Development of the peripheral nervous system Flashcards
(63 cards)
1
Q
Central Nervous System (CNS)
A
– Brain
– Spinal Cord
2
Q
Peripheral Nervous System (PNS)
A
– Cranial nerves – Spinal nerves – Ganglia – Enteric plexus – Sensory receptors
3
Q
gray matter
A
- location of cell bodies and neurons
- unmyelinated
4
Q
dorsal (posterior) horn
A
sensory
5
Q
lateral horn
A
autonomics
6
Q
anterior (ventral horn)
A
motor
7
Q
white matter
A
- location of axons
- myelinated
8
Q
dorsal (posterior) funiculus
A
sensory
9
Q
lateral funiculus
A
sensory and motor
10
Q
anterior (ventral) funiculus
A
- primarly motor
11
Q
what does the sulcus limitans separate?
A
alar plate from the basal plate
12
Q
alar plate
A
sensory neurons that stay in CNS
13
Q
basal plate
A
- motor neurons
- preganglionic neurons for ANS and neurons to musle
14
Q
central canal
A
connected to ventricular system in brain
15
Q
ventricular zone
A
-next to central canal
16
Q
cells of ventricular zone
A
germinal or ventricular cells (stem cells)
- ependymoblast
- ependyma cell
- choroid plexus cells (makes CSF)
17
Q
intermediate zone
A
-gray matter
18
Q
intermediate zone cells
A
- astrocyte
- neuron
19
Q
marginal zone
A
-white matter
20
Q
marginal zone cells
A
- axon
- oligodendrocyte
21
Q
what layer do mesenchymal and microglial cells come from?
A
mesoderm
22
Q
position of spinal cord in newborns
A
L2 or L3
23
Q
position of spinal cord in adults
A
L1 or L2
24
Q
neural crest cells
A
give rise to
spinal ganglion cells and
sensory neurons in the
periphery
25
how is spinal cord formed
Dorsal (sensory) and ventral
(motor) region dependent on
concentration gradients
26
what does high BMP activate?
activate PAX3
and 7 = sensory neuron
differentiation = alar plate
27
what does high SHH activate?
NKX2.2 and NKX6.1 = ventral
| neuron formation = basal plate
28
how are ventral motor neurons formed?
Just dorsal there are slightly lower
SSH and higher levels of BMP
activate NKX6.1 and PAX6
29
if there are high amount of BMP how will spinal cord be patterned?
dorsally
30
if there are high amount of SHH how will spinal cord be patterned?
ventrally
31
what forms the PNS
neural crest and ectodermal placode (from ectoderm)
32
what are cells that develop from neural tube?
- motor neurons
| - pre ganglionic autonomic neurons (in lateral horn)
33
what are cells that develop from neural crest?
```
– Neurons of dorsal root
ganglia
– Sensory ganglia of cranial
nerves
– Schwann cells
– Sympathetic ganglia
– Parasympathetic ganglia
```
34
Dorsal root (sensory)
- spinal ganglion (dorsal root ganglion)
| - neural crest
35
ventral root (motor)
-neuroectoderm
36
spinal nerve
mixed
37
dorsal ramus
- mixed
- motor to dorsal muscles (true muscles of back= epiaxial)
- sensory to dorsal integument
38
ventral ramus (mixed)
– Sensory to integument of
same regions
-motor to limbs, lateral and ventral body wall (hypomere/hypaxial)
39
ramus communicantes
-motor and sensory to viscera
40
(General somatic efferent):
somatic muscle
| -neuroectoderm
41
GVE (General visceral efferent)
-autonomics to smooth and
cardiac muscle and glands
-neuroectoderm
42
SVE (Branchial or Special visceral efferent):
muscles derived
from the pharyngeal arches
-neuroectoderm
43
GSA (General somatic afferent)
-sensory in the skin, joint
capsule, tendon, muscle
-ectoderm or from mesoderm adjacent to ectoderm
-neural crest cells
44
GVA (General visceral afferent)
:sensory of visceral structures
– Endoderm or mesoderm adjacent to endoderm
-neural crest
45
SSA (Special somatic afferent):
hearing, balance and sight
46
SVA (Special visceral afferent):
-taste and smell
47
efferent somatic
Motor fibers
ending on
skeletal muscle
-neuroectoderm
48
efferent visceral
```
Motor fibers
ending about
autonomic
ganglion cells
which, in turn
control smooth
muscle, cardiac
muscle and
glands
-neuroectoderm
```
49
Afferent
| sensory
```
Sensory fibers
originating
chiefly from
integument
-neural crest cells
```
50
afferent (sensory)
| Visceral:
Sensory fibers
originating
from viscera
-neural crest cells
51
Autonomic Nervous System (ANS)
• Innervation of smooth muscle, cardiac muscle and
| glands.
52
what are two motor paths have ANS
– Sympathetic
| – Parasympathetic
53
formation of ganglia and post-ganglion
| cells. (ANS)
neural crest
54
formation of the pre-ganglion cells(ANS)
neuroectoderm
55
Sympathetic
Located in the spinal cord in the thoraco-lumbar
| region (T1-L2)
56
preganglionic (sympathetic)
from spinal cord to sympathetic ganglia
- neuroectoderm
- short myelinated
57
postganglionic (sympathetic)
from ganglia to viscera
- neural crest
- long, not myelinated
58
Parasympathetic
Cranial-sacral region – Cranial: primarily cranial nerves
| – Sacral: 2nd to 4th sacral spinal nerves (GVE)
59
Preganglionic (parasympathetic)
- from spinal cord to sympathetic ganglia
- neuroectoderm
- long and myelinated
60
postganglionic (parasympathetic)
- from ganglia to viscera
- neural crest cells
- short and unmyelinated
61
how many cranial ganglia are there?
4
62
what myelinates the CNS
- oligodendrocytes
- from neuroectoderm
- starts in lower brain stem first
- 6 months through puberty
63
what myelinates the PNS
- schwann cells
- neural crest ells
- motor roots myelinated before sensory roots
- 4th month
