Test 2 Questions Flashcards
Indifferent gonad
Primordial germ cell migration (Proliferating as well)
Y Chromosome has SRY (Development of testis)
SRY is a _____ cell.
Somatic cell NOT germ cell
Testosterone
From Leydig Cell -> wolferian ducts
AMH
From Sertoli Cell -> Regression of mullerian ducts
Estradiol & DHT: Function?
Masculinize the male brain
DHT: More potent androgen than testosterone
can not turn into estradiones
Testosterone converted to E2 by…
Aromatase
Testosterone converted to DHT by…
5 alpha-reductase
a-fetoprotein function?
Prevents estradiol from crossing into the brain and masculinizing it
3 types of cysts
- ) Follicular Cyst
- ) Lutenized Follicular Cyst
- ) Cystic Corpus Luteum
What causes a cyst?
Disfunction of H/P/G axis
Physical signs of a cyst
- Nymphomania
- Lack of muscle tone
- Excessive discharge
Treatment if cysts present:
- Rupture with fingers
- GnRH -> Release of LH
- hCG -> LH-like
Would you rather give GnRH or hCG?
- GnRH because it is well conserved and natural.
- hCG is derived from humans and can cause problems/not work
Cystic Ovarian Disease
Dairy: Early Lactation
Genetics/Heritability
Nutrition/Season
T/F A cow can get pregnant when a cyst is present.
False
Follicular Cyst
Follicle that keeps growing and doesn’t ovulate or lutenize
Lutenized Follicular Cyst
Thin layer of luteal tissue
Estrogenic VS. Non-Estrogenic
Late cysts are usually non-estrogenic
Cyst causes hormonal changes. What are they? (4)
- Increase in angiotensin: stimulates blood vessels
- Increase in EP4: Receptor to Prostaglandin B
- Decrease in FBF -> P4 (cellular differentiation)
- Decrease in indian hedgehog protein precursor (Cell Proliferation)
Hedgehog Family (3)
Indian Hedgehog
Conic Hedgehog
Desert Hedgehog
Follicle innervation
Theca cells
B- Adrenergic Receptors
non-Adrenaline
In cysts, what increases? What decreases?
Increase in Cortisol (stress)
Decrease in Reactive Oxygen
Humans PCOS
- ) Hyper-androgen
- ) Oligo or anovulation: ovulation disfunction
- ) Polycystic ovarians
Only need 2 of the 3 symptoms
What is Spinnbarkeit?
- Influenced by estradiol
- Elasticity of cervical mucus
- More mucus produced
What is Metritis?
- Inflammation of uterus
- Inflammation of endometrium including glandular and myometrium.
What is Endometritis?
-Inflammation of endometrium and glandular tissue only
What are the 3 causes of metritis?
- ) Systematic infection could target uterus
- ) Venereal (Bull with STTD can transmit)
- ) **Post-Calving
Endometriosis
-Where endometrial tissue is growing outside the uterus (could be abdominal cavity, ovary, oviduct, etc. - Painful Everything)
What is nymphomania?
Constant display of estrus
When is metritis most often observed?
Most often observed post-calving (40-45 day around involution)
What induces cysts?
ACTH
What can affect follicular growth?
Cysts on ovaries
What triggers parturition?
Cortisol
What does PGF2a do? What two organs does it affect?
Regresses CL, induces contractions
-Affects ovary and uterus
What does OT do?
Contractions, OT-R increased by E2, neural feedback
What does P4 do? Produced by?
Relaxes myometrium = NO parturition
-Produced by CL and placenta
What does E2 do?
- Placental
- Affects OT-R, PGF2a-R
What is the enzyme for final conversion of androgens to estrogens?
Aromatase
More contractions =
More feedback
High-energy/gain =
Earlier puberty
Low-energy/gain =
Later puberty
More invasive means…
More chance that fetal and maternal blood can mix
In the male, the Wolfian ducts develop into testis. T or F
False - Gonads
Mullerian ducts develop into…
Female parts
In the male, SF1 induces/activates the testis determining factor, Sry. T or F
False - SOX-9 induces Sry
In the male, fetal leydig cells differentiate into adult leydig cells. T or F
False
A male with an extra Y chromosome is expected to be of normal fertility. T or F
True
A female with an extra X chromosome is expected to be of normal fertility. T or F
True
Describe how/why the fetal female brain is not masculinized?
The female brain is not masculinized because alpha-fetoprotein acts as a barrier and does not let E2 get into brain.
Without estradiol in the brain, the female can develop female-like traits and characteristics since estradiol in the brain causes masculinization.
During seasonal anestrus in the ewe, estradiol will decrease pulse amplitude of LH released by the anterior pituitary. T or F
False - During estrus this occurs
During seasonal anestrus in the ewe, P4 will decrease the pulse frequency of LH released by the anterior pituitary. T or F
True
The secretion of serotonin by pineal gland is the primary regulator of seasonal anestrus in the ewe. T or F
False - Secretion of melatonin
Puberty in the heifer calf is expected to be delayed if that animal is reared on a low plane of nutrition. T or F
True - low energy diet = later puberty
During sexual differentiation in the male, describe hormonal signals involved in the development and regression of the Wolffian an Mullerian ducts.
Type - Hormone - Cell type
Wolffian - Testosterone - Leydig cells
Mullerian - Anti-mullerian hormone - Sertoli cells
Describe how/and by what the fetal male brain is masculinized.
Masculinized by estradiol reaching the brain. Specifically, Male - testis –> Testosterone –> Brain –> 5-alpha-reductase goes to DHT –> Aromatase goes to E2
Female - ovary –> Estradiol –> alpha-fetoprotein binds to E2 and stops it from getting into the brain
The gonadostat hypothesis equates the changes that occur in feedback at puberty to a resetting of the hypothalamic/pituitary/gonadal axis “thermostat”. T or F
True
Name the 3 defining criteria of polycystic ovarian syndrome (PCOS) in women. Indicate how many of these criteria must be met to be diagnosed as having PCOS.
- ) Anovulation/ Oligo-ovulation
- ) Androgenemia
- ) Polycystic ovaries
*Only 2 of 3 need to be present to have PCOS
A heifer has a large, estrogenic follicular cyst. If I compared the relative expression of mRNA for Angiotensin in tissue collected from this cyst versus estrogenic dominant follice, would I expect to see a difference?
Yes
A heifer has a large, estrogenic follicular cyst . If I compared the relative expression of mRNA hedgehog protein precursor in tissue collected from this cyst versus an estrogenic dominant follicle. Would I expect to see a difference?
Yes
A heifer has a large, estrogenic follicular cyst. Would I expect to see differences in steroidogenesis among small follicles (3-5mm in diameter) that were present on the same ovary of this animal?
Yes. E2 and T4 would increase and there would be no change in P4.
A heifer has a large, estrogenic follicular cyst. Would I expect to see differences in steroidogenesis among large follicles (10-15mm in diameter) that were present on the same ovary of this animal?
No. There is no changes in P4, E2 or T4. They remain constant.
Detecting heat in... Cows? Pigs? Humans? Sheep?
Cows - mount each other
Pigs - back pressure test
Humans/Primates - sexual activity frequency increases around time of fertility (male driven)
Sheep - Flehmen’s response displayed by males. Method used to detect pheremones. Only stand still when in heat (use vasectomized male to detect)
With Flehmen response, what is the chemoreceptor?
Vomeronasal organ
What is lordosis?
Sexual posture, arching of the back
Will the female seek the male if he cannot get to her and she is in estrus?
YES
Will the female seek the male if he cannot get to her and is castrated and she is in estrus?
No
Abortion in cattle causes bacterial problems:
1.) Brucellosis: aborts 6-9 months into pregnancy
2.) Leptospirosis:
Host-adapted: Cow –> Cow
Non-hostadpated: Other species –> Cow
Abortion in cattle causes protozoal problems:
Trichomoniasis - highly contagious
Protozoal colonize in the repro tract
Bulls (penis/prepuce) carry and pass to Cows (vagina)
Even if infection is low, it can be spread easily.
Clears itself up after 6mo of being sexually abstinant
Abortion in cattle causes viral problems:
- ) Bovine Viral Diarrhea (BVD) causes infertility (breeding season - including early embryonic death) and abortion (pregnancy)
- Modified live vaccine
2.) Infectious Bovine Rhinotrachitis (Red nose) - Herpes
Length of spermatic cycle in bulls
2 months
