Semen Transport and Elimination Flashcards
Finishing the cycle
final alterations and packaging occurs in accessory sex glands and delivery system (penis)
semen
bodily fluid released during ejaculation
secreted by the testes (spermatozoa+fluid) and other sexual organs (seminal plasma)
Organs participating in formation of semen
testicle- sperm cell formation and small amounts of fluid
epididymis= sperm maturation and epididymal fluids
accessory sex glands= nutrients and fluids
semen- gametes and seminal plasma
epididymal vs. ejaculated sperm
ejaculated sperm has surface molecules- proteins and carbs and along with epididymal sperm and seminal plasma is ejaculated within female tract
Anatomy
Ampulla, vesicular gland, prostate and bulbourethral glands
if cut open have the colliculus seminal surrounded by urethral wall and the ejaculatory and vesicular ducts along the outside
Penis drop
parasympathetic
erection of the shaft and glans penis, release of nitric oxide and pre-ejaculatory secretions
flacid vs. erect penis
cavernosal artery full in erect
tunica albuginea thicker in flacid
emission
release of sperm and accessory sex gland fluid into pelvic urethra
ejaculation
forceful expulsion of the combined fluids from the urethra
Emission
sympathetic, thoracic-lumbar reflex
caudal mesenteric ganglion*
contractions of smooth muscle
Ejaculation
sympathetic: a-adrenergic
sacral reflex
contractions of the ischiocavernosus, bulbospongiosus, urethras, and other striated muscles
Detumescence
sacral symp.
increased smooth muscle tone in corpus cavernosum and spongiosum
contraction of the retractor penis muscle
sperm in the female report tract
semen deposition- glans penis and urethral process
ruminants
1 jet (sperm rich fraction)
equid
5-7 jets (~ 3 jets of sperm rich fraction and gell fraction)
swine
gell fraction, sperm rich fraction and gel fraction
canine
sperm poor fraction, sperm rich fraction and prostatic fraction
semen deposition
vagina- bull, ram, man, tom cat, stud dog
cervix- boar
uterus- camelids, stallion, stud dog, and boar
sperm survival
billions of sperm
sperm motility= progressively motile, non-progressively motile and immotile sperm
immediate transfer (out of female tract)
retrograde loss, phagocytosis, and entrance into cervix/uterus
immediate loss
species dependent
retrograde loss= 60% in cattle
cervical or vaginal plug
Cervix
privileged pathways (selective barrier)- sialomucin-thin sulfomucin- thick
removal of non-motile sperm
removal of some abnormalities
reservoir in some species, sperm motility
Sperm in the uterus
uterine contractility- propel semen cranially and caudally- transport and elimination
oxytocin- mating and social interaction
PGF2a- seminal plasma
estrogen-seminal plasma
capacitation
sperm membrane changes begin, occurs once in female tract
outside protein coat is lost
sperm elimination
breeding induced endometritis- PGF*
sperm induce inflammation and an influx of polymorphonuclear neutrophils (PMN) into the uterine lumen
mechanisms of sperm elimination
phagocytosis
activated PMNs release PGF2a
PGF2a causes myometrial contractions
role of seminal plasma
decreased duration of inflammatory response, protects live sperm from PMN binding
promotes PMN binding with dead sperm
sperm in the oviduct
uterotubal junction- sperm barrier
isthmus- reservoir
ampulla-fertilization
infundibulum- guides oocytes (fimbriae)
storage
oviductal isthmus= storage, sperm selection (high fertile sperm), prolongs viability and prevents completion of capacitation because needs to occur in female
assisted breeding techniques
conditions may be altered- no social interaction between male and female
conditions may be altered- sperm elimination
cryopreservation- may interfere with binding to oviduct
removal of seminal plasma= loss of protective effect and increased duration of breeding induced endometritis
assisted breeding techniques- alter semen deposition
deposit semen in uterus
reduce breeding dose
reduce number of inseminations
