Female Reproductive System Lecture Notes

Introduction

• Focus on conception and early stages of pregnancy.
• Challenges in the meeting of sperm and ova for conception.

Conception Parameters

• Sperm Viability:
  • Sperm must be introduced 5 days before to 1 day after ovulation.
  • Sperm can last 4-6 days in female reproductive tissues.
• Egg Viability:
  • Egg is viable 24-48 hours post-ovulation.
  • Conception most likely occurs in the fallopian tube.

Ovulation and Movement of the Egg

• Structure Overview:
  • Image showing uterus, fallopian tubes, and ovaries.
• Fimbria Movement:
  • Fimbria have smooth muscle cells pushing ova towards fallopian tubes.
  • Epithelial cells with cilia help move ova.
• Fallopian Tube Journey:
  • Cilia and hormone-induced contractions aid egg movement.
  • Slow movement takes up to 4 days to reach the uterus.

Role of Estrogen and Progesterone

• Hormonal Influence:
  • Contractions of fallopian tubes.
  • Help sperm movement towards ova.

Sperm Journey

• Ejaculation and Movement:
  • Propulsion aids movement to cervix.
  • Mucus in vagina and uterus is acidic, breaking down bacteria and sperm.
• Facilitation by Estrogen:
  • Loosens mucus for easier sperm travel.
• Mortality Rate:
  • High mortality due to acidic environment.
  • Only a few hundred sperm reach the ova.

Sperm Activation and Fertilization

• Capacitation:
  • Secretions in fallopian tubes activate sperm.
• Acrosome Reaction:
  • Enzymes break down ova's protective layers.
• Key Structures:
  • Cortical granules prevent polyspermy by blocking additional sperm after the first one penetrates.

Post-Fertilization and Development

• Formation of Zygote and Blastocyst:
  • Mitotic activity begins immediately post-fertilization.
  • Blastocyst forms with inner cell mass and tropoblast.
• Implantation Process:
  • Blastocyst implants in uterine wall, forming the chorion and chorionic villi.
  • Chorion develops into the placenta.

Hormonal Changes and Pregnancy Detection

• Human Chorionic Gonadotropin (HCG):
  • Indicates pregnancy and supports placenta development.
• Estrogen and Progesterone:
  • Necessary for pregnancy progression and fetal development.

Placenta Development

• Structure and Function:
  • Incorporates maternal blood vessels for nutrient supply.
  • Produces hormones critical for maintaining pregnancy.

Conclusion

• End of semester lecture on female reproduction.
• Encouragement to review content and ask questions.