Development of PNS

Question 1

What divides the neural tube into dorsal and ventral regions

Answer 1

Sulcus limitans

Question 2

What type of cells do not come from the neuroepithelium

Answer 2

Mesenchymal cells which form microglial cells

Question 3

Neuroepithelium forms what 3 main types

Answer 3

Apolar neuroblast - goes to bipolar, unipolar, and then to typical nerve

Glioblast - goes to astroblast then proplasmic astrocyte and fibrous asctrocyte OR glioblast goes to oligodendroblast and then oligodendrocyte

Ependyma - the cells that makes CSF which are preferred

Question 4

What are the different layers of the neural tubes from closest to lumen to most distant

Answer 4

Ventricular zone - stem cells undergoing mitosis

Mantle/intermediate zone - migrating cells that undergo differentiation into neurons or glia and they extend their neurons farther away

Marginal zone - mostly axons that will eventually be myelinated

Question 5

What plate forms what will be the dorsal side of the cord

Answer 5

Alar column and roof plate

Question 6

What plate forms the ventral side of the cord

Answer 6

Basal column and floor plate

Question 7

What causes motor and sensory neurons to form

Answer 7

Increased SHH is motor; decreased is sensory

Question 8

What does SHH activate downstream

Answer 8

NKX2.2 and NKX6.1

Question 9

What counteracts SHH gradient

Answer 9

BMP and TGFb

Question 10

What does BMP4 activate

Answer 10

PAX3 and 7

Question 11

What forms first in the spinal cord, motor neurons or sensory neurons

Answer 11

Motor

Question 12

Sympathetic ANS intermediolateral columns are where

Answer 12

T1-L3

Question 13

What plate undergoes differentiation to become interomediolateral columns

Answer 13

Dorsal most basal plate

Question 14

What do intermediolateral columns eventually form

Answer 14

Lateral horns

Question 15

Intermediolateral columns in s2-s4 make up what

Answer 15

The parasympathetic division of ANS

Question 16

Ectodermal placodes give rise to

Answer 16

The senses

Question 17

In the trunk, NCC give rise to

Answer 17

Sensory neurons in DRG, schwann cells, sympathetic ganglion, enteric nervous system (digestion)

Question 18

Axons exiting through the ventral horn pass through the cranial sclerotome and form

Answer 18

The ventral root

Question 19

What are the components of the spinal nerve

Answer 19

Dorsal root, ventral root, and visceral MN from lateral horn

Question 20

How many neurons are typically in an autonomic activation? Somatic

Answer 20

2, 1

Question 21

Which has a wider net of neurons activating it, sympathetic or parasympathetic

Answer 21

Sympathetic, there are 2 neurons involved

Question 22

What do preganglionic neurons come from

Answer 22

Neuroectoderm

Question 23

When do the preganglionic neurons form

Answer 23

Week 5

Question 24

What myelinates CNS and when? PNS?

Answer 24

Oligodendrocytes, 6 months to puberty, older tracts first

Schwann cells
Motor before sensory, 4th month