Menstrual Cycle
Follicular, ovulatory and luteal phases with FSH, LH, oestrogen and progesterone. (Biology › Human Reproduction, NEET UG syllabus.)
What is Menstrual Cycle?
The cyclic changes occurring in the female reproductive system, primarily the uterus and ovaries, regulated by hormones, preparing the body for potential pregnancy.
Key points
- Describe the sequential events and phases of the menstrual cycle.
- Explain the hormonal regulation of each phase, identifying the roles of FSH, LH, estrogen, and progesterone.
- Correlate the changes occurring in the ovary with those in the uterus throughout the cycle.
- Understand the physiological consequences of fertilization or its absence on the menstrual cycle.
Common exam trap
Confusing the primary roles of FSH (follicle growth) and LH (ovulation, corpus luteum formation).
Definitions
- Term
Menstrual Cycle
- Meaning
The cyclic changes occurring in the female reproductive system, primarily the uterus and ovaries, regulated by hormones, preparing the body for potential pregnancy.
- Term
Menarche
- Meaning
The first menstruation in a female, marking the onset of puberty.
- Term
Menopause
- Meaning
The natural cessation of menstruation, typically occurring between 45 and 55 years of age.
- Term
Follicular Phase
- Meaning
The phase of the menstrual cycle characterized by the growth and maturation of ovarian follicles and proliferation of the uterine endometrium, primarily driven by FSH and estrogen.
- Term
Luteal Phase
- Meaning
The phase after ovulation, where the ruptured follicle transforms into the corpus luteum, which secretes progesterone and estrogen to maintain the uterine lining.
- Term
Ovulation
- Meaning
The release of a mature egg (secondary oocyte) from the ovarian follicle, typically triggered by an LH surge.
- Term
Corpus Luteum
- Meaning
A temporary endocrine structure formed in the ovary after ovulation from the remnants of the Graafian follicle, which primarily produces progesterone and some estrogen.
Learning objectives
Describe the sequential events and phases of the menstrual cycle.
Explain the hormonal regulation of each phase, identifying the roles of FSH, LH, estrogen, and progesterone.
Correlate the changes occurring in the ovary with those in the uterus throughout the cycle.
Understand the physiological consequences of fertilization or its absence on the menstrual cycle.
Identify the key structures involved, such as the Graafian follicle and corpus luteum.
Prerequisites
Basic understanding of the human endocrine system and hormone action.
Knowledge of the structure of the female reproductive organs (ovary, uterus).
Familiarity with the process of oogenesis and meiosis.
Common mistakes
Confusing the primary roles of FSH (follicle growth) and LH (ovulation, corpus luteum formation).
Misunderstanding the exact timing of ovulation and its triggers.
Incorrectly associating high progesterone levels with the follicular phase.
Not knowing that a decline in ovarian hormones (estrogen and progesterone) directly causes menstruation.
Forgetting the role of the corpus luteum in secreting hormones post-ovulation.
Keywords
Menstrual cycle
Follicular phase
Luteal phase
Ovulation
FSH
LH
Estrogen
Progesterone
Corpus luteum
Endometrium
Menarche
Menopause
Graafian follicle
Uterine cycle
Ovarian cycle
Practice preview
The 'LH surge' is a rapid increase in Luteinizing Hormone levels that occurs during the menstrual cycle. What is its primary consequence?…
medium
If fertilization does not occur, what hormonal change directly leads to the disintegration of the corpus luteum and the onset of menstruation?…
medium
A woman experiences irregular menstrual cycles with prolonged periods of amenorrhea (absence of menstruation). Hormonal analysis reveals consistently low levels of both oestrogen and progesterone. Which of the following …
hard