Loading…
Loading…
GCSE Biology · key term
The breakdown and loss of the uterus lining when pregnancy has not occurred.
Used by AQA, Edexcel and OCR
Specification 4.5.3.4 · Paper 2
The loss of the uterus lining from the body at the beginning of a cycle when pregnancy has not occurred.
Revise: The Menstrual Cycle and Hormonal ControlDay 1 is the first day of menstruation. If pregnancy has not occurred, the uterus lining breaks down and is lost. The lining then rebuilds and thickens.
Specification 7.4, 7.5 · Paper 2
Do not confuse menstruation with ovulation: menstruation is the loss of the uterus lining, whereas ovulation is the release of an egg from an ovary.
Treat day 1 as the first day of menstruation, not the day on which ovulation occurs.
Do not say that menstruation happens immediately after ovulation: the lining is maintained for a time and breaks down if pregnancy does not occur.
Create a free account to read GCSE Biology revision notes for your exam board and track your progress.
The shedding of the uterus lining, including blood and tissue, through the vagina.
Day 1 is therefore the first day of menstruation. The average cycle is around 28 days, but cycles naturally vary: regular cycles of roughly 21–35 days can be normal. The timing below describes a typical 28-day cycle rather than an exact timetable for every person.
Specification B3.2c, B3.2d · Paper 1 (Foundation), Paper 3 (Higher)
The shedding of the uterine lining through the vagina when pregnancy has not occurred.
Revise: Hormones in human reproductionIf pregnancy does not occur, the lining is shed during menstruation, and a new cycle begins. A cycle is often described as about 28 days, but its length varies; ovulation is not guaranteed to happen on a fixed day.
The breakdown and loss of the uterine lining at the beginning of a menstrual cycle.
Paper 1 (Foundation), Paper 2 (Foundation), Paper 3 (Higher), Paper 4 (Higher)
The breakdown and discharge of the thickened uterus lining when pregnancy has not occurred.
Revise: Menstrual Cycle ControlA cycle is conventionally counted from the first day of menstruation. During menstruation, the thickened uterus lining breaks down and is discharged through the cervix and vagina.