Embryology Akers Qs

Question 1

Blastocyst contains which 2 parts?

Answer 1

inner cell mass (ICM)

trophoblast

Question 2

Cells in ICM split into….

Answer 2

Epiblast- embryo proper

Hypoblast- primary endoderm- yolk sac

Question 3

What is the Primitive Streak?

Answer 3

first marker of craniocaudal axis
dorsal and caudal side of epiblast
cranial end becomes primitive node

Question 4

How do we turn the 2 layer disc into a 3 layer disc?

Answer 4

Gastrulation

cells migrate through primitive groove and form endoderm and mesoderm and ectoderm

Question 5

What is grastrulation?

Answer 5

process where 3 germ layers are formed through cell migration

Question 6

What are the 3 ways in which cells can migrate through the epiblast?

Answer 6

through the node
near the node
away from node

Question 7

Why is the method of migration in gastrulation important?

Answer 7

creates 3 different cell fates

Question 8

How is the neural tube formed?

Answer 8

Dorsal ectoderm becomes neural plate
lateral edges elevate and become neural folds
mid region depresses and becomes neural groove
neural folds fuse together

Question 9

What does the nonneural ectoderm become?

Answer 9

Skin

Question 10

What does the neural ectoderm become?

Answer 10

brain and spinal cord (CNS)

Question 11

What germ layer does the notochord come from?

Answer 11

Mesoderm

Question 12

What is neurulation?

Answer 12

formation of neural tube

Question 13

How do cells fuse during neurulation?

Answer 13

cells in middle of neural folds fuse first and zippers anteriorly and posteriorly at same time

Question 14

What are cranial and caudal neuropores?

Answer 14

openings at ends of neural tube

Question 15

How do birth defects or neural tube defects occur?

Answer 15

when the neuropores do not close correctly

Question 16

How should women avoid neural tube defects?

Answer 16

consume more folic acid

Question 17

What are the functions of the notochord?

Answer 17

defines body axis
provides rigidity to embryo
signaling center to induce neural fates
precursor for axial skeleton

Question 18

Which germ layer forms the neural crest?

Answer 18

ectoderm

Question 19

What are neural crest cells?

Answer 19

migratory cells that come from ectoderm and migrate throughout body to give rise to a number of cell fates

Question 20

What are the 4 regions of Mesoderm?

Answer 20

axial- notochord
paraxial mesoderm- somites
intermediate mesoderm- kidney/ gonads
lateral plate mesoderm- lining of organ cavities

Question 21

What are the derivatives of the endoderm?

Answer 21

gives rise to GI tract, epithelial lining of lung and trachea, liver, gall bladder, pancreas