2: BSE in M - general and canine Flashcards
(120 cards)
where do testes originate before descent?
what do they pass through?
where do they end?
abdomen
thru inguinal ring - inguinal canal and superficial inguinal ring to rest in scrotum
how do testes descend?
what structure is key and how does it work?
gubernaculum mediates descent
it shortens and swells to pull testes into and through canal
shrinks and remnant is left in srcotum
what structure does gubernaculum become in adult M?
lig of tail of epididymis
descent of testes in species: ca fe eq bo, ov, cap, por
ca: 14 days old - 6 mos
fe: at birth
eq: 10 days old - 9 mos old
bo/ov/cap/por: birth - rest are culled so latest descent not known
what is required for puberty to occur?
- beh to allow successful courtship, intromisssion and copulation [erection and protrusion]
- ejaculate contains min # spermatozoa req’d to achieve preg [do not have to be high quality to be succesful]
age of puberty depends on what factors?
- season of birth (if seasonal breeder)
- breed
- size of litter
- BCS / plane of nutrition
- housing and stocking density
why does poor BCS inhibit puberty?
suppresses LH levels so dec stim of leydig cells so dec testosterone is produced
age at puberty: ca fe eq bo ov cap por llama/alpaca
ca: 9 mo - 5-12
fe: 9 mo - 8-10
eq: 12 mos - 10-24 or 2nd spring of his life
bo: 11 mos - 7-18
ov: 7 mos - 6-9
cap: 5 mos - 3-8
por: 7 mos - 5-8
llama/alpaca - 2-3 yrs
endocrinology of puberty:
in young animals, what sex has surge center?
in adults?
young: M and FM
adult: FM
implications of surge center or lack of surge center in each sex adult?
M - no surge - frequent pulses of LH throughout day - subsequent pulses of Testosterone (T)
FM - surge center - surge of LH occurs during estrus
loc of surge center?
hypothalamus (hypo)
hormone sec by hypo?
GnRH
GnRH stim what brain structure? what hormones are produced?
ant pit gland
FSH and LH
what does FSH stim in M?
sertoli cells to sec T
what does LH stim in M?
Leydig cells to prod spermatazoa
composition of testes?
seminiferous epithelium and interstitium
what is present in seminiferous epithelium?
germinal epithelium
sertoli cells
what do sertoli cells prod?
inhibin
e2
dihydrotestosterone (DHT)
what is present in interstitium of testes?
leydig cells
what do leydig cells prod?
T
estron sulfate
what species seasonal breeders?
long day?
short day?
what effects on reproductive fxn during off season?
feline - long day - dec sperm count in winter
ov - short day - dec libido, dec scrotal circumferenct, dec semen quality in off season
cap - short day - dec libido, buck odor, scrotal circumference, semen quality in off season
equine - long day - dec sperm count during winter
general terms: what does M need in order to successfully breed?
- coordination and control [hypo, pit]
- prod of gametes [seminiferous tubules of testes, spermatic cord, scrotum]
- storage of gametes [epididymis]
- prepare gametes for FM tract [accessory sex glands]
- deliver gametes to FM tract [ductus deferens, urethra, penis/prepuce]
- support [musculoskeletal, ocular, GIT]
fxn of testes?
- sperm prod in semiferious tubules
- endo gland in interstitum
where in testes does sperm prod occur?
sertoli cells - adluminal compartment specifically