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प्रश्न
Why does menstruation occur? Describe the menstrual cycle in human females (or women).
उत्तर
Menstruation occurs due to the rupture or removal of the inner, thick and soft lining of the uterus when fertilisation does not take place.
The menstrual cycle of a female is as follows:
- After a female attains puberty, every month one of the ova of the ovary matures and gets released once in every 28 days by the process of ovulation.
- The lining of the uterus becomes thick and spongy before ovulation in order to receive the fertilised egg. If the egg is not fertilised, this lining of the uterus breaks and comes out of the vagina in the form of blood known as menstrual flow.
- This occurs on the 14th day of ovulation and lasts for 3-5 days.
- After this flow stops, the uterus starts preparing itself again for the fertilised egg. If it does not receive the fertilised egg, the same set of events are repeated.
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संबंधित प्रश्न
State its functions in case of a pregnant human female.
What are the changes seen in girls at the time of puberty?
Newly formed DNA copies may not be identical at times. Give one reason.
What is gestation period? How much is the gestation period in humans?
What is the scientific name of birth canal?
Given below is a diagram of two systems together in the human body.
 |
- Name the systems.
- Name the parts numbered 1-10.
- Describe the functions of the parts 3, 4, 5 & 6.
- What will happen if the part 3 on both sides gets blocked?
List two changes observed in girls at the time of puberty.
Define the following:
Asexual reproduction
Explain the term Parturition or birth.
State the Location:
Uterus
