The Bio Brief

Every month:

 Ovary releases one egg.

 Uterus prepares for pregnancy

But…

 If no sperm meets the egg

 No fertilisation happens

Then the body removes the prepared lining.

 Step-by-Step

1. Ovary releases an egg.
2. Egg lives for about 1 day.
3. Uterus lining becomes thick and spongy to receive baby.
4. If fertilisation does NOT happen:
   • Egg dies.
   • Thick uterine lining is not needed.
5. This lining breaks and comes out through vagina as:
   • Blood
   • Mucus

 This process is called MENSTRUATION.

 Flow Chart: Egg Not Fertilised

Egg released from ovary

          ↓

Egg not fertilised

          ↓

Egg dies

          ↓

Uterus lining breaks

          ↓

Blood + mucus come out

          ↓

Menstruation

 Menstruation

What is it?

 Monthly shedding of uterine lining when pregnancy does not occur.

 Duration:

 Usually 2–8 days

Happens:

About once every month

 Simple Diagram

Uterus lining breaks

        ↓

Blood flows out

        ↓

Vagina

 One-Line Definition

 Menstruation is the monthly discharge of blood and uterine lining through the vagina when fertilisation does not occur.

 Key Points to Remember

 Egg survives only 1 day.

 Uterus prepares every month.

 No fertilisation → lining sheds.

Process repeats monthly.

Called menstruation