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प्रश्न
What are the phases of the menstrual cycle? Indicate the changes in the ovary and uterus.
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उत्तर
The four phases of the menstrual cycle are:
- Menstrual or Destructive phase
- Follicular or Proliferative phase
- Ovulatory phase
- Luteal or secretory phase.
Events of the menstrual cycle and changes in the ovary and changes in the uterus.
| Phase | Days | Changes in Ovary | Changes in Uterus | Hormonal changes |
| Menstrual phase | 4 – 5 days | Development of primary follicles. | Breakdown of uterine endometrial lining leads to bleeding. | The decrease in progesterone and estrogen. |
| Follicular phase | 6th – 13th day |
Primary follicles grow to become fully mature Graafian follicles. | Endometrium regenerates through proliferation. | FSH and Oestrogen increase. |
| Ovulatory phase | 14th day | The Graafian follicle ruptures, and releases the ovum (egg). | Increase in endometrial thickness. | LH peak. |
| Luteal phase | 15th – 28th day | Emptied Graafian follicle develops into corpus luteum. | The endometrium is prepared for implantation if fertilization of the egg takes place if fertilization does not occur corpus luteum degenerates, uterine wall ruptures, bleeding starts, an unfertilized egg is expelled. | LH and FSH decrease, Corpus luteum produces progesterone, and its level increases followed by a decline if menstrual bleeding occurs. |
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संबंधित प्रश्न
Explain the events that occur in a graafian follicle at the time of ovulation and thereafter.
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Which set is similar?
A biology student after studying the different levels of hormones during the menstrual cycle was comparing 2 subjects (Patients). A table was created after looking at the levels of hormones A and B for Subjects 1 and 2. Read the information in the table and answer the question that follows.
| HORMONE A | HORMONE B | |
| Subject 1 | Shows a peak on the 14th Day of the menstrual cycle. | Falls down during the luteal phase. |
| Subject 2 | Shows a peak on the 14th Day of the menstrual cycle. | The level is maintained high in the luteal phase. |
Subject 2 has a higher level of hormone B, which is ______
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In the figure given below, parts A and B show the level of hormones which influence the menstrual cycle. Study the figure and answer the questions that follow:
- Name the organs which secrete the hormones represented in parts A and B.
- State the impact of the hormones in part B on the uterus of the human female during 6 to 15 days of the menstrual cycle.
