is last to mature before this!

estrus, libido

Female Puberty is _______ Male Puberty is _________

Estrous Cycle

repeatable sequence of events that results in female becoming sexually receptive. begins with estrus where estrogen is high and progesterone is low.

high estrogen

What causes a preovulatory surge of gonadotropins?

12 to 16 days

How long are progesterone and CL maintained for?

totipotent

having the ability to give rise to cells

--> inner cell mass becomes proper fetus --> cells within inner cell mass differentiate into bones, muscle, nerves, etc.

What happens in the blastocyst?

placental membranes

What does the trophoblast become?

--> rapidly --> last third, most rapid increase --> length is more linear growth, weight it more exponential --> universal

How to fetuses develop? Is this universal?

fetus

Who initiates parturition?

they get a spike in progesterone

What is unique about the horses' parturition process?

High cortisol levels

What are premature births due to?

prolactin --> milk synthesis oxytocin --> milk ejection

What is the difference between prolactin and oxytocin?

It causes a release of LH and FSH. Once it's terminated it results in estrus (not in mares).

What impact does suckling have on LH and FSH? What happens after suckling is terminated?

--> stimulates sperm production --> stimulates testosterone production

What is the purpose of FSH and LH in male endocrinology?

spermatogenesis

sperm production

blastoceole

What is the inside of the blastocyst called?

Unipotent

cells only develop into one type of tissue

8 cell stage

Up to what stage are cells totipotent?