Final Lecture Summary - May 1st

Introduction

• Last lecture of the semester.
• Congratulations for making it to the end.
• Test six is open until Monday at 11:59 PM.

Schedule for the Week

• Monday & Wednesday: Review for the final.
• No class on Tuesday.
• Final exam initially planned for Thursday morning.
• Discussion about possibly moving the exam to Wednesday.

Lecture Content: Gastrulation

• Gastrulation: Conversion of the bilaminar disk (epiblast and hypoblast) into a trilaminar disk (three germ layers: endoderm, mesoderm, ectoderm).
• Germ Layers:
  • Endoderm: Epithelial linings of digestive, respiratory, and urogenital systems.
  • Mesoderm: Skeleton, muscles, kidneys, reproductive organs, circulatory system, dermis, dentin, serous membranes.
  • Ectoderm: Epidermis, epithelium, nervous tissue, sense organs.

Development of Male and Female

• Genetic Basis:
  • Male (XY) or Female (XX).
  • Non-disjunction can lead to variations (e.g., Turner syndrome).
• Sexual Development:
  • Mullerian Ducts: Develop into female structures (uterine tubes, uterus).
  • Wolffian Ducts: Develop into male structures (epididymis, ductus deferens).
  • Testosterone and anti-mullerian hormone influence the development of male structures.
• External Genitalia Development:
  • Male: Genital tubercle forms the penis; labial scrotal swellings form the scrotum.
  • Female: Genital tubercle forms the clitoris; labial scrotal swellings form the labia majora.

Fetal Circulation

• Pathways:
  • Umbilical vein delivers oxygenated blood.
  • Ductus venosus bypasses the liver to connect to the inferior vena cava.
  • Foramen ovale shunts blood between atria.
  • Ductus arteriosus bypasses the lungs.
• Post-birth Changes:
  • Closure of fetal shunts.

Labor and Birth

• Stages of Labor:
  • Dilation and effacement of the cervix.
  • Expulsion of the baby.
  • Delivery of placenta.
• Apgar Score: Assessment of newborn health (heart rate, respiration, color, muscle tone, reflexes).
• Positive feedback of oxytocin and prostaglandins in childbirth.

Miscellaneous

• Discussion on chromosomal testing and prenatal testing methods.
• Visual demonstration of the stages of labor.

Conclusion

• No Kahoot for this lecture.
• Review and final preparation scheduled for next week.
• Appreciation expressed to the class for their hard work and engagement throughout the semester.