Repro

Question 1

What are the 3 main classes of hormones?

Answer 1

1. Steroids nucleus
2. proteins/peptides (glycoproteins) membrane
3. eicosanoids

Question 2

What are the diff ways of hormone delivery?

Answer 2

1. Endocrine (EX: estradiol, FSH)
2. Neuroendocrine (EX: GnRH)
3. Paracrine (EX: testosterone from leydig to sertoli)
4. Autocrine (EX: estradiol)
5. Pheromonal/ectohormonal (EX: Bruce effect/ram effect)

Question 3

Describe supraphysiological stimulation.

Answer 3

-internalization of hormone receptors
-hormone is ineffective
EX: prolonged release, high GnRH
>contraceptive in dogs, horses
>suprarelin

Question 4

Describe the source of production of hormones.

Answer 4

1. Pineal = melatonin
2. Hypothalamus = GnRH
3. Pituitary = FSH, LH, prolactin, oxytocin
4. Ovary = estradiol, progesterone, inhibin, testosterone, relaxin, oxytocin
5. Testis = testosterone, inhibin, estradiol
6. Uterus = prostaglandin F2 a
7. Placenta = progesterone, estradiol, hCG, eCG, oxytocin, PGF2a

Question 5

Describe the hormones biochemical structure.

Answer 5

1. Peptide (proteins) = sm. Few amino acids. Easily broken [oxytocin, GnRH, prolactin]
2. Glycoproteins = carbohydrate & protein. Easily broken [FSH, LH, eCG]
3. Steroids = cholesterol. Transpass cell membranes. [estradiol, progesterone, testosterone]
4. Prostaglandins = eicosanoid lipid [PGF2a, PGE2]

Question 6

Describe estradiol.

Answer 6

-made by follicular cells in ovary
-fetoplacental unit
-synthesized from androgens by aromatase
-metabolized in liver
FUNCTION:
F = sexual behavior, LH surge, uterine prep, vag proliferation, role in preg, bone health, immune response
M = testicular health

Question 7

Describe progesterone.

Answer 7

-made by ovary (CL) after ovulation
>prolif & diff of granulosa cells (lg luteal) & theca interna (sm luteal)
-metabolized in liver
FUNCTIONS:
F = maintain preg, sex behavior, mammary gland develop, immune, brain

Question 8

Describe testosterone (androgen).

Answer 8

-made by leydig
-metabolized in liver
FUNCTION:
Masculinization, repro tract develop, spermatogenesis, male sex behavior, anabolic, erythropoietic

Question 9

Describe GnRH.

Answer 9

-made by hypothalamus
-regulated by estrogens
-downregulation
FUNCTION:
F & M = regulate gonadotropins, LH, & FSH

Question 10

Describe LH.

Answer 10

-made by anterior pituitary (adenohypophysis)
-downregulation
FUNCTION:
F = follicular maturation & ovulation
M = spermatogenesis

Question 11

Describe FSH.

Answer 11

-made by anterior pituitary
-downregulation
FUNCTION:
F = follicular development
M = act on sertoli FSH to form secondary spermatocytes

Question 12

Describe prostaglandins.

Answer 12

-PGF2a & PGE2
FUNCTION:
PGF2a = luteolysis of CL & uterine contraction
PGE2 = material recognition of preg in mares

Question 13

Describe oxytocin.

Answer 13

-made by hypothalamus but released by posterior pituitary (neurohypophysis) & CL
-downregulation
FUNCTION:
uterine contraction, milk ejection, maternal recognition of preg, luteolytic release of prostaglandins

Question 14

Describe melatonin.

Answer 14

-made by pineal gland
FUNCTION:
Seasonality, regulates GnRH

Question 15

Describe eCG or PMSG.

Answer 15

-made by endometrial cups
-superovulation
FUNCTION:
Follicles, develop of CL, eCG is FSH & LH-like

Question 16

Describe inhibin.

Answer 16

-made by granulosa & sertoli (dominant follicle)
-neg feedback to anterior
-gonadal glycoproteins
-follicular deviation
FUNCTION:
Regulate FSH release from pituitary gland

Question 17

Describe AMH.

Answer 17

-F = made by granulosa cells of preantral & sm antral follicles
-M = activated by sertoli during fetal develop
FUNCTION:
F = regulate folliculogenesis
M = SOX9 inhibits development of female repro (Müllerian duct)

Question 18

Describe the hypothalamic pituitary gonadal axis.

Answer 18

Question 19

Describe the hypothalamo-pituitary portal system.

Answer 19

-microcirculation connecting the hypothalamus with the anterior pituitary
-GnRH, GHRH, CRH, TRH
-hypothalamic center in females & surge
>tonic = low amp GnRH pulses
>surge = high level of estradiol & high amp GnRH pulse
-regulate levels of estrogens
FUNCTION:
Transport & exchange hormones between the hypothalamus arcuate nucleus & anterior pituitary gland

Question 20

Describe prenatal development.

Answer 20

Sequential
-embryology
-sex diff
-fetal maturation

Question 21

Describe the signaling pathways for embryo development.

Answer 21

-specify cell fate via transcription & development
>contact
>paracrine
>endocrine
>synaptic

Question 22

Describe totipotent.

Answer 22

Cells that give rise to embryo.

Question 23

Describe endoderm, mesoderm, and ectoderm.

Answer 23

Ectoderm=
-repro tract
-cd vag & vestibule
-mammary gland
-penis & clit
-pituitary gland
-hypothalamus
-oral & nasal cavity
-sweat gland
Mesoderm=
-gonads
-uterus, cervix, cr vag
-epididymis, ductus deferens
-accessory sex glands
-urinary system
Endoderm=
-glands

Question 24

What does the trophoblast make?

Answer 24

Placenta

Question 25

Describe embryo VS fetus.

Answer 25

Embryo = no anatomical form that can be recognized Fetus = recognizable species marked by placentation development

Question 26

Describe the reproductive events (trimester).

Answer 26

1st trimester = sex diff (chromosome) 2nd trimester = develop repro tract 3rd trimester = testicular descent

Question 27

Describe sex differentiation (3).

Answer 27

1. Genetic (chromosomal) sex -determined at fertilization *karyotypes: >XX or XY in mammals >ZZ (M) or ZW (F) in birds 2. Gonadal sex -testis determining gene = SRY & SOX9 -ovary determining genes = RSPO1 & WNT 3. Phenotypic sex -tubular & external structures -AMH, testosterone, DHT

Question 28

Describe present SRY gene & absent SRY gene.

Answer 28

1. Presence of SRY = testis determine factor (TDF) -in sex cord of male -medullary sex cord -> sertoli -cortical sex cord -> degen -sex cord -> seminiferous tubules & rete testis -pre sertoli = make AMH 2. Absence of SRY -cortical sex cords -> follicles -medullary sex cords -> degen = female

Question 29

Describe primordial germ cells.

Answer 29

Migrate from outside (yolk sac) into organism through hind gut to undifferentiated gonad at genital ridge.

Question 30

Describe mesonephric duct VS paramesonephric duct.

Answer 30

Mesonephric = wolffian (male) duct >Epididymis/ductus deferens Paramesonephric = mullerian (female) duct *default* >oviduct/uterus/cervix/cranial vag *reproductive system develops at the same time as renal system* [cloaca = rectum]

Question 31

What does the physical sex organ characteristics rely on the presence of?

Answer 31

-TDF & SRY >development of testes & production of testosterone via leydig cells -AMH >degen paramesonephric duct -DHT >development of penis, scrotum, accessory sex glands

Question 32

Describe freemartinism.

Answer 32

-bovine -male (developed first) & female twins (F is infertile) -fusion of placental circulation -AMH transferred from M to F -regress Müllerian ducts -vestigial develop of vag, cervix, uterus, uterine tube -normal vulva & vestibulum derived from urogenital sinus

Question 33

Describe the hypothalamus in M VS F.

Answer 33

Female = -2 areas to secrete GnRH >tonic (M & F) - ARC >surge (F only) - POA -fetal ovaries make estradiol but can’t cross BBB bc its bound to aFP Male = -testosterone crosses BBB & converted to estradiol which defeminizes hypothalamus = eliminating surge

Question 34

Describe fetal maturation in M & F.

Answer 34

Male = testicle descend into scrotum (temp control) >gubernaculum enlarge Female = broad lig & ovaries migrate caudal (except in mares)