Placentation, Gestation, and Parturition (3)

Question 1

What are the three final prepartum steps of repro?

Answer 1

formation of placenta, aquisition of endocrine function of placenta, and initiation of parturition

Question 2

define gestation

Answer 2

period of time female is pregnant

Question 3

what are euthrerian mammals?

Answer 3

mammals with placenta

Question 4

define implantation

Answer 4

attachment of placental membrane to endometrium

Question 5

what species is true implantation?

Answer 5

humans

Question 6

define placenta

Answer 6

organ of metabolic exchange between conceptus and dam

Question 7

what is the placenta responsible for?

Answer 7

maintain pregnancy and induction of parturition

Question 8

define parturition

Answer 8

giving birth

Question 9

what inititiates parturition?

Answer 9

the fetus

Question 10

what are the four events that occur during parturition?

Answer 10

myometrial contractions, dilation of cervix, expulsion of fetus, expulsion of extraembryonic membranes

Question 11

define conceptus

Answer 11

embryo and extraembryonic membranes

Question 12

define chorion villus

Answer 12

functional unit of fetal placenta

Question 13

what are the four types of placentas?

Answer 13

diffuse, zonary, discoid, cotyledonary

Question 14

what animal has a diffuse placenta?

Answer 14

pigs

Question 15

describe a diffuse placenta

Answer 15

velvet like surface with many closely spaced chorionic villi

Question 16

initial attachment of the diffuse placenta

Answer 16

day 12

Question 17

when is the diffuse placenta well established

Answer 17

day 18-20

Question 18

what animals have a zonary placenta?

Answer 18

dogs and cats

Question 19

describe a zonary placenta

Answer 19

pigmented ring on either end, important for iron transport

Question 20

transport zone equals…

Answer 20

poor vascularity

Question 21

what animals have a cotylledonary placenta?

Answer 21

ruminants

Question 22

describe a cotyledonary placenta

Answer 22

discrete button like structures called cotyledons

Question 23

how many cotyledons do sheep and cows have?

Answer 23

sheep have 90-100, cows have 70-100

Question 24

define placentome

Answer 24

point of interface between fetal cotyledon and maternal cotyledon that originates from the caruncles

Question 25

what placenta is essentially diffuse before attachment?

Answer 25

cotyledonary

Question 26

when does intial attachment occur for a cotyledonary placenta?

Answer 26

cow day 25, sheep day 16

Question 27

when is the cotyledonary placenta well established?

Answer 27

cow day 40, sheep day 30

Question 28

what are placentas classified by?

Answer 28

number of placental layers that separate fetal blood from the maternal blood

Question 29

how many layers is an epitheliochorial placenta?

Answer 29

6

Question 30

how many layers is an endotheliochorial placenta?

Answer 30

5

Question 31

how many layers is a hemochorial placenta?

Answer 31

3

Question 32

what do the hormones secreted by the placenta do?

Answer 32

stimulate ovarian function, amintain pregnancy, influence fetal growth, stimulate mammary function, and assist in parturiton

Question 33

how many stages are there to parturition?

Answer 33

3

Question 34

what are the three stages of parturition?

Answer 34

initation of conceptus, expulsion of fetus, and expulsion of fetal membranes

Question 35

what is secreted by the fetus during stress?

Answer 35

fetal cortisol

Question 36

what does fetal cortisol do?

Answer 36

causes enzymes to be made to convert progesterone to estradiol and causes placenta to produce prostaglandin

Question 37

when does the CL start to regress?

Answer 37

stage one during contractions

Question 38

what happens in stage two of parturition?

Answer 38

fetus is in the cervical canal

Question 39

what is relaxin?

Answer 39

glycoprotein produced by CL or placenta

Question 40

what does relaxin do?

Answer 40

stimulated by prostaglandin, softens cervix and relaxes pelvic ligaments

Question 41

what initiates secretions?

Answer 41

estradiol

Question 42

what does mucous do?

Answer 42

lubricates birth canal

Question 43

define dystocia

Answer 43

difficult birth

Question 44

when does dystocia typically occur?

Answer 44

during stage 2

Question 45

three causes of dystocia

Answer 45

large fetus, failure to fetal rotation, multiple birth in monotoccus species