Histology of the Nervous System
Nervous Tissue
Nervous
Nervous System
System
stimulus
stimulusand
andreaction
reaction
environment
animal
animal
organism
organism
Nervous system
stimulus
receptor
sensory
neuron
Interneuron
Motor
neuron
reaction
effector
Nervous System
• Central Nervous System
brain, spinal cord: nervous tissue
meninges, choroid plexus: connective tissue
• Peripheral Nervous System
nerve, ganglion, nerve plexus:
nervous tissue and connective tissue
cf. Somatic vs Autonomic Nervous System
Enteric Nervous System
Nervous Tissue
Cellular Elements
y Neuron (Nerve Cell)
y Neuroglial Cells
central neurglia
astrocyte, oligodendrocyte, microglia and
ependymal cell
peripheral neuroglia
Schwann cell in nerve and ganglion
satellite (capsular) cell in ganglion
Intercellular Substance: extremly scarse
Neuron
Neuronal Morphology
Neuronal Cell Body (Soma)
y Nucleus
y Perikaryon
Neuronal Processes
y Axon
y Dendrites
cf. Diversity of Neuronal Size and Morphology
Diversity of
Neuronal
Morphology
Morphology of
Typical Motor Neuron
1. nucleus
2. perikaryon
3. cell body
4. axon
5. dendrite
6. Nissl body
7. axon hillock
8. myelin sheath
9. oligodendrocyte
10. Schwann cell
11. skeletal muscle cell
12. neuromuscular junction
Neuron
Neuronal Function
Communication
Receptor - Neuron - Effector
- Excitability (Irritability)
- Conductivity
through membrane in intraneuronal conduction
via synapse in interneuronal conduction
neurotransmitters
Neuronal Cell Body (Soma)
NUCLEUS
y Chromatin Pattern: Euchromatic
euchromatin >>> heterochromatin
active mRNA transcription
cf. Barr body (facultative heterochromatin)
inactive X chromosome in female
y Conspicuous Nucleolus
NOR (nucleolar organizing region)
active rRNA transcription -- ribosome
NB: neuronal cell body
NL: nucleolus
NS: Nissl substance
BB: Barr body
Murray
Llewellyn
Barr
1908-1995
Neuronal Cell Body (Soma)
Cytoplasmic Organelles
y Nissl substance: rER
abundant, parallally arranged rER cisterna
active site of protein (polypeptide) synthesis
- transport vesicle
y Golgi complex
complex of perinuclear Golgi substance
glycosylation, sulfation & phosphorylation
packing and condensation protein to transport
Camilio Golgi
(1843-1926)
Golgi apparatus
Golgi method
(Golgi’s metallic impregnation)
Golgi type I & II cell
Golgi tendon organ
Golgi-Mazzoni corpuscle
Neuronal Cell Body (Soma)
Protein Synthesizing Assembly
y Euchromatic Nucleus
------- mRNA transcription
y Prominent Nucleolus
------- rRNA (ribosome) synthesis
y Nissl substance: rER
------- polypeptide chain
y Golgi complex ----- destined to transport
- no protein synthesizing assembly in axon
- neurotransmitters, enzymes, membrane proteins
- transport via axonal (axoplasmic) transport