Histo On Your
Nerves
SSN Histology
October 26th, 2004
Missy Walker, maw2106@columbia.edu
So Young Kim, sk2298@columbia.edu
So what’s in a nerve?
Dendrite
Axon Terminal
Nucleus of myelinproducing cells
Node of Ranvier
Axon
MyelinProducing Cell Axon Hillock
Perikaryon
Axon vs. Dendrite
Axon
NO Synthetic
Machinery!
Dendrite
Nervous System Classifications
Nervous System
CNS
Spinal Cord
Cerebellum
PNS
Cerebral Cx
ANS
( Ganglia)
Somatic
Enteric
(Peripheral Nerve)
Spinal Cord
Spinal Cord: White Matter
Myelin Production in CNS
Oligodendrocytes
Spinal Cord Gray Matter
Spinal Cord
Cajal’s Silver
Meninges
Astrocytes
No collagen in the CNS!!!
Brain
Cerebellum
Cerebellum
Purkinje Cell
Cerebral Cortex
Cerebral Cortex
Cerebellum vs. Cerebral Cx
Cerebellum vs. Cerebral Cortex
Pyramidal Cells vs. Spinal Cord Gray
Matter
Peripheral Nervous System (PNS)
Nervous tissue outside of the brain and spinal cord
Somatic Nervous System
Autonomic Nervous System
• Innervates skeletal muscle
• Innervates smooth muscle
and glands
• For organ function and
regulation
• Cell bodies in CNS and
PNS
• For conscious movement
• Cell bodies in CNS
Sympathetic &
Parasympathetic
ANS - Ganglia
Sympathetic GANGLIA in thorax
contain:
• neuronal cell bodies
• satellite cells (support cells of
the neuron)
Synapses occur
• Presynaptic fibers myelinated
• Postsynaptic fibers
unmyelinated
Enteric NS - Ganglia
Myenteric plexus in ENS
• Within Smooth Muscle of
Gut
• NO Collagen (as in CNS)
• Glial cells (no Schwann
cells)
• Nuclei are euchromatic
• Gut has “mind of its own”
ENS Ganglion vs ANS Ganglion
Cross section of nerve
Organization by
Connective Tissues
• Endoneurium
collagen
fibers associated with individual
neurons -Schwann cells within
• Perineurium layer(s) of
connective tissue cells, create
fascicles
• Epineurium dense cnxtive
tissue binding fascicles into a
bundle
Peripheral nerve
• Epineurium
• Perineurium
• Endoneurium
Periph nerve
- longitudinal section
• Endoneurium
• Perineurium
• Epineurium
Longitudinal Section – Cajal stain
Peripheral Nerve – High Power (Cajal)
• Nodes of Ranvier
• Neurilemma
(cytoplasm of
Schwann cells)
• What’s the
black?
Peripheral Nerve – High Power (H&E)
What’s the purple?
What’s the white?
Cross Section – Peripheral Nerve
• What’s the purple?
Peripheral Nerve
• Why is this a Nerve, not a Ganglion?
Key Points for PNS
• Ganglia
– Contain cell bodies for motor ANS
– Satellite cells are the supporting cell bodies (not glial,
Schwann, or others of CNS)
• Peripheral Nerves
– Schwann cells make mylin sheath
– Node of Ranvier / saltatory conduction / Na channels
– Endoneurium around neurons, which form fascicles
– Perineurium around fascicles, which form bundles
– Epineurium around bundles
Same or different?
Same or different?
What are these?
Questions 1 & 2. . .
A
B
Question 3. . .
Figure A
Figure B
Question 4. . .
Question 5. . .
Question 6. . .