The Menstrual Cycle
A Biological Overview
Understanding the Female Reproductive System
Biology Presentation
Presented by Ms. Julie
What is the Menstrual Cycle?
The menstrual cycle is a natural process in the female reproductive system.
- Lasts 28 days on average (21–35 days is normal)
- Four main phases controlled by hormones
- Prepares the body for potential pregnancy
Phase 1
Menstruation
Days 1–5
- Uterine lining sheds (bleeding)
- Low estrogen and progesterone
- May cause cramps, fatigue
Key: Marks the start of a new cycle.
Phase 2
Follicular Phase
Days 6–14
- FSH rises, follicles develop
- Estrogen increases
- Uterine lining thickens
- Energy typically increases
Phase 3
Ovulation
Day ~14
- LH surge triggers egg release
- Egg travels through fallopian tube
- Peak fertility window
Key: Most fertile phase of the cycle.
Phase 4
Luteal Phase
Days 15–28
- Corpus luteum forms
- Progesterone rises
- PMS symptoms may occur
- If no pregnancy → cycle restarts
Cycle Summary
| Phase |
Days |
Key Event |
| Menstruation |
1–5 |
Uterine lining sheds |
| Follicular |
6–14 |
Follicles develop |
| Ovulation |
~14 |
Egg released |
| Luteal |
15–28 |
Lining thickens |
Thank You
The menstrual cycle is a vital biological process.
- Prepares body for pregnancy
- Reflects reproductive health
- Varies naturally per person
Remember: Consult healthcare providers for personalized information.