Embryology Week 1 Flashcards
Which glands controls sexual cycles in females and how
- hypothalamus release gonadotropin releasing hormone ( GnRH )
- acts on cells of anterior lobe of pituitary gland ( adenohypophysis ) releases gonadotropins follicule stimulating hormone and lutenizing hormone
Function of FSH
- does not develop primordial to 1• but without it oocytes become atretic and die
- stimulate growth of granulosa around oocyte
- stimulate development of growing oocyte into vesicular
How many ooctyes reach maturity , how many discharged and what happens to the rest
- 15-20
- 1
- degenerate and replaced by CT forming corpus atreticum
Function of growth differentiation factor 9
-proliferation of granulosa
How is estrogen formed and other product formed
-theca produces testosterone and granulosa converts it to estrogen and 17 Beta estradiol
Effect of estrogen
1 uterine endometrium enters follicular phase
2 stimulate adenohypophysis LH production
3 thins cervical mucus to allow sperm to pass through
Function of LH
- develops Vesicular into graafian stage
- elevates maturation promoting factors causing ooctyes to complete meiosis 1 and initiate 2
- causes follicular rupture and ovulation
- stimulates production of progesterone by follicular stromal cells ( lutenization )
State of meiosis and ovary before ovulation
- meiosis 1 complete and 2 arrested at metaphase 3 hours before ovulation
- ovary bulges at apex spot , stigma appears
Effects of high LH
- high LH levels increase collagenase activity to digest CT around follicule
- prostaglandin increases and causes local muscle contractions in the ovarian wall to extrude oocyte and cumulus oophorus ( ovulation )
What is corpus Luteum and corona radiata
- follicule without cumulus oophorus and oocyte
- cumulus oophorus cells rearranged around zona pellucida
How is corpus luteum formed and function
- granulosa and theca are vascularized under LH influence
- develop yellowing pigment and differentiate into lutein cells to form
-secrete estrogen and progesterone to develop uterine mucosal to enter secretary stage to prepare for implantation
How is ovary swept into fallopian / uterine tubes
- fimbrilae sweep over surface of tube and begin to contact rhythmically
- oocyte and radiata carried into tube by rhythmic pattern
What happens to oocyte and oophorus once in tube
How is oocyte moved though uterine tube and what controls the rate
How many days for fertilized oocyte to reach uterine lumen
-cumulus withdraws cyto processes , lose contact with oocyte and rearranges into radiata
/peristaltic muscles contractions of tube and ciliary epi
- endocrine status during and after ovulation
- 3 to 4 days
How is corpus alibican formed
-if fertilization does not occur luteum reaches max development after 9 days.
-luteum shrinks due to luteolysis ( degeneration of lutein cells )
And forms mass of fibrocytotic scar tissue called corpus alibicans
What happens to luteum if oocyte fertilized
- degeneration of corpus luteum prevented by human chorionic gonadotropin secreted by synctiotrophoblast of embryo
- luteum grows and forms corpus luteum graviditatis ( of pregnancy )
What happens to graviditatis at end of 1st trimester and end of 4th month
What happens if graviditatis is removed 4 months before
How does luteum grow
- 1/3 to half of ovary
- regresses slowly as placenta secretion of progesterone is sufficient
- abortion
- hypertrophy and accumulation of lipid
Function of progesterone and where secreted
- secreted by corpus luteum
- prepares uterus for pregnancy
Ampullae location and function
- immediately after fimbrilallae
- site of fertilization