quiz 5 Flashcards
(40 cards)
define episomic hormone release
occurs when there is stimulation/positive feedback
common with hormones under the nervous control
high spikes of release
ex: GnRH surge to respond to estradiol
define basal hormone release
background hormone release pattern
small blips of hormone release every 2-4 hours
ex: GnRH release from tonic center
define sustained hormone release
hormone increases and remains high
steady amount of hormones
can remain elevated for days/weeks
ex: steroid hormones
what’re the steps of the female negative feedback loop
- GnRH is released from tonic center of the hypothalamus at the tonic level
- tonic lh and fsh result in follicular growth on the ovary
- follicles will grow and produce estradiol and inhibin
- one follicle reaches the point where it makes high estradiol which becomes the dominant follicle
- primarily the LH and FSH surge due to high GnRH release
- ovulation is induced
- ovulated follicle will lutenize and become a CL which produces progesterone
- high progesterone will feedback negatively and inhibit GnRH
what are the steps of the male negative feedback loop
- tonic levels of GnRH releases from the hypothalamus
- tonic release of FSH and LH for anterior pituitary
3a. FSH signals Sertoli cells in semineferous tubules; promotes spermatogenesis
4a. sertoli cells release inhibin and decreases FSH
5a. produces ABP (androgen binding protein)
3b. LH signals leydig cells to produce testosterone
4b. testosterone binds ABP which makes it more lipophobic and keeps testosterone in lumen where spermatozoa are present and helps with sperm maturation
5b. testosterone has a negative feedback loop on the hypothalamus to decrease tonic FSH and LH
what are the 3 sections of sperm
head, midpiece, tail
what are the parts of the head
nucleus, acrosome, and post nuclear cap
what are the parts of the tail
mid piece, principle piece, and terminal piece
describe the head
contains nuclear material
describe the midpiece
contains mitochondria in a spiral fashion around the flagellum and ends at the annulus
describe the principle piece
the tail
has no mitochondria
describe the sperm of bulls, rams, boars, and stallions
oval and flat; tail length varies
describe human sperm
rounded head and 3-dimensional
describe rodent sperm
hook-shaped head
describe bird sperm
long and narrow
what is the entire sperm head covered by
the plasma membrane
define acrosome
membrane bound lysosome necessary for fertilization
define apical ridge
bulging area at the proximal region of nuclear head
define equatorial segment
distal boundary of the acrosome
define postnuclear cap
portion below the equatorial segment
describe the sperm head from exterior to interior
plasma membrane, outer acrosomal membrane, acrosomal contents, inner acromosal membrane, nuclear membrane, nucleus
describe the sperm head from the anterior portion to the posterior portion
apical segment, principle segment, equatorial segment, postacromsomal segment
define acrosin
drills through the zone pellucida
define hyaluronidase
dissolves hyaluronic acid in cumulus
