Fertilization (Foundations Final Exam)

Front 1

fertilization

Back 1

fusion of male and female gametes

Front 2

where does fertilization normal occur?

Back 2

ampullary region of uterine tube (fallopian tube, oviduct)

Front 3

capacitation

Back 3

removal of glycoproteins that surround the sperm head prior to fertilization
- essential for fertilization to occur

Front 4

cumulus oophorus

Back 4

entire tissue outside of the egg

Front 5

corona radiata

Back 5

outer layer which contains associated granulose cells

Front 6

zona pellucida

Back 6

inner glycoprotein layer surrounding egg

Front 7

fast block

Back 7

change in membrane potential that prevents further sperm fusion events

Front 8

slow block

Back 8

at the time of sperm entry, the ovum undergoes a cortical reaction

Front 9

cortical reaction

Back 9

where the membrane of the ovum separates from zone pellucid to form a perivitelline space
- digestive enzymes are released into the perivitelline space

Front 10

reductional division

Back 10

early mitotic divisions take place without intervening growth of resultant daughter cells
- single fertilized egg produces a larger number of smaller cells

Front 11

morula ("mulberry") stage

Back 11

8-16 cell stage

Front 12

attachment of embryo to uterine wall

Back 12

- mediated by selection adhesion
- trophoblast cells express L-selectin on surface-->adhere to oligosaccharide molecules on uterine wall

Front 13

synchtiotrophoblast

Back 13

a group of trophoblast cells close to the inner cel mass
- multinuclear cells that lead invasion into endometrium and will eventually cover the cytotrophoblast

Front 14

syncytin

Back 14

retroviral protein
- regulates the ability of trophoblast cells to fuse to form synchiotrophoblast
- important for fusion of embryonic and maternal blood vessels

Front 15

dizygotic or fraternal twins

Back 15

2/3 of twins
- result from two separate ovulation and fertilization events and two separate implantations

Front 16

monozygotic or identical twins

Back 16

1/3 of twins
- due to splitting of fertilized egg during the very early cleavage stages (before 8 cells-uncompacted)
- may occur by formation of two inner cell masses within the blastocyst