Ch. 8

Question 1

When is the pre-embryonic and what happens??

Answer 1

conception to 2nd week, cluster of cells become suspend by what will be the placenta

Question 2

When is the embryonic and what happens??

Answer 2

2nd-8th week, 3 layers develop, ectoderm, mesoderm, endoderm

Question 3

ectoderm

Answer 3

nervous system, epiderm, sensory

Question 4

mesoderm

Answer 4

dermis, Mm, skeleton, circulatory

Question 5

endoderm

Answer 5

gut, liver, pancreas and respiratory system

Question 6

When is the fetal and what happens??

Answer 6

8th week to birth, migration of skin and Mm
top of neural tube swells - head
cells multiply

Question 7

When does neural tube development occur?

Answer 7

Days 18-26, Embryonic stage

Question 8

Describe neural tube development.

Answer 8

Flat surface rolls and becomes tube
become neural tube and crest
cells lay aside which are dorsal root ganglion

Question 9

What forms inside neural tube

Answer 9

horns - inner circle- mantle-multipolar -motor

columns - outer - marginal - myelin - oligiodendrocytes

Question 10

what begins to occur at mesoderm?

Answer 10

31 spinal nerves on either side

Question 11

What forms from the somite?

Answer 11

sclerotome, myotome, dermatome which drag axon from neural tube to desired location