Flashcards in MENSTRUAL CYCLE Deck (45)
what are the stages of the menstrual cycle?
when does the follicular phase occur?
days 1 - 13/14
when does ovulation occur?
when does the luteal phase occur?
what is the primordial follicle?
1 oocyte surrounded by granulosa cells
what does the primordial follicle secrete?
what is the primary follicle?
the oocyte grows and is separated from the granulosa cells by the zona pellucida
they contain glycoproteins
what is the role of glycoproteins in the primary follicle?
they are used for binding sperm
what are pre-antral follicles?
granulosa cells differentiate into theca cells
the 2 cells function together for oestrogen synthesis
what are early antral follicles?
the primary oocyte is full-sized
the antrum forms and is filled with fluid from granulosa cells
what is the role of gap junctions between granulosa cells and the oocyte in primary follicles?
nutrients and chemical messengers are passed to the oocyte
when and how many mature follicles produced?
at the beginning of each menstrual cycle
what happens to non-dominant follicles in the menstrual cycle?
they undergo atresia (die)
what is the graafian follicle?
it is the dominant mature follicle
it increases in size and so does the antrum
what triggers the first meiotic division of the primary oocyte and what does it produce?
what is ovulation?
the thin walls of the follicle and ovary rupture at the site where they are joined by enzymatic digestion
the secondary oocyte is carried out of the ovary by antral fluid
what happens in the follicular phase of the menstrual cycle?
- oocyte in primordial follicle grows and and separates from granulosa cells by zona pellucida (primary follicle)
- granulosa cells differentiate into theca cells (preantral cells)
- the primary oocyte is full size and antrum forms and fills with fluid (early antral cells)
- one primary oocyte becomes dominant and the rest undergo atresia. Primary oocyte undergoes first division to become secondary oocyte
- undergoes ovulation
what happens in the luteal phase of the menstrual cycle?
- after ovulation the follicle collapses
- granulosa cells increase in size and becomes the corpus luteum
- if the egg is not fertilised after 10 days it undergoes apoptosis
- this triggers menstruation
- once it collapses it is called corpus albicans
what are the phases of uterine changes in the menstrual cyccle?
when does the menstrual phase of uterine changes occur?
when does the proliferative phase of uterine changes occur?
when does the secretory phase of uterine changes occur?
what happens in the menstrual phase of uterine changes?
withdrawal of progesterone leads to endometrial degeneration - this is the trigger for menstrual flow
what happens in the proliferative phase of uterine changes?
oestrogen from granulosa cells and theca cells causes the endometrium to thicken
this stimulates the myometrium
this stimulates progesterone receptor generation in the endometrium
what happens in the secretory phase of uterine changes?
progesterone binds with its receptors in the endometrium
endometrium secretes glycogen from glandular epithelium - this provides a hospitable environment which is nourishing to sperm and oocyte
progesterone overrides oestrogen to prevent myometrium contraction and prostaglandin secretion
what is the role of glycogen secretions in the uterus during the secretory phase?
it provides a hospitable environment which is nourishing to sperm and oocyte
what is the role of progesterone in the uterus during the secretory phase?
it overrides oestrogen to prevent myometrium contraction and prostaglandin secretion
what is mucus secretion like when there are high oestrogen levels?
abundant, clear and watery mucus - this is good for sperm movement and implantation
what is mucus secretion like when there is progesterone and oestrogen?
thick and sticky
it stops bacteria from entering and offers protection to the implanted egg