Overview of the Menstrual Cycle

Introduction

• Presenter: Sarah
• Focus: Reproductive cycles, specifically the menstrual cycle
• Part of NCLEX review series for maternity
• Video includes quiz for self-evaluation

Key Topics to Focus On:

• Phases of the menstrual cycle
• Hormonal changes during the cycle

Menstrual Cycle Basics

• Typical cycle: 28 days
• Mid-cycle (Day 14): Ovulation
• Goal: Reproduction - preparation for potential fertilization

Changes in Ovaries and Uterus

• Ovarian Phases:
  • Follicular Phase
  • Ovulation
  • Luteal Phase
• Uterine Phases:
  • Menstrual Phase
  • Proliferative Phase
  • Secretory Phase

Ovarian Changes

Follicular Phase (Days 1-13)

• Preparation of a follicle to release a mature egg
• Hormones:
  • Gonadotropin-releasing hormone (GnRH)
  • Follicle-stimulating hormone (FSH)
  • Luteinizing hormone (LH)
• Process:
  • Hypothalamus releases GnRH
  • Anterior pituitary gland releases FSH and LH
  • FSH stimulates follicle growth
  • Only one follicle matures (Graafian follicle)
• Estrogen increases as the follicle matures

Ovulation (Day 14)

• LH surge causes the release of the mature egg
• Corpus luteum formation, secreting progesterone and estrogen

Luteal Phase (Days 15-28)

• Corpus luteum secretes high levels of progesterone
• Prepares endometrium for potential implantation
• No fertilization: Corpus luteum disintegrates, cycle restarts
• Fertilization: Embryo releases human chorionic gonadotropin (HCG)

Uterine Changes

Menstrual Phase (Days 1-6)

• Shedding of the endometrial layer (stratum functionalis)
• Triggered by drop in progesterone and estrogen

Proliferative Phase (Days 7-14)

• Rebuilding of endometrial layer
• Estrogen from the growing follicle supports this process

Secretory Phase (Days 15-28)

• Endometrium becomes receptive for implantation
• Progesterone plays a key role

Additional Information

• Fertile days: Days 9-16
• Sperm can survive in reproductive tract for up to 5 days
• Progesterone and estrogen critical for maintaining pregnancy

Important Notes

• Corpus luteum stays if fertilization occurs, supported by HCG
• Placenta eventually takes over hormone production

Conclusion

• Access free quiz on the website to reinforce knowledge
• Additional videos available in the maternity NCLEX review series
• Encouragement to subscribe for more educational content