Ovarian Function Flashcards
birth to menopause
how many oocytes at these stages of development?
- 20 weeks
- birth
- puberty
20 weeks: 7 million oocytes
Birth: 1-2 million oocytes
puberty: 400,000 oocytes
birth to menopause
how many oocytes ovulate in a reproductive life span?
only 400-500 will ovulate in a reproductive life span
anatomy of ovaries
what attaches ovaries to the pelvic sidewall
- the suspensory ligaments attach the ovaries to the pelvic sidewalls
ovaries
what does ovum release respond to in ovaries?
responds to cyclic gonadotropin secretion
ovaries
what are the 2 main functions of the ovaries?
- generation of a mature fertilisable ovum (folliculogenesis)
- production of female sex hormones (steriodogenesis)
structure of the ovary
What is the outer interior part of the ovaries called?
ovarian cortex
structure of the ovaries
What is the innermost part of the ovaries called?
ovarian medulla
structure of ovary: corpus luteum
What does the corpus luteum look like and what is the function of corpus luteum?
for first part think a sac
for second part think main female hormones
- looks like a yellow empty sac
- function to produce oestrogen and progesterone
structure of ovary
what does the corpus luteum become if fetilisation does not take place?
something else that starts with corpus
- becomes the corpus albicans
embryology
What is a teratoma?
think germ cells from sperm/ovum
germ cell tumour originating from ovum or sperm cells
folliculogenesis
what is folliculogenesis?
think ovarian follicles, primordial follicles and graafian follicles
maturation of ovarian follicles leading into progression of a small number of primordial follicles into a large Graafian follicle
follicles
what is the 6 stages of follicle maturation and outline a feature of each
think layers of cells for the first 2 stages, space in the follicle for the 3rd stage, buldges for the 4th stage, ruptures for the 5th part, the colour white for the 6th part
- Primordial follicle: only 1 layer of cells
- primary follicle: 2 or more layers of cells
- secondary follicle: fluid-filled space (antrum)
- vesicular (Graafian follicle): buldge from ovary
- Corpus Luteum: ruptured follicle
- corpus albicans: white body
follicles
what is the primary aim of follicle maturation?
to support the oocyte in growth
folliculogenesis
what are the 3 stages of folliculogenesis
- recruitment
- selection
- Dominance
folliculogenesis
what happens in recruitment in folliculogenesis
think follicles departing, patterned growth and development in early follicular phase
Recruitment: process where follicle departs from the resting pool to begin well-characterised pattern of growth and development during early follicular phase
folliculogenesis
what is selection in folliculogenesis
sorting of maturing follicular cohort by atresia (the degeneration of germ cells and their associated somatic cells)
folliculogenesis
what is dominance in folliculogenesis
status of the follicle destined to ovulate given key role in regulating the size of the ovulatory quota
ovarian cycle
Outline what happens in the ovarian cycle at these times:
- Start
- 3-4 months
- 70 days
- FSH window
think about cohort growth for start,
for 3-4 months think primary follicles and what they become at 70 days
for fsh window think what happens if they have an FSH window and what happens if they dont have a FSH window
start:
- primordial follicles, everyday a cohort with start to grow
3-4 months
- primary follicles form and at 70 days primary follicles become small antral follicles (2-5mm) (still primary follicles
FSH window
- if the small antral follicles have an FSH window, they are recruited into the ovulatory cycle
- if there in no FSH window, atresia occurs
folliculogenesis
what do the healthiest follicles have the most of?
think receptors
the healthiest follicles have the most FSH receptors
folliculogenesis
when are follicles:
- FSH independent
- FSH sensitive
- FSH dependent
- LH dependent
for FSH independent, think primordial follicle and primary follicles
for FSH sensitive think primary follicle and what this becomes
for FSH dependent think secondary follicle, antral follicle and what this becomes
for LH dependent think dominant preovulatory follicle and what this becomes
- FSH independent from beginning as a primordial follicle to a multi-layer primary follicle
- FSH sensitive when multi-layer primary follicle becomes a secondary follicle
- FSH dependent when secondary follicle becomes an antral follicle to when this becomes a dominant preovulatory follicle
- LH dependent when dominant preovulatory follicle becomes an ovulating follicle
oogonia
What is the glycoprotein extracellular matrix that mature human eggs secretes and what does it act as
- zona pellucida
- acts as a selective physical barrier
oogonia
what does teh zona pellucida prevent?
prevents polyspermy
oogonia
what is the largest cell in the human body?
the human egg/ovum
Steroidogenesis
what enzyme converts adrostenedione, testosterone and dihydrotestoterone into the oestrogens?
aromatase
