T3: Embryonic Development Flashcards
T/F: once sperm are in the female tract, all the sperm from that ejaculate are capacitated at the same time
false
what is true about capacitation
-It is defined as the set of changes in the sperm plasma membrane that enables a cell to acquire fertilizing potential and undergo the acrosome reaction
-acrosome is altered and is not reversible
The purpose of the acrosome reaction is to:
Enable the sperm to penetrate the zona pellucida and Modify the equatorial segment so that it can later fuse with the plasma membrane of the oocyte
The 9+9+2 arrangement in the sperm tail describes the:
axoneme
vasodiltion, inhibit vasoconstriction, relax retractor penis muscle
erection
contraction of cauda epididymis and vas deferens/ release of accessory gland fluid
emission
erection and penile protrusion
precopulatory
contraction of smooth muscle and striated muscles
ejaculation
The vomeronasal organ is unable to detect pheromones, but is a part of the olfactory system.
false: can detect hormones
The head of the sperm is comprised of what specific pieces?
acrosome, post nuclear cap, nucleus
oocyte maturation steps simplified
- mitotic division of primordial germ cells
- nuclear arrest
3.cytosplampic growth
4.resumption of meiosis following LH surge
how many chromosomes are associated with the oocyte stage
2N: primordial germ cell/ secondary oocyte with 1 polar body
4N:primary oocyte
1N: Secondary oocyte with 2 polar bodies
single cell where fusion of pronuclei has not occured
ootid
an animal in very early stages of development, where anatomical structures are not recognizable
embryo
an early embryonic stage that has a zona pellucida and blastomeres that are easily distinguished between each other
morula
a cell of a developing embryo that is totipotent
blastomere
an early embryonic stage that has a zona pellucida and blastomere that are NOT easily distinguishable
compact morula
an early embryonic stage that has a fluid filled cavity present
blastocyst
the fluid filled space of a blastocyst
blastocele cavity
What are the phases/site of fertilization
site: ampullary-isthmic junction of oviduct
phases: sperm penetration
-pronucleus formation
-sygngamy (zygote formation)
what are the steps of cleavage
zygote- 2 cell- 4 cell- 8 cell - 16 cell- morula- blastocyst
can blastocyst be found in the oviduct
false
describe the first few stages of embryonic development
AIJ, day 0-2: one cell, two polar bodies
AIJ, day 1-3: two cell, all cell divisions are mitotic
Isthmus, day 2-3: four cell
Isthmus, day 3-5: eight cell
enters uterus even if not fertilized (except mare: unfertilized remain in oviduct), day 4-5: sixteen cell (last totipotent stage)
uterus, day 5-6: morula
what is the remainder of embryonic development after morula
day 6-7, tight morula: compact morula form tight cell compact, so that blastocyst formation is possible
day 7-8, early blastocyst: fills will fluid
day 7-9, blastocyst: fluid present
expanding and hatching blastocyst: day 9-11
how does an ootid become a zygote
syngamy to make 2N
describe the cell order of a developing embryo
ootid, zygote, 2-celled embryo (blastomeres), morula, early blastocyst, hatching blastocyst, hatched blastocyst
what are the junctions in the morula and early blastocyst
gap junction: inside
tight junction: outside
sodium pumps in, water follows
what is the importance of sodium pumping into the morula
mechanism of blastocoel function
- fluid builds, gap junctions allow the cells to polarize and they end up separating into the ICM and trophoblast
