Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Animal Production > Placenta > Flashcards

Placenta Flashcards

1
Q

Placenta

A

-composed of fetal and maternal tissues
>Chorion and allantois (Chorioallantoic- major in eutherians)
>Chorion and yolk sac (choriovitelline- most domestic animals)
>Endometrium/Decidua

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Chorionic villi

A

-Major functional units

-projections on the surface of the chorion that closely interact with maternal tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the individual cells of the villi?

A

trophoblast

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Where do differences occur between placentas?

A

-endocrinological
-immunological
-metabolic communication between mother and fetus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Function of placenta during pregnancy

A

-transfer O2, CO2
-fetal nutrition
-excretory fucntions (water balance, pH regulation)
-hormone/enzyme production
-immunological functions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Placental transport

A

-Diffusion
-facilitated diffucion
-active transport
-receptor-mediated endocytosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Diffusion in placenta

A

Gases, simple molecules, water movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Facilitated diffusion in placenta

A

glucose moves with a chemical gradient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Active transport in placenta

A

-essential amino acids, water soluble vitamins, Na, K, Ca
**maintain higher concentrations in fetus than mother

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Receptor-mediated endocytosis

A

-immunoglobulins (IgG), some protein, fat, viruses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Pig and Horse placenta

A

-Diffuse- chorionic villi located over the entire uterine luminal epithelium

-Epitheliochorial- epithelium of chorionic villi and uterine luminal epithelium are intact

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Types of nutrition of placenta

A

-Hemotrophic

-Histotrophic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Hemotrophic nutrition

A

-movement of substances from maternal to fetal circulation via crossing of intervening layers of cells

Eg. active transport, facilitated diffusion

**All placenta types do this

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Histotrophic nutrition

A

Uptake of uterine gland secretions, tissue debris, maternal blood cells via pinocytosis or endocytosis

-occurs in varied placentae but especially in epitheliochorial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Areolae

A

-Top: columnar trophoblast capable of endocytosis and pinocytosis and breakdown of absorbed materials for transfer to fetal capillaries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What nutrients are taken up by Areolae?

A

-proteins
-Uteroferrin (bi-iron protein)
-vitamins
-minerals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What form of nutrition is easily accomplished with areolae?

A

Histotrophic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Microcotyledons of mare

A

-both maternal and fetal circulation very close together
>use hemotrophic nutrition

-has smaller areolae linked with microcotyledons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Endometrial cups

A

-derived from a narrow band of thick trophoblast that develop around the fetus (chorionic girdle ~day 25)

-Day 40- girdle peels off fetal membranes and trophoblast invade the endometrium to form the cups and produce eCG

-Day 70- destroyed due to maternal immune attack

20
Q

Chorionic girdle attachment

A

The first attachment of the chorionic epithelium to the uterine epithelium prior to the development of the microcotyledons

21
Q

eCG (equine chorionic gonadotropin)

A

-A gonadotropin of placenta

-provides a stimulus for maintenance of the primary CL in the ovary formed from primary follicle AND stimulates formation and maintenance of accessory CL’s that produce more progesterone during pregnancy

22
Q

eCG levels throughout pregnancy

A

-Glycoprotein is detected around 38-42 days

-Max levels occur 60-70 days and then decline with little or no detection by 150 days of gestation (due to endometrial cups being attacked by maternal immune system)

23
Q

Accessory CL’s

A

Develop 40-60 days gestation from ovulation, and luteinization of anovulatory follicles

-Receives eCG signal (LH and FSH like activity)

24
Q

eCG function

A

-Provides signal for formation of the accessory CLs

-Regulates luteal steroidogenesis

25
eCG stimulation of primary and accessory CLs
-increased circulating progesterone concentrations which plateau between 50-140 days of gestation then decrease -from 180-200 days, concentrations will be very low until day 300 when progesterone rapidly increases again for parturition
26
Cow, sheep, goat placenta
Cotyledonary and Syn-epitheliochorial
27
Cotyledonary
-chorionic vascularized villous trophoblasts and uterine endometrial structures = caruncles come together= "spot weld" Caruncles and cotyledons combine to be placentomes
28
Syn-epitheliochorial
Some trophoblast cells fuse together into binucleate giant trophoblast cells (BNGC) >BNGC migrate into the uterine epithelium where they can fuse with maternal cells into trinucleate giant trophoblast
29
Pregnancy Associated glycoproteins
**also called pregnancy specific proteins B (PSP-Bs) -large groups of aspartic proteinases (cleave proteins at aspartic residues) -unclear function- likely process or cleave growth factors and other maternally released factors at trophoblast-uterine interface
30
Dog and cat placenta
-zonary -endotheliochorial
31
Zonary
An invasive band of the chorion surrounds the middle of the fetus
32
Endotheliochorial
-trophoblasts move through uterine epithelium, stroma, and are in contact with maternal endothelia
33
Rats, mice, higher primates placenta
-discoid -hemochorial
34
Discoid
-a disk like structure of chorion interacting with maternal tissue
35
Hemochorial
-highly invasive trophoblast pass through the maternal uterine epithelium, stroma, and endothelium of maternal vasculature becoming directly in contact with maternal blood
36
Passive immunity transfer through placenta
-occurs in primates, rodents, dogs, cats -due to slight (endotheliochorial) or considerable (hemochorial) trophoblast invasion with maternal blood **only IgG is transferred via receptor mediated endocytosis because Fc receptor on trophoblasts
37
IgG transfer in horses, pigs, ruminants
**does not occur due to extra layers in the maternal-fetal interface -IgGs passed only via colostrum in there species
38
Placenta secreting progesterone
-Placenta of all domestic species can produce steroids like estrogen and progesterone EXCEPT DOG
39
Progesterone role in pregnancy
Progesterone NEEDED for pregnancy. >Horse has 5alpha-dihydroprogesterone as potent progesterone >mostly luteal progesterone synthesis (goat, pig, and only in dog) >Bovine- an intermediate between luteal and placental production
40
Placental steroidogenesis
Two pathways 1.Delta 4 pathway= progestogens 2. Delta 5 pathway= androgens and estrogens
41
Delta 4 pathway
Cholesterol -> Pregnenolone (and 3B-HSD) -> progesterone
42
Delta 5 pathway
Dehydroepiandrosterone -> Androstenedione (and P450aromatase enzyme) -> Oestrone <-> Oestradiol
43
Placental steroidogenesis in cow and ewe
Use both spatial and temporal compartmentalization 1. Uninucleate Trophoblast cell (UTC)-use cholesterol to produce pregnenolone and Dehydroepiandrosterone 2. Trophoblast Giant Cell (binucleate and trinucleate)- use products of UTC to make progesterone, androstenedione, and oestrone
44
Estrogens
-important product of placenta -many different types (estradiol, estrone, equine specific equilin and equilenin
45
Mare estrogen formation by placenta
-Placenta cannot make steroids by scratch, needs precursors from fetal gonads
46
Relaxin
A small polypeptide hormone of the insulin superfamily -7 ID'd relaxin peptides; many GPC receptors -produced by many different tissues
47
Relaxin secretion
Mares: placenta Humans, dogs, cats: trophoblasts Pig: CL, not placenta Ruminants: not discovered yet

Animal Production (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions