Lecture 2 -- Fertilization Flashcards
What is the morphology of Sperm?
- Cell membrane
- Sperm Head
- Neck
- Midpiece
- Tail
- Endpiece
What is the morphology of Oocytes?
- Jelly Layer
- Zona Pellucida (Vitelline Envelope in non-mammals)
- Cell Membrane
- Cortical Granule
- Mitochondrion
- Nucleus
What are the contents of Oocytes?
- Food
- Translation Machinery
- Maternal Morphogenic Factors
- Protective Chemicals
What are the phases of Oocyte Maturation?
- Primary Oocyte
- First Metaphase
- Second Metaphase
- Meiosis complete
Why is oogenesis asymmetrical?
Oogenesis creates one large egg and 3 polar bodies.
What phase are the eggs in a female mammal’s ovary stuck in?
Second Metaphase
How many natural human fertilizations end in spontaneous embryo abortion (miscarriage)?
2/3
What is the process of Fertilization (not discrete)?
- Sperm Capacitation
- Sperm Attraction
- Zona Pellucida Recognition
- Acrosome Reaction
- Membrane Fusion
- Polyspermy Block
- Sperm Nucleus Decondensation
- Syngamy
- Co-metabolic Activation
What is Fast Polyspermy Block?
The sodium potassium pump produces a resting membrane potential of -70mV. Once a sperm has gotten through the zona pellucida and has started to fuse with the egg, the voltage shoots up. Seems to shock the other sperm.
What is the Slow Polyspermy Block?
The sperm that fertilizes the egg brings in calcium which triggers the cortical granules to expand be released thus expanding the zona pellucida to block out other sperm. Seems to happen like a barrier.
Why is the Egg bigger than the Sperm?
The Egg contains more nutrients and the DNA is less condensed than the Sperm.
What is Sperm Capacitation?
Sperm needs to be metabolically activated through acid
What is Sperm Attraction?
Sperm are both thermally and chemically attracted to the Egg.
What is the Zona Pellucida Recognition?
The Zona Pellucida seems to have a lock (made of proteins) that recognize human sperm.
What is the Acrosome Reaction?
The moment that the sperm breaks through the Zona Pellucida.
