SME
Grade 9 Science · Problem type
The menstrual cycle
Use this for “Why does menstruation stop during pregnancy?”
Put in order
Put the phases of the menstrual cycle in order, from day 1.
1
?
2
?
3
?
4
?
Assumptions
•
Hormones from the brain (FSH and LH) and the ovary (estrogen and progesterone) run the cycle.
•
If an embryo implants, it makes the hormone hCG, which keeps progesterone high, so the lining stays and menstruation stops.
•
The days are for a typical 28-day cycle; real cycles vary.
•
Menstruation is the first days of the follicular phase.
Topic check
See what you know: 5 questions on this topic
New questions each time. Pass to mark it complete.
Refresh
Related lessons
Reproduction and development
Main lesson
Sexual or asexual reproduction?
Use this for “Why do offspring from sexual reproduction differ from both parents?”
Which germ layer forms it?
Use this for “Which germ layer forms the brain and spinal cord?”
Hormone levels through a cycle
Use this for “Which hormone keeps the uterine lining in the second half of the cycle?”