Advertisements
Advertisements
प्रश्न
What is the menstrual cycle?
Briefly describe the menstrual cycle.
उत्तर १
Female reproductive system undergoes some changes (that prepare the uterus for pregnancy) at puberty and those changes repeat at an interval of every 28-30 days. Such repetitive changes are called the menstrual cycle.
उत्तर २
The beginning of the menstrual cycle marks the onset of puberty in human females. Menstruation occurs if an ovum released by the ovary of a woman is not fertilized during ovulation. This is described below.
-
When a girl reaches puberty at the age of about 10, the sex hormones released into her blood cause some of the ova (or egg cells) in her ovaries to become mature (or ripe).
-
Usually, one mature ovum (or egg) is released off (jm one of the ovaries into the oviduct once every 28 days. This is called ovulation.
-
Before ovulation (or release of ovum), the inner wall of the uterus becomes thick and spongy, and full of tiny blood vessels to receive the fertilized ovum.
-
If the ovum does not get fertilized then the thick and soft inner lining of the uterus breaks. So, the thick and soft inner lining of the uterus along with the blood vessels and the dead ovum comes out of the vagina in the form of bleeding called menstruation.
-
Menstruation usually occurs 14 days after ovulation and usually lasts for about 3 to 5 days.
-
After menstruation is over, the inner lining of the uterus starts building up again so that it may become ready to receive the next ovum.
-
If the ovum does not get fertilized even now, then menstruation takes place again. This cycle of menstruation is repeated again and again in women after every 28 days. The menstrual cycle is controlled by hormones.
Menstruation stops temporarily when the ovum gets fertilized and the woman gets pregnant. Menstruation also stops due to nutritional deficiencies, low body weight, stress, eating disorders, excessive weight gain, etc.
संबंधित प्रश्न
Explain the role of pituitary and the ovarian hormones in menstrual cycle in human females
The Graafian follicle, after ovulation turns into a hormone producing issue called Corpus callosum.
Briefly describe the secretory phase of the menstrual cycle.
Define: Menarche
Give Reasons
The chances of pregnancy to occur are most favourable on or about the 14th day of the menstrual cycle. Explain.
Read the following passage and answer the question that follows:
Rahini and her parents were watching a television program. An advertisement flashed on the screen which was promoting the use of sanitary napkins. Rahini’s parents suddenly changed the channel, but she objected to her parents and explained the need and importance of such an advertisement.
List out the napkin hygiene measures taken during menstruation?
Read the following passage and answer the question that follows:
Rahini and her parents were watching a television program. An advertisement flashed on the screen which was promoting the use of sanitary napkins. Rahini’s parents suddenly changed the channel, but she objected to her parents and explained the need and importance of such an advertisement.
Do you think that Rahini’s objection towards her parents was correct? If so, Why?
What are the phases of the menstrual cycle? Indicate the changes in the ovary and uterus.
Explain the various phases of the menstrual cycle.
Detection of which hormone in urine is an indicator of pregnancy?
During which phase of the menstrual cycle does the endometrium thicken up to 8-10 mm?
Lack of which hormone results in menstrual flow?
In humans, the menstrual cycle is generally of ______.
In the absence of fertilization, corpus luteum ____________.
All occur during follicular phase of menstrual cycle, EXCEPT
____________ is transformed to corpus luteum during luteal phase of the menstrual cycle.
Corpus luteum produces ______.
Immediately after ovulation, the mammalian egg is covered by a membrane known as ______.
Withdrawal of which of the following hormones is the immediate cause of menstruation?
Which one of the following is the correct matching of the events occurring during menstrual cycle?
Corpus luteum ______.
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. |
Which of the following statements is true about the subjects?
Distinguish between pollination and fertilisation. Mention the site and product of fertilisation in a flower.
Draw a neat, labelled diagram of a pistil showing pollen tube growth and its entry into the ovule.
Which of the following events is not associated with ovulation in human females?
After ovulation the collapsed ovarian follicle shrinks and becomes filled with cell to form:
Answer the following questions by observing the diagram of menstrual cycle:
- What is the period of menstruation?
- On which day does ovulation occur during the menstrual cycle?
- In the menstrual cycle which reproductive organs undergo changes?
- Which period is said to be the period of regeneration of endometrium?
- Which period is said to be the period of secretions of glands in endometrium?
The graph given below shows the number of primordial follicles per ovary in women at different ages. Study the graph and answer the questions that follow.
- What is the average age of the women at the onset of menopause?
- At what age are maximum primordial follicles present in the ovary, according to the given graph?
Complete the table:
| Number | Type | No. of pairs | Region |
| C1C8 | Cervical | ______ | Neck |
| T1T12 | ______ | 12 pairs | ______ |
| L1L5 | Lumbar | ______ | Lower back |
| S1S5 | ______ | 5 pairs | ______ |
| CO1 | Coccygeal | ______ | ______ |
The onset of menstruation in women is called ______.
