Q1 Exam 1 Embryology ONLY

Question 1

secondary oocyte

Answer 1

egg prior to fertilization, after first division (has first polar body)

Question 2

zona pellucida

Answer 2

the exterior glycoprotein coat of a secondary oocyte

Question 3

follicular cells

Answer 3

cells surrounding a secondary oocyte in layers

Question 4

corona radiata

Answer 4

zona pellucida + follicular cells around secondary oocyte

Question 5

acrosome cap

Answer 5

specialized lysosome that allows sperm into cell, but cannot fertilize until it is gone (capacitation)

Question 6

zona reaction

Answer 6

once sperm is in oocyte, no other sperms can enter, and the corona radiata has disappeared

Question 7

pronucleus

Answer 7

female forms from second meiotic division, male forms from sperm

Question 8

zygote

Answer 8

forms from fertilized oocyte when pronuclei merge

Question 9

morula

Answer 9

a superficial layer around a central core of cells

Question 10

blastomere

Answer 10

new embryonic cell, totipotent

Question 11

trophoblast

Answer 11

usually external layer of cells

Question 12

embryoblast

Answer 12

inner cell mass

Question 13

blastocystic cavity

Answer 13

formed by secretions from blastocysts

Question 14

animal pole

Answer 14

side of the conceptus closest to the embryoblast

Question 15

vegetal pole

Answer 15

side of the conceptus farthest from the embryoblast

Question 16

rauber’s layer

Answer 16

layer of trophoblast that will disintegrate to form the epiblast

Question 17

hypoblast

Answer 17

cells formed to enclose the exocoelomic cavity

Question 18

primitive yolk sac

Answer 18

sac formed when the hypoblast finishes joining to enclose the exocoelomic cavity

Question 19

epiblast

Answer 19

forms tight junctions at the animal pole of conceptus, replaces rauber’s layer

Question 20

embryonic disc

Answer 20

bilaminar disc of epiblast and adjacent hypoblast

Question 21

extraembryonic mesoderm

Answer 21

could be somatic (everything else) or visceral (surrounds hypoblast)

Question 22

definitive yolk sac

Answer 22

formed from primitive yolk sac when extraembryonic mesoderm is formed

Question 23

amniotic membrane

Answer 23

formed from the epiblast to create a second cavity, amniotic sac

Question 24

primitive streak

Answer 24

appears on the dorsal aspect of the of the embryonic disc, reaching into the center from the connecting stalk attachment point

Question 25

prechordal plate

Answer 25

across the embryonic disc from the primitive streak, forms the mouth

Question 26

three germ layers and from whence they are derived

Answer 26

ectoderm
mesoderm
endoderm
ALL TECHNICALLY ORIGINATE IN EPIBLAST

Question 27

mesenchymal cells

Answer 27

migrates through the mesoderm from the primitive pit

Question 28

destiny of the endoderm

Answer 28

lining of gut/lungs a little

Question 29

paraxial mesoderm destiny

Answer 29

somites, including dermatome, myotome, and sclerotome

Question 30

intermediate mesoderm destiny

Answer 30

gonads and portions of urogenitalia

Question 31

lateral plate mesoderm destiny

Answer 31

somatic layer: body wall structures
visceral layer: smooth muscle of gut

Question 32

endoderm destiny

Answer 32

lining of the GI tract

Question 33

allantois

Answer 33

the sac that eventually swallows the extraembryonic coelom

Question 34

chorion

Answer 34

former trophoblast, changes at folding I think

Question 35

choriovitelline membrane

Answer 35

the bottom of the definitive yolk sac fuses with the chorion, extraembryonic mesoderm (makes blood vessels) between

Question 36

epitheliochorial placenta

Answer 36

horses specific (chorionic girdle and endometrial cups are microcotyledons)

Question 37

synepitheliochorial placenta

Answer 37

cattle, placentomes = caruncle and cotyledon

Question 38

endotheliochorial placenta

Answer 38

dogs and cats, zonary placentation, haemophagus organ