Exam 4- Male Reproductive Physiology II Flashcards
where is sperm stored?
tail of the epididymis
what happens to sperm in the epididymis?
matures and gains ability to become motile
what enters the epididymal duct?
sperm and rete fluid
what produces the rhythmic contractions in the epididymis?
smooth muscle
how can sperm end up in urine?
escapes out of tail of epididymis into ductus deferens to pelvic urethra
where is sperm concentrated?
head of epididymis and continues throughout
what do the functions in the epididymis depend on (with sperm)?
testosterone
sperm must be both ___________________, yet _____________________
prepared to be motile
repressed from being motile
what is necessary for sperm motility?
cyclic AMP
what in the epididymis could help prevent motility?
lower calcium levels
what is capacitation?
changes in sperm
can only truly occur in female system
what happens in capacitation?
changes in plasma membrane that will allow fusion of sperm with oocyte and capacitation
change in position cytoplasmic droplet
true/false: both frequent and infrequent ejaculation can affect sperm quality
true
from which region of the epididymis are sperm ejaculated?
tail
what happens when very frequent ejaculations occur?
sperm numbers reduced
immature sperm released
what happens when there are very infrequent ejaculations?
quality of sperm generally poor
what are the requirements for erection?
elevated arterial inflow
dilations of sinusoids in blood sinuses
restricted venous outflow
elevated intrapenile pressure
relaxation retractor penis muscle
what is innervation doing in a non-erect penis?
sympathetic
vasoconstriction
smooth muscle tone within walls of blood sinuses
what is innervation doing in an erect penis?
more parasympathetic than sympathetic
nonadrenergic, noncholinergic (NANC)
release nitric oxide
blood vessels/sinuses relax
engorgement
what is required for an erection- emission?
sensory stimuli
hypothalamus
oxytocin
movement sperm
what does oxytocin do during emission and what releases it?
posterior pituitary
smooth muscle contraction
what do smooth muscle contractions do in emission?
in epididymis and ductus deferens
move sperm into ductus deferens and pelvic urethra: positioned for ejaculation
what secretions help form the seminal plasma?
from accessory sexual glands
from tail of epididymis
what is present in seminal plasma?
fructose
ovulation induction factor (OIF)
female immune tolerance substances
+/- copulation plug
fluid for volume (important in pig)
does parasympathetic or sympathetic stimulation control ejaculation?
sympathetic
what are muscle contractions in ejaculation initiated by?
sensory stimulation of glans (intromission)
pudendal nerve transmits
what are the target muscles in ejaculation?
urethralis
ischiocavernosus
bulbospongiosus
where does phagocytosis of sperm occur?
vagina, cervix, uterus
neutrophils enter uterus post-mating
can phagocytosis of sperm in the female tract do damage?
yes- inflammatory response- to uterine endometrium
what happens to “sequestered” sperm?
capacitation
released gradually
isthmus of oviduct
viability promoted
what is transport of sperm in the female tract under the influence of?
estradiol
what is capacitation?
membrane of sperm changes so that acrosome reaction can take place
motility pattern changes: hyper-activated motility: spiral trajectory
what does the acrosome reaction enable the sperm to do?
penetrate the zona pellucida
fuse with oocyte membrane
can acrosomal damage be reveresed?
no
what does the plasma membrane of the oocyte fuse with?
fusion proteins on equatorial segment of sperm
what does alpha-fetoprotein do?
prevents most of estradiol from crossing blood-brain barrier in CNS
what is testosterone converted into in the male fetal brain?
estradiol by aromatase
what is desensitization?
when a cell is exposed to LH for too long and no longer responds
is sperm concentrated in the rete of the testis?
no
what is restricted venous outflow in an erect penis aided by?
smooth muscle contractions
arterial engorgement
what nerve stimulates the urethralis, ischiocavernosus, and bulbospongiosus muscles during ejaculation?
somatic nerve- pudendal
in what species is the phagocytosis of sperm and the ensuing inflammatory response especially important?
horses
what is the initiation of the acrosome reaction?
sperm binding with zona
what does the acrosome reaction involve?
fusion of plasma membrane of sperm with outer acrosomal membrane of sperm
creates vesicles/pores
enzymes pass through pores
where is sperm modified during the acrosome reaction?
equatorial segment
what is acrosin?
an enzyme released from the acrosome reaction
hydrolyzes zona proteins
where are pheromones produced?
urine
feces
vaginal secretions
saliva
specific scent glands
