quiz 7 (start exam 3) Flashcards
why are there LH receptors on the theca internal surface
LH responds to and increases cAMP
converts cholesterol into testosterone
why do granulosa cells only have receptors for FSH initially?
because FSH triggers testosterone to convert to estrogen in the aromatase
estrogen is excreted into the blood stream
how long does the pathway continue
until estrogen is at a threshold to induce LH surge
what occurs at selection
granulosa cells acquire LH receptors
FSH goes down but LH receptors are there so it helps drive follicle maturation
cells respond to LH surge
what are the effects of estradiol
increased blood flow
increased mucosal secretion
initiation of uterine gland growth
elevated myometrial tone
lordosis
phonation
physical activity
define ovulation
complicated process which involves the purposeful destruction of a follicle
what can prevent ovulation
protein synthesis
steroid synthesis
prostaglandin synthesis
plasminogen activator synthesis
what do cumulus cells produce
hyaluronic acid and proteins
what does hyaluronic acid and proteins do
cause the cumulus to expand
what does the cumulus expansion allow for
the oocyte to separate from the granulosa cells and allow the complex to float in the atrium
what are the two types of ovulators? give examples
spontaneous- cows, horses
induced- cats, camels
what are the 3 steps of the neuroendocrine reflex
- copulation stimulates sensory nerves in the vagina and cervix
- impulses are relayed to spinal cord
- impulses are relayed to the surge center
describe single vs multiple copulations
single- only works 50% of the time
multiple- higher LH surge
define primordial germ cell
give rise to gametes and migrates to genital ridge and moves into egg nest
define oogonia
undifferentiated germ cells give rise to oocytes
will be surrounded by follicles later
not yet gametes
define primary oocyte
oocyte during growth phase before it completes the first division
makes up majority of life span
define dictyate
developmental arrest during growing phase
grows under gondadotropid independent events
zona pellucida forms
not a primary follice, but a primary oocyte
will move into gonadotropid dependent phase and will be dependent on LH secretion
what become matured during dictyate
nuclear allows nucleus to divide
cytoplasmic- ability of oocyte to be able to develop into embryo
define secondary oocyte
resulting oocyte when meiosis 1 is completed
define polar body
small haploid cell that is formed
pocket of nuclear material that will get absorbed not fertilized
uneven cytokinesis and minimal cytoplasm
if fertilization does not occur, what happens
it will stop at mieosis 2
what part of the oocyte recieves information
granulosa cells
what creates the zona pellucida
the oocyte
how do the granulosa cells and the oocyte communicate
gap junctions
define corona raidiata
granulosa cells surrounding the oocyte and zona pellucida
what triggers cAMP to begin
LH
what do most animals ovulate? what do dogs ovulate?
a 2º oocyte
a 1º oocyte
what makes up a zygote
2º oocyte + sperm
