Nervous system

Lecture 1

NERVOUS SYSTEM
Dr. Thana Al-Khishali

NERVOUS SYSTEM

Anatomy
Physiology
Histology
Neurons
Glial cells
Central Nervous System
CSF, BBB, Meninges
Peripheral Nervous System
NF, Ganglia
Neural Plasticity and Regeneration

Nervous System

Divided Anatomically into

Central Peripheral
CNS PNS
Brain and Spinal Cord Nerves (motor and sensory)
Ganglia
Nerve Endings
Both CNS and PNS consist of :
Nerve cells (Neuron) and Glial cells

Components of the Nervous System

Peripheral Nervous System
The Nervous System

Nervous Tissue as an integrated communications network :

CREATES

ANALYZES

IDENTIFIES

INTEGRATES

The information

Organization of the Nervous System

Central nervous system
Brain & spinal cord.
Integrative & control centers.
Peripheral nervous system
Cranial & spinal nerves.
Communicates between CNS and rest of body.
Sensory (afferent division)
Impulse from receptor to CNS.
Motor (efferent) division
Impulse from CNS to effector.


Autonomic nervous
System
-to visceral organs.
Somatic nervous
System
-to muscles
Sympathetic Division
“Excites”
Parasympathetic Division
“Retards”

The Neuron

Multipolar,
Bipolar , and
Unipolar (pseudounipolar)

THE NEURON

• Motor
• Sensory
• Internuncial


Classification of Neurons
based on direction of impulse
Afferent (sensory) neurons – conduct impulses towards the CNS
Efferent (motor) neurons – conduct impulses away from the CNS
Internuncial (association) Neurons –carry impulses between neurons within the CNS (may be either sensory or motor)

Structural Classification of Neurons

Unipolar Neuron

Bipolar Neuron

Multipolar Neuron

Pyramidal Cells (slide #29)

Neuron Structure – Cell Body (= Soma)

Neuron Structure – Cell Body (= Soma)

contains the usual cellular organelles
synthesis & metabolism occurs primarily in the soma
the outer cell membrane contains the receptors for incoming information (stimuli)
most cell bodies are located within the CNS
clusters of neuron cell bodies in the CNS are called nuclei
clusters of neuron cell bodies in the PNS are called ganglia

Histology of Nervous Tissue

Parts of a Neuron

Schematic diagram of a neuron

TEM of Nerve Cell Body and Axon
Nu = nucleus

Ax = Axon

Fi = neurofilaments; Re = RER; Go = golgi; Mi = Mitochondria

Nerve Cell Body with dark staining Nissl

Mitochondria M

Rough Endoplasmic Reticulum rER
Nucleus N
Golgi Apparatus G
Microtubules T
Synapse
Terminal bouton TB
Ultrastructure of The Neuron (Electron Microscope) EM
Lysosome L

A Review of the Neuron Structure

Relationship of the 4 parts of a neuron (dendrites, cell body, axon, and synaptic terminals);
- the functional activities of each part
- the normal direction of action potential conduction

Pyramidal Cells, 2

Purkinje Cells, 2

Purkinje Cells, 3

Purkinje Cells, 4

cytoskeleton stain

Neurons with different staining methods

Axon A
Dendrite D
Neuron N
Terminal bouton B