Ovaries, Uterus, and Fertilization lecture 10

what happens in the ovarian cycle, follicular phase

is when the Oocytes in arrested follicles

Cells surrounding primary oocyte grow

Cells surrounding follicle become stratified (Granulosa Cells)

Produce estrogen (support egg)

Egg begins making zona pellucida

Liquid accumulates between granulosa cells

Antrum formed (fluid filled cavity)

Non-dominant follicles die

how long does it take the follicular phase happen

it take a year

what happens in the ovarian cycle, ovulation

is when Secondary Oocyte (Eggs) released may cause middle pain

the unselected follicles die

More than one oocyte released

yes, and twins can be produced,

fraternal (Different eggs)

identical (same egg)

what happens in the ovarian cycle, luteal phase

when the remaining granulosa cells form Corpus luteum

corpus luteum makes Progesterone and Estrogen

No pregnancy the corpus luteum degenerates leaving a scar

the uterine cycle (menstrual cycle), what happens in the menstrual phase

Hormones low

Uterus sheds endometrium

the uterine cycle (menstrual cycle), what happens in the proliferative phase

the Endometrium rebuilds

-Granulosa cells make estrogen

-Ovulation occurs

the uterine cycle (menstrual cycle), what happens in the secretory phase

Corpus luteum secretes hormones (Prepares endometrium for embryo)

No embryo the degenerating corpus luteum and endometrium

what does the FSH and LH

FSH => Stimulates follicles (estrogen)

LH=> Ovulation, Progesterone via Corpus Luteum

Secretions in female tract degrade what

protective sperm membrane that allows enzyme release

how does the sperm enter the egg

the sperm release enzymes degrade Zona pellucida (100s of sperm needed for digestion)

Sperm binds receptors on egg

Only one sperm enters Oocyte, how it this process protected

with a process called Polysperm block

where Ca2+ wave occurs

Granules release enzymes that destroy receptors so that no other sperm can bind to the egg

Meiosis completed

How does fertilization happens

Sperm’s chromosomes combine with egg’s.

creating a zygote

Combined chromosomes replicate & cell division begins.