Fertilization Flashcards Preview

OS3 > Fertilization > Flashcards

Flashcards in Fertilization Deck (8)
Loading flashcards...
1
Q

Cumulus cells secrete what protective substance?

A

Hylouronic acid

2
Q

Sperm cells contain what enzyme to initially gain access to the oocyte?

A

pH 20 (hyoluronase)

3
Q

At Zona Pelucida, sperm first bind to which protein?

A

ZP-3
Triggers Alkalinization
PLC Activation
Ca2+ influx

4
Q

Which two proteins are important at the egg-plasma membrane interface for proper binding?

A

Sperm expresses IZUMO which binds to Oocyte JUNO

5
Q

What causes the oocyte to complete meiosis?

A

Penetrating sperm releases PLC-Zeta, PIP2 –>IP3 to rise in intracellular Ca2+
Intracellular Ca2+ causes completion of Metaphase II

6
Q

2 Mechanisms to prevent polyspermy

A

Rise in intracellular Ca2+ produces cortical granules
Cortical granules causes ZP-2 to become ZP-2f which cannot bind to sperm.

JUNO on oocyte is lost soon after entry of first sperm

7
Q

Mechanisms of Erection

A

Sexual Stimulation activates Cavernous Nerve
Main NT is NO
NO activates guanylyl cyclase
cGMP causes Relaxation of smooth muscle and vasodilation

8
Q

Mechanism of viagra

A

Viagra is a type 5 Phosphodiesterase Inhibitor

Prevents the breakdown of cGMP to GMP