Lab 11

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Lab 11

• Survey of Embryonic Development

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Lab 11

• sea urchin early development wet lab
• hormonal controls of the menstrual (ovarian and
  uterine) cycles
• fertilization, implantation, and early
  development
• final lab practical this time next week

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Sea Urchin Anatomy
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Sea Urchin Egg

• During each breeding season a sea urchin female
  spawns 400 million eggs.
• 100 micrometers in diameter (same size as a
  human egg)

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Sea Urchin Sperm

• Sea Urchin male releases 100 billion sperm

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Sea Urchin Early Development
fertilization
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Fertilization

• The sea urchin has become a classical model for
  the study of fertilization.
• Five Steps in Fertilization
• Chemotaxis
• Acrosome Reaction
• Sperm-Egg Adhesion
• Plasma Membrane Contact
• Gamete Fusion

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The Events which Occur in the Egg with Gamete
Contact Fusion
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The Change in Membrane Potential in Egg is the
Fast Block to Polyspermy
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The Cortical Reactions Raise the Fertilization
Envelope Provide the Slow Block to Polyspermy
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Sea Urchin Early Development
zygote and egg reactions
cleavage
morula
blastula
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Sea Urchin Early Development
gastrula
pluteus larva
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Ovulation
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Ovarian and Menstrual Cycle Regulation
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Figure 29.2A Sperm penetration and the cortical
reaction
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Figure 29.3 Events immediately following sperm
penetration
zygote formation
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Figure 29.4 Cleavage is a rapid series of
mitotic divisions that begins with the zygote and
ends with the blastocyst
Cleavage and Implantation
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Figure 29.7A,B,C Events of placentation, early
embryonic development and formation of the
embryonic membranes
hCG human Chorionic Gonadotropin signals
placenta formation after implantation
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Figure 29.7D Events of placentation, early
embryonic development and formation of the
embryonic membranes
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Labor and Delivery Lactation
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When and Where Will It All End?
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End Lab 11
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