Vocabulary - Gastrulation and neurulation

Question 1

the developmental process that establishes all three germ layers; defines embryonic symmetry; the beginning of morphogenesis (development of the body form); invagination

Answer 1

gastrulation

Question 2

process that brings subpopulations of cells into close proximity so they can interact and produce tissues and organs of the body

Answer 2

induction

Question 3

faint midline structure; found in epiblast near the caudal end of the bilaminar disc

Answer 3

primitive streak

Question 4

depression in the superior end of the primitive streak; future head forms here

Answer 4

primitive pit

Question 5

small elevation of epiblast that surrounds primitive pit

Answer 5

primitive nodes

Question 6

gives rise to the lining of the gut and gut derivates (new layer of cells derived from hypoblast)

Answer 6

definitive endoderm

Question 7

epiblast cells found in the space between epiblast and newly formed endoderm (third germ layer)

Answer 7

intraembryonic mesoderm

Question 8

serves as the basis for development of the axial skeleton (bones of the head and vertebral column)

Answer 8

notochord

Question 9

midline structure formed by the migration of the intraembryonic mesoderm (third germ layer)

Answer 9

notochord process

Question 10

mesoderm on either side of notochord

Answer 10

paraxial mesoderm

Question 11

mesoderm lateral to notochord

Answer 11

intermediate mesoderm

Question 12

mesoderm further lateral to notochord

Answer 12

lateral plate mesoderm

Question 13

two midline regions devoid of mesoderm

Answer 13

buccopharyngeal membrane and cloacal membrane

Question 14

rounded structures formed from paraxial mesoderm throughout 3rd and 4th week of development

Answer 14

somitomeres

Question 15

leftover somitomeres that flank notochord from occipital region to the embryonic tail; establish segmental organization of the body; gives rise to most of axial skeleton and voluntary muscles of neck, body wall, and limbs

Answer 15

somites

Question 16

subdivision of somite that differentiates into myogenic (muscle-producing) cells

Answer 16

myotomes

Question 17

subdivision of somite that differentiate into dermis of the neck, back, ventral/lateral trunk

Answer 17

dermatomes

Question 18

subdivision of somite that differentiate into the vertebrae

Answer 18

sclerotomes

Question 19

congenital abnormality resulting from the fusion of the lower extremity limb buds during development leading to “mermaid-like” appearance of fetus

Answer 19

sirenomelia

Question 20

a thickening in the epiblast along the midsagittal axis (cranial to the primitive pit)

Answer 20

neural plate

Question 21

process of folding occurring the 4th week of development

Answer 21

neurulation

Question 22

congenital defect resulting from underdevelopment of vertebral arches and lack of fusion along the dorsal midline leading to an open vertebral canal.

incidence is 1 in 600.

Answer 22

spina bifida

Question 23

“drag” the blastocyst into the “belly” of the endometrium; enters through coagulation plug

Answer 23

syncytiotrophoblast

Question 24

what 2 cell layers does the inner cell mass give rise to?

Answer 24

hypoblast (primary endoderm) and epiblast (primary ectoderm)