Rutgers Animal Reproduction Exam 1

theriogeneology

the branch of veterinary medicine concerned with reproduction, physiology, and pathology of both male and female systems

How does a rabbit test detect human pregnancy?

hCG is detectable in human blood and urine during early pregnancy, hCG induces rabbit ovulation, inject serum, in 2-3 days check ovaries, if ovulation = pregnant

obestrics

branch of veterinary medicine concerned with pregnancy, parturition, and postpartum

The lactocrine hypothesis states that bioactive factors are transported by what means?

delivery of bioactive milk-borne factors into the neonatal circulation through nursing

Barker Hypothesis

the origins of chronic diseases of adult life lie in fetal responses to the intrauterine environment

Name 4 features that make rats great models of reproductive efficiency.

ovulate frequently, relatively short gestation period, high number of pups per litter (10-12), birth triggers ovulation, reaches puberty early (30-35 days)

True or False: XY Inc, Fort Collins, CO have licensed the technology to detect abnormalities in sperm cells.

false, licensed the technology to separate sperm based on DNA content, sex selection

Which sperm has more fluorescence, X or Y?

X sperm

One purpose of MicroSort Inc, Fairfax VA is?

prevention of sex-linked diseases and family planning

True or False: Because rabbits are spontaneous ovulators, they are a perfect candidate to be used as bio-assays for pregnancy detection.

false, rabbits are induced ovulators

How do home pregnancy tests work?

monoclonal antibodies were developed to detect hCG in urine, the antibody complex generates a color reaction, color change shows positive test

Name at least 5 advances in modern reproductive physiology.

cloning, at-home-pregnancy tests, MicroSort to prevent sex-linked disease, artificial insemination, sex selection

Briefly describe asynchronous concurrent lactation and how this supports the lactocrine hypothesis.

Colostrum composition changes depending on the needs of the growing fetus. Supports the hypothesis by showing that milk composition can adapt and guide specific aspects of growth.

What in the mother's milk of rhesus monkeys predicts a more nervous, less confident temperament in both sons and daughters?

glucocorticoids

True or False: MicroRNAs are not found in human, cow, and pig milk.

False, microRNAs are found in human, cow, and pig milk

True or False: An immature gut, soon after birth, can be described as "closed"

True

What connective tissue forms the broad ligament in the female reproductive tract?

Peritoneum

What are the components of the peritoneum and their functions?

mesovarium, mesosalpinx, mesometrium

functions: support, houses blood supply, lymph drainage, nerves

Name the tubular portions of the female reproductive tract in order from the outermost to the innermost.

serosa

musularis

mucosa

submucosa

What are the two types of hormones produced in the ovaries and examples of each?

steroid: androgens, estrogens, progestins

protein: inhibin, relaxin

Name 3 differences between an equine ovary compared to a non-equine ovary.

1. medulla and cortex are reversed (medulla outer, cortex inner)

2. follicles and corpora lutea are located in the interior of the ovary

3. ovulation occurs at the ovulation fossa

The follicle can ovulate anywhere in an equine ovary because surface germinal epithelium completely surrounds the ovary.

False, ovulation occurs at the ovulation fossa

primordial follicle

non-growing pool of follicles

oocyte with a single layer of squamous cells

primary follicle

growing pool of follicles

oocyte with cuboidal epithelium

secondary follicle

2 or more layers of granulosa cells

no antrum

tertiary/antral follicle

multiple avascular granulosa cell layers

fluid filled antrum

What FIRST forms at the site of follicle rupture on the ovary?

corpus hemorragicum

What type of cell does granulosa and theca cells differentiate into?

luteal cells

Name the primary hormone produced by the corpus luteum.

progesterone

Corpus Luteum formation

forms following rupture to prepare the uterus, if fermentation does not occur, the CL stops producing hormone and breaks down forming the corpus albicans

Corpus Albicans

scar-like structure composed of collagen

Atresia

programmed cell death, non-dominant follicles degenerate and die off during menstruation

theca externa

connective tissue of the follicle

theca interna

interior of follicle, source of androgens and blood supply

granulosa cells

majority of cells surrounding an oocyte, produce estrogens and progestins, avascular

polycystic ovarian syndrome

PCOS

multiple small cysts (unruptured follicles)

high androgens

infertility

insulin resistance

In one theory regarding the cause of ovarian cancer, the wound and repair of what cell type is thought to trigger mutation?

ovarian surface epithelium (OSE)

Which hormone(s) action(s) on the ovarian surface epithelium (OSE) is thought to induce tumor formation?

gonadotropin stimulation - release FSH and LH

Ovarian Reserve Index (ORI)

test determining the number of eggs a woman has left in her ovary

The blood levels of which three hormones are measured with the Ovarian Reserve Index (ORI)?

inhibin B, anti-mullerian hormone (AMH), and follicle stimulating hormone (FSH)

Antral Follicle Count (AFC)

ideal # is 15-20 per two ovaries

AFC below 10 is considered low

Polycystic Ovary

high AFC and ovarian volume

35+ is considered high

What two cells "luteinize" or differentiate to form the corpus luteum?

theca interna and granulosa cells

What is 25-55% of early embryonic loss due to?

corpus luteum insufficiency

functions of the corpus luteum

secretes progesterone

maintains pregnancy

regulates the cycle

How is the avian reproductive system different from the mammalian reproductive system?

only left ovary and oviduct function, produce a shell membrane, have yolk (no antrum or follicular fluid), have a cloaca

Where is the site of fertilization by sperm in an avian ovum?

germinal disk (IN OVUM)

Where does fertilization occur in the avian tract?

infundibulum (IN TRACT)

From the site of fertilization in birds, trace the path of the egg in the avian reproductive tract.

infundibulum → magnum → isthmus → shell gland or uterus → vagina → cloaca

Ovum

mammalian oocyte equivalent

called the yolk

consists of a germinal disk and vitelline membrane

What is another name for the shell gland in the avian reproductive tract?

uterus

What are the parts of the mammalian oviduct?

infundibulum, ampulla, isthmus

What structural aspect of the infundibulum assists in the transport of the oocyte?

fimbriae

oviduct functions

transport of gametes and the embryo

secretions to maintain oocyte, sperm, and fertilized egg

Where is the site of fertilization in the mammalian oviduct?

ampulla

duplex uterus type 1

2 cervices

2 separate uterine horns

2 vaginas

no uterine body

ex. marsupials

duplex uterus type 2

2 cervices

2 uterine horns

1 vagina

ex. rabbits

biocornuate uterus

2 uterine horns

small uterine body

1 cervix

ex. mare and cow

simple uterus

no uterine horns

large uterine body

exp. humans

uterine functions

sperm transport

regulation of CL function

implantation/placentation

parturition

Uterine signal that causes CL regression

prostaglandin

cow, ewe cervix

annular rings of cartilage

sow cervix

interdigitated rings

boar cervix

penile adaptation called corkscrew

mare cervix

longitudinal folds

cervix in early pregnancy

thick cervical mucous

barrier to sperm transport

prevents uterine infection

cervix at time of birth

cervical mucous thins

cervical plug liquifies

cervical canal opens

What controls the viscosity of the cervical mucous?

hormones

high serum estradiol = watery mucous

high progesterone = thick mucous

vagina structure - cranial

near cervix

columnar epithelium

highly secretory

vagina structure - caudal

vestibule

stratified squamous epithelium

vagina functions

copulatory organ

excretory duct

birth canal

vulva

external part of the tract

labia major and minor

outer and inner folds of skin, contains fat and smooth muscle

clitoris

homolog of the penis

erectile tissue, sensory nerves, epithelium

erect during estrus

sensory function

Describe the equine placenta.

diffuse

epitheliochordial

microtyledons

Epitheliochorial

3 fetal layers

3 maternal layers

Microtyledons

thousands of microscopic structures on the placental surface

site of maternal-fetal interaction

increase placental surface area

equine gestation length

331-350, 11 months

What is the source of progesterone in the first half of mare gestation?

corpus luteum

What is the source of progesterone in the second half of mare gestation?

feto-placental unit

Endometrial Cups

diffusion

transitory day 35-60

produce eCG

Equine Chorionic Pregnancies (eCG)

unique to equine pregnancies

form from trophoblast tissue and are embedded in the endometrium

eCG function

like LH, luteinizes follicular waves to create secondary CL during pregnancy

What is Premarin?

hormone replacement therapy to relieve symptoms of menopause

Premarin use

source of equine estrone, equilin, and equilenin

found to have associations with coronary heart disease and breast cancer when used with progestin

placental insufficiency consequences

stillborn births, premature delivery

premature birth conditions

respiratory hypoxia, neurological issues, postpartum foal death

Mare reproductive loss syndrome (MRLS)

issue in KY and OH

over 5000 cases of early and late-term abortion

caused massive financial loss

Three functions of relaxin

relaxes reproductive smooth muscle

remodels connective tissue

promotes growth

What is the primary source of relaxin in horses?

placenta

What is Oligohydrallantois?

reduced fetal fluid production

What is the disorder in horses characterized by an excess of fetal fluid production?

hydrops

True or false: A mare with a pituitary tumor was seen to have a prolonged gestation.

true, other issues too like placental separation

True or false: A study showed a decreased amount of circulating relaxin during gestation in mares with twins

false, decreased relaxin

What fungus, which infects fescue pastures, and toxin it produces is linked to reproductive problems in horses?

fungus - ergovaline

endophyte infected fescue

What health problems are associated with fescue toxicosis?

prolonged gestation, dystocia, placental operation, placental thickening, decreased blood flow, agalactia

How does ergovaline exposure lead to fescue toxicosis?

Ergovaline is an ergot alkaloid that acts as an agonist at dopamine receptors, particularly D2 dopamine receptors. When these receptors are stimulated by ergovaline, it inhibits the release of prolactin, a hormone critical for several reproductive functions, especially in late pregnancy.

Inhibition of prolactin affects the development of the mammary glands, leading to agalactia.

Explain how an enzyme-linked immunoassay (ELISA) works to detect a protein hormone, like relaxin.

1. 2 antibodies needed, one that recognizes the hormone of interest and one linked to an enzyme detection system

2. hormone AB is bound to a solid support

3. hormone of interest in blood binds to AB and forms a complex

4. the enzyme AB binds to the hormone complex

5. a substrate is added and a color reaction occurs

What does the spermatic cord suspend

suspend the testes in the scrotum

Explain how the pampiniform plexus regulates the testes temperature.

warm arterial blood is cooled when it enters the PPP, the heat is transferred to the spermatic vein which returns cool blood to the body