Development of Peripheral Nervous System Flashcards Preview

Anatomy Exam 1 > Development of Peripheral Nervous System > Flashcards

Flashcards in Development of Peripheral Nervous System Deck (22)
Loading flashcards...
1
Q

The Peripheral Nervous System consist of what?

A

12 Cranial Nerves

Spinal Nerves

Ganglia

Enteric plexus - inervates gut

Sensory Receptors

2
Q

Discribe the order of Grey Matter

A

Dorsal or posterior horn is Sensory

The lateral horn is autonomics

The anterior or ventral horn is motor

3
Q

Describe the formation of the spinal cord

Where does it form?

What is the difference between Alar and Baslar plates?

A

Alar plate is for sensory neurons

Baslar plate is for motor neurons + presynaptic neurons for autonomics

They are seperated by the Sulcus limitans

4
Q

1st order sensory neurons come from where?

2nd and 3rd?

A

Embryonic Crest

Alar Plate

5
Q

Stem cells in the Neural Canal produce what cells in the Ventricular Zone?

A

Ependmyoblasts

Ependymal cells - Line the ventricals and Central Canal

Choroid plexus cells - Makes CSF

6
Q

Stem cells in the Neural Canal produce what cells in the Intermediate Zone?

A

Neurons

Astrocytes - Structural cells that regulate environment

7
Q

Stem cells in the Neural Canal produce what cells in the Marginal cells?

A

Mylenated axons (Oligodentrocytes)

8
Q

Where do Microglial cells come from in the CNS?

What do they do?

A

Monocytes

Phagocytose debris and dead cells

9
Q

Where is the end of the spinal cord found in adults vs infants?

A

L1 or L2 for adults

L2 or L3 for new borns

10
Q

What cells do neuro crest cells give rise to?

A

Spinal Ganglion and Sensory Neurons in the periphery

Schwann Cells

11
Q

How is the alar and basal plate signaled to form the spinal cord

A

By a gradient

High BMP from Roof plate on alar side activate PAX3 and PAX7 to generate its differentiation

High Shh from floor plate and notocord levels on basal side activate NXK2.2 and NKX6.1 to promote

(just dorsal there are slightly lower Shh and higher BMP, this allows for ventral motor neurons)

12
Q

Where does the development of the PNS come from

A

The neuro crest cells and the ectodermal placodes (from ectoderm)?

13
Q

Specific cells that develop from the neural tube (neuro ectoderm).

A

motor neurons - located in ventral horn

pre-ganglionic autonomic neurons - located in lateral horn

14
Q

Specific cells from neurocrest.

A

Neurons of dorsal root ganglia

Sensory ganglia of cranial nerves

Schwann Cells

Sympathetic and Parasympathetic neurons

15
Q

Decribe the classifications of motor neurons derived from the neuroectoderm.

A

GSE (general somatic efferent) - Somatic muscle - somite derived

GVE (general visceral efferent) - autonomics to smooth and cardiac muscles and glands

SVE (Brachial or Special visceral efferent) - muscles derived from pharyngeal arches

16
Q

Describe the classifications of motor neurons derived from the neurocrest.

A
  • *GVA (General visceral afferent)**: sensory of visceral structures – Ectoderm
  • *SSA (Special somatic afferent):** hearing, balance and sight – Endoderm

SVA (Special visceral afferent): taste and smell: chemical
senses

GSA (General somatic afferent): sensory in the skin, joint
capsule, tendon, muscle

17
Q

The parasympathetic or sympathetic nervous sytem are involved in a two cell link system. Describe this.

What is the difference?

A

Short peganglionic nerves from spinal cord which are myelinated send signals to long postganglionic nerves which are not

Sympathetic = short to long

Parasympathetic = long to short

18
Q

Sympathetics come from where?

A

The lateral horns of the spinal cord. Are found in the T1 to L2.

19
Q

Parasympathetics come from where?

A

Cranial Nerves III, XII, IX, X

Sacral 2nd to 4th (GVE)

Ganglia usually found in viscera or in the 4 cranial ganglia

20
Q

Describe whether the dorsal and ventral root are efferent or afferent

A

Dorsal = efferent

Ventral = afferent

21
Q

Motor neurons are derived from what?

A

The neural ectoderm

(often long axons)

22
Q

Sensory Neurons are derived from what?

A

The neura crest