IC4 Flashcards
ovarian cycle general
- 2 alternating phases
- 28 day cycle
- interrupted by pregnancy
- terminated by menopause
ovarian cycle phase - follicular phase - general
- dominated by presence of maturing follicles
- start at puberty (hypothalamus increase GnRH production)
ovarian cycle phase - follicular phase - action of GnRH
- stimulate anterior pituitary gland to secrete LH & FSH for synthesis & secretion of estrogen by follicular cell
ovarian cycle phase - follicular phase - action of FSH
1) aid follicle growth & maturation
2) induce antrum formation (liquid space, store estrogen)
ovarian cycle phase - follicular phase - negative feedback
- in response to moderate level of estrogen
- hypothalamus inhibit GnRH secretion
- anterior pituitary inhibit FSH secretion
- follicular cell secrete inhibin -> inhibit FSH secretion
- LH continue to rise slowly -> increase in estrogen + maturation of follicle
ovarian cycle phase - follicular phase - positive feedback
- in response to high levels of estrogen
- act on hypothalamus & pituitary gland -> increase GnRH & selectively stimulate LH secretion -> surge in LH secretion -> differentiation of follicular cell into luteal cell + ovulation occur
- follicular cell secrete inhibin -> selectively inhibit FSH
ovarian cycle phases - luteal phase - identifying feature
presence of corpus luteum
ovarian cycle phases - luteal phase - what happens when fertilisation occurs
under the presence of LH, corpus luteum secretes:
1) estrogen
2) progesterone
- inhibit LH & FSH to prevent maturation of new follicle & ovulation
ovarian cycle phases - luteal phase - what happens when no fertilisation occurs
corpus luteum degenerate -> X estrogen/progesterone produced -> inhibit negative feedback -> new follicular phase
uterine cycle (menstrual cycle) - significance
1) reflect cyclic changes of female sex hormone during ovarian cycle
2) prepare female reproductive tract for fertilisation & implantation of ovum
uterine cycle (menstrual cycle) - endometrial changes
1) start of follicular phase: menses
- destruction of functional zone
2) end of follicular phase: proliferative phase
- repair & regeneration of functional zone
3) luteal phase: secretory phase
- secretion of endometrial glands
what is female puberty triggered by
GnRH released at puberty
what are the signs of female puberty
1) thelarche: earliest, develop breast
2) pubarche: growth of pubic & axillary hair
3) menarche: first menstrual period
4) growth of secondary sex organs
5) fat deposition
6) rapid increase in height
why does low body weight delay puberty in girls?
low body weight = lesser fat distribution = lower production of hormones (steroid moiety)
signs of menopause
1) X menstrual cycle
2) Atrophy of genital organs
3) vasomotor change
4) skin, emotional, psychological change
5) increase cholesterol level
6) increase risk of osteoporosis
menstrual disorders
1) amenorrhea (lack bleeding)
2) dysmenorrhea (pain)
3) menorrhagia (excess blood)
4) metrorrhagia (irregular blood)