Endo E3 Pt2

Front 1

3 major endometrial cycles

Back 1

menstrual, proliferative and secretory phases

Front 2

what causes menstrual phase

Back 2

high levels of E&P suppress LH levels, diminishing CL. Degeneration of endometrium occurs

Front 3

what causes proliferative phase

Back 3

estrogen produced by follicle development

Front 4

what causes secretory phase

Back 4

The rise of E triggers LH surge. This surge triggers CL to produce P and E.

Front 5

after menstruation, what happens to endometrium

Back 5

it is restored by proliferation of epithelial and stromal cells.

Front 6

what drives the proliferation of cells that make up endometrium

Back 6

estrogen secreted by granulosa cells of developing follicles

Front 7

what happens during early secretory phase

Back 7

P stimulates secretory changes in tissue

Front 8

what happens in middle to late secretory phase`

Back 8

endometrial glands become filled with secretions. Lasts 20 days.

Front 9

what are the events in pregnancy

Back 9

fertilization, implantation, placentation, and parturition

Front 10

what happens to fertilized ovum

Back 10

stays in fallopian tube for 3 days and becomes morula

Front 11

define preimplantation

Back 11

the morula enters uterus and stays free floating for 72hrs. embryo is nourished by uterus that makes proteins

Front 12

what role does endometrium play in preimplantation

Back 12

it only has a 19-23 day window that it is receptive; receptivity controlled by hormones

Front 13

what signals does the embryo synthesize and why

Back 13

human chorionic gonadotropin- sustains CL, which is asource of progesteron

immunosuppressive agents- control mothers immune response

proteases- facilitate invasion of trophoblast into the endometrium

Front 14

phases of embryo implantation

Back 14

apposition, adhesion, and invasion

Front 15

what role does zona pelucida play in embryo hatching

Back 15

it surrounds the blastocyst degenerates brofre initiation of implantation

Front 16

define apposition

Back 16

initial loose contact between the trophectoderm and endometrium

Front 17

define adhesion

Back 17

adhesion of trophoblast to uterine epithelium via ligand receptor. This dislodges uterine epithelial cells from their basal lamina, making it easier to access trophoblast to basal lamina for penetration into stromal layer

Front 18

define invasion

Back 18

trophoblast secretes secretions that simulate invasion of the endometrium and have root like projections that get blood supply

Front 19

after invasion of the cell, what happens

Back 19

it becomes decidual cells/decidua. Needs progesterone

Front 20

function of placenta

Back 20

carries oxygen, removes CO2 and waste from fetus

Front 21

what happens after implantation

Back 21

syncytiotrophoblast invades stroma of uterus. Within the blasts, are lacunae, fluid filled holes. 12 days later, it connects to veins. Cytotrophoblasts create small mounds known as primary chorionic villi. They eventually become secondary chorionic villus

Front 22

characteristics of mature placenta

Back 22

outer surface of chorionic villus is covered with thin layer of syncytiotrophoblast. Lacunae merge into one.

Front 23

what hormones are secreted by placenta

Back 23

hCg, progesterone, and estrogen

Front 24

what is meant with the concept of maternal placental fetal uit

Back 24

the placenta cannot make steroid hormones alone. Mother and fetus need to make em

Front 25

what role does LDL cholesterol play

Back 25

it is converted to progesterone by placenta and sent to mother

Front 26

what are the three enzymes that placenta lacks for estrogen biosynthesis

Back 26

fetal adrenal gland, liver supply-estrogen precursor and DHEA.

Front 27

how doe fetus protect itself from exposure to high levels of steroid hormones

Back 27

fetus conjugates steroid hormones to sulfate to reduce activity of hormones.