Define menstrual cycle and explain its various phases with diagram.
Define menstrual cycle and explain its various phases with diagram.
Menstrual cycle:-
- The menstrual cycle is a reproductive cycle that takes place in the females of the group of primates.
- When an ovum is unfertilized, the uterus lining sheds and leads to a hemorrhage, called menstruation.
- In a girl, menstruation starts from the age ranging between 10 and 13 when she attains puberty and this beginning is known as menarche.
- The ending of menstruation is known as menopause which takes place at the age range of 45 to 50 years.
- The first day of bleeding is marked as the first day of a menstrual cycle and the period from one menstrual cycle to another can vary from 28 to 30 days.
Phases of the menstrual cycle:- There are four phases in the menstrual cycle
1. Menstrual phase 2. Follicular phase
3. Ovulatory phase 4. Luteal phase
1. Menstrual phase: On day 1, the uterus lining which is prepared for implantation starts to shed which lasts 3 to 5 days.
2. Follicular phase: A matured egg follicle releases an egg from one of the ovaries. Also, the uterus starts preparing for another pregnancy.
3. Ovulatory phase: Mid-cycle phase, is the phase in which ovulation takes place i.e., day 13-17. The end of the follicular phase along with the ovulation period defines the fertilization period.
4. Luteal phase: Post ovulation phase where the fate of the corpus luteum is decided. If fertilization occurs, pregnancy starts. If fertilization doesn’t occur, it marks the onset of another cycle.
Uterine changes: Under the influence of progesterone, there is an increase in the thickness of the endometrium. Endometrial glands grow and become secretory. Progesterone is responsible for the maintenance of pregnancy. When a fertilized ovum reaches the uterus, it is implanted and the placenta is formed. Till the placenta becomes functional corpus luteum keeps on producing progesterone. But when the progesterone source is cut off, endometrium sloughs off and menstruation begins.
Menstrual cycle:-
- The menstrual cycle is a reproductive cycle that takes place in the females of the group of primates.
- When an ovum is unfertilized, the uterus lining sheds and leads to a hemorrhage, called menstruation.
- In a girl, menstruation starts from the age ranging between 10 and 13 when she attains puberty and this beginning is known as menarche.
- The ending of menstruation is known as menopause which takes place at the age range of 45 to 50 years.
- The first day of bleeding is marked as the first day of a menstrual cycle and the period from one menstrual cycle to another can vary from 28 to 30 days.
Phases of the menstrual cycle:- There are four phases in the menstrual cycle
1. Menstrual phase 2. Follicular phase
3. Ovulatory phase 4. Luteal phase
1. Menstrual phase: On day 1, the uterus lining which is prepared for implantation starts to shed which lasts 3 to 5 days.
2. Follicular phase: A matured egg follicle releases an egg from one of the ovaries. Also, the uterus starts preparing for another pregnancy.
3. Ovulatory phase: Mid-cycle phase, is the phase in which ovulation takes place i.e., day 13-17. The end of the follicular phase along with the ovulation period defines the fertilization period.
4. Luteal phase: Post ovulation phase where the fate of the corpus luteum is decided. If fertilization occurs, pregnancy starts. If fertilization doesn’t occur, it marks the onset of another cycle.
Uterine changes: Under the influence of progesterone, there is an increase in the thickness of the endometrium. Endometrial glands grow and become secretory. Progesterone is responsible for the maintenance of pregnancy. When a fertilized ovum reaches the uterus, it is implanted and the placenta is formed. Till the placenta becomes functional corpus luteum keeps on producing progesterone. But when the progesterone source is cut off, endometrium sloughs off and menstruation begins.
