Fertilization Mechanism Flashcards

1
Q

shell around human egg

A

zona pellucida (ZP1-4)

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2
Q

The _____ releases the egg from the germinal vesicle and completes meoisis I

A

LH surge

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3
Q

____ cells surround the ZP

A

cumulous cells

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4
Q

Capacitation

A

process that ensures sperm can fertilize an egg –> e.g. motility increase due to cAMP, loss of cholesterol from plasma membrane, chang ein surface charge, change in ion conductance, elevation of intracellular pH

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5
Q

With the help of _____, a cell surface _____, capacitated sperm penetrate the cumulus oophorus

A

PH20 –> surface hyaluronidase

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6
Q

ZP ___ is most crucial for egg/sperm interaction

A

ZP3

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7
Q

Only after ____ can the sperm fuse with the egg plasma membrane

A

acrosomal reaction

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8
Q

____ releases GPI linked proteins from the sperm surface and inner acrosomal matrix in the process of enzymatic hydrolysis of the ZP.

A

angiotensin converting enzymes

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9
Q

T/F penetration of the ZP requires motile force from sperm.

A

T –> in addition to enzymatic hydrolysis

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10
Q

____ plane of the sperm head attaches to the plasma membrane of the oocyte during adhesion and membrane fusion

A

equatorial plane –> 3 hours

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11
Q

Fertilization induced calcium oscillations

A

early event is increase in egg cytosolic calcium –> triggered by PLC

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12
Q

_______ are released after fertilization to prevent other sperm from penetrating.

A

cortical granules

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13
Q

At the ___ stage, cell boundaries are not visible anymore due to ____

A

morula –> compaction

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14
Q

Frequency of polyspermy after ovulation

A

1-2%

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15
Q

T/F polyspermy may be 30% if mating is delayed after ovulation/aged eggs

A

T

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16
Q

In humans, where is the block to polyspermy?

A

level of ZP as well as membrane

17
Q

Can oocyte activation occur without sperm?

A

Yes –> parthenogenesis due to mechanical trauma, temperature shock, ICSI, etc.

18
Q

intrauterine insemination

A

seminal fluid washed out –> sperm in alkaline buffer for capacitation –> intrauterine insemination

19
Q

Approximately how long after LH surge will ovulation take place?

A

36 hours

20
Q

Indication for intrauterine insemination

A

mild to moderate male factor infertility

21
Q

Intracytoplasmic sperm injection (ICSI)

A

sperm injected into egg directly