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37 Cards in this Set
- Front
- Back
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What are the three layers associated with the bilaminar embryo and what does each become in the trilaminar embryo?
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Epiblast > ectoderm
Hypoblast > endoderm Trophoblast > extraembryonic ectoderm |
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T or F:
The trophoblast is considered extraembryonic ectoderm. |
True!
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Where does the mesoderm for the extraembryonic membrane derive from?
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Lateral plate mesoderm
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What are the four extraembryonic membranes? How many lamina is each comprised of?
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Yolk sac
Chorion Amnion Allantois All are comprised of 2 lamina |
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What two layers comprise the yolk sac? What vessels supply early nutrition from the yolk sac?
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endoderm and splanchnic mesoderm
vitelline vessels |
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What layers comprise the chorion? The amnion?
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Both are extraembryonic ectoderm (trophoblast) and somatic mesoderm
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What layers comprise the allantois?
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ectoderm and splanchnic mesoderm
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ID these extraembryonic layers in a developing embryo.
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A - Amnion
B - Chorion C - Allantois D - Yolk sac |
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What is the function of the chorion?
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Where exchange occurs (nutrition, waste, gas, water) Part of the fetal placenta
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What is the function of the amnion?
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contain secretions from primitive kidneys and gut
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What is the embryonic orign of the allantois? What developing organ is the allantois in connection with? What is this connection called?
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Endoderm and splanchnic mesoderm; diverticulum of embryonic hindgut; remains connected with urinary bladder via the urachus
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What are the fetal placental layers?
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Chorioallantoic membrane (endothelium - allantoic vessels, chorioallantoic CT, chorionic epithelium)
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What are the maternal placental layers?
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Endometrium (uterine epithelium, uterine connective tissue, endothelium)
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What are the two main layers of the placenta?
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Chorioallantoic membrane (fetal placental)
Endometrium (maternal placental layers) |
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T or F:
Most large domesticated species practice invasive apposition and implantation. |
False!
These are non-invasive. Carnivores, primates, and rodents are invasive. |
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What is the greatest number of placental layers between fetal and maternal blood?
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6 layers
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What are the histological divisions (by number of contact layers) of placenta types?
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Epitheliochorial
Syndesmochorial Endotheliochorial Hemochorial |
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What are the placental divisions by the sloughing or separation of endometrium at parturition?
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Adeciduate (non-deciduate)
Deciduate |
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T or F:
Fetal membranes of the placenta are always 3 layered. |
True!
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How many layers total in the epitheliochorial?
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6 layers
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What type of layered placenta is found in carnivores? In primates?
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Endotheliochorial
Hemochorial |
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How can the placenta be defined by shape? What are representative species of each?
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Diffuse (horse, pig)
Cotyledonary (Ruminants) Zonary (cat, dog) Discoid (primates, rodents) |
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T or F:
The only thing passed in a deciduate placenta is the fetal layers. |
False! Some uterine lining sloughs with deciduate.
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What are cotyledons in touch with in a cotyledonary placenta?
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Uterine caruncles
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ID these placenta types.
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A - Diffuse
B - Cotyledonary C - Discoid D - Zonary (single) E - Zonary (double) |
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How long does the yolk sac remain in the pig? The horse?
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12 days - pig
1/4 gestation - horse |
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Which type of placenta has all 6 layers intact?
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Epitheliochrorial (diffuse)
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T or F:
Piglets are born with their amniotic sac intact. |
False!
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Describe the horse placenta.
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Diffuse with microcotyledons;
Epitheliochorial (6 layers); adeciduate |
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T or F:
Horses are born with the amniotic sac intact. |
True!
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Describe the ruminant placenta.
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Cotyledonary, epithelialchorial (6 layers), semi-deciduate
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T or F:
Cows are born with the amniotic sac intact. |
False!
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What is the placental cotyledon + the uterine caruncle called?
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Placentome!!
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Describe the carnivore placenta.
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Zonary, endothelialchorial, deciduate
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T or F:
Pups are born with the amniotic sac intact. |
True!
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In what circumstance are freemartins a possibility? What hormone is responsible?
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Twin male and female ruminants sharing placental blood. Antimullerian hormone is responsible.
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What are two abnormalities of placentation? Which results in more fluid?
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Amnion hydrops (hydramnios)
Allantois hydrops (hydrallantois) - more fluid! |
