pregnancy physiology part 1

Question 1

when must fertilisation occur after ovulation?

Answer 1

24 hrs

Question 2

where does fertilisation occur?

Answer 2

Fallopian tube

Question 3

how is a blastocyst formed?

Answer 3

through division of zygote

Question 4

where does a blastocyst implant?

Answer 4

in the wall of the uterus-endometrium

Question 5

what are the two layers of the uterus?

Answer 5

outer muscular layer- myometrium

inner layer- endometrium

Question 6

what cells form the placenta during implantation?

Answer 6

trophoblasts

Question 7

what finger-like projects are found in the placenta?

Answer 7

placental villi-chorionic tissue

Question 8

what are the placenta villi surrounded by?

Answer 8

maternal blood

Question 9

how are metal blood and maternal blood seperated?

Answer 9

by capillary wall

Question 10

where does the maternal blood enter to exchange with fetal blood?

Answer 10

intervillus spaces of placenta villi

Question 11

do maternal and fetal blood mix?

Answer 11

no

Question 12

what systems does the placenta function as? and is this controlled by the foetus itself or the mother?

Answer 12

digestive, respiratory and kidneys and controlled by the mother

Question 13

what sort of placental diffusion occurs for things like water, electrolytes, 02 etc?

Answer 13

simple

Question 14

what sort of molecules require active transport?

Answer 14

glucose and amino acids

Question 15

how is cholesterol transported across placenta?

Answer 15

receptor-mediated endocytosis

Question 16

what may cause harm to the foetus if crossed via placenta?

Answer 16

drugs
alcohol
thalidamide
smoking
aids

Question 17

what else does the placenta act as?

Answer 17

endocrine gland

Question 18

what is the purpose of placental hormones?

Answer 18

to maintain the pregnancy

Question 19

what placental hormones are produced?

Answer 19

-hCG
-estrogen
-progesterone

Question 20

what hormone is detected by pregnancy tests?

Answer 20

hCG

Question 21

when does hCG rise in pregnancy?

Answer 21

early pregnancy then drops

Question 22

what is the purpose of the rise in hGC in early pregnancy?

Answer 22

prolongs the life span of corpus luteum

Question 23

what is the purpose of corpus luteum?

Answer 23

produces oestrogen and progesterone

Question 24

what stimulates testosterone release in males?

Answer 24

hCG

Question 25

how many weeks in hCG and corpus luteum needed?

Answer 25

around 10 weeks then the placenta can form oestrogen and progesterone on its own

Question 26

why is the placenta unable to produce oestrogen in early pregnancy?

Answer 26

it does not have the specific enzymes needed

Question 27

why is the placenta unable to produce progesterone in early pregnancy?

Answer 27

the placenta is too small to make enough

Question 28

how is oestrogen formed in the placenta?

Answer 28

cholesterol makes DHEA which forms oestrogen by adrenal cortex

Question 29

how is progesterone formed in the placenta?

Answer 29

from cholesterol

Question 30

what is the purpose of E and P in maintaining the pregnancy?

Answer 30

it allows the maintenance of thick endometrial tissue and stops menstruation

Question 31

what are the two purposes of estrogen?

Answer 31

-growth of myometrium
-growth of mammary milk ducts (milk ejects)

Question 32

what are the 3 purposes of progesterone?

Answer 32

-prevent miscarriage by preventing myometrium contractions
-stop vaginal contamination
-stimulates milk glands in breasts