Nervous system
Central nervous system (C.N.S.)
Prepheral nervous system
(P.N.S.)
Type of nervous system
Organization of the Nervous System
Figure 8-1: Organization of the nervous system
P.N.S.
Nerve :Nerve Fiber: Axons + Sheathe cells
(Schwan cells, oligodendrocyte )
Ganglion :
Perikaryons + dendrites + axons (first portion)
Satellite cells
Cells of nervous system
NeuronNeuroglia
Neuron
Neuron
Perikaryon
Perikaryion
Trigger Zone: Cell Integration and Initiation of AP
Trigger Zone: Cell Integration and Initiation of AP
Figure 8-8b: Subthreshold and suprathreshold graded potentials in a neuron
Dendritic spine
Axonal transport
Axonal transport
Antrograde Slow stream ( a few mm per day)
transport protein and microfilament Intermediate
transport mitochondria Fast stream (400mm per day)
transport substance that contained in vesicle Retrograde
Mechanism of the axonal transport
Dynein and kinesin
Axonal transport
Types of Neurons
Diverse Neuron Forms and Functions
Figure 8-3: Anatomic and functional categories of neurons
Types of neurons
MotorSensoryInterneuron
Wave of depolarization
Synapes
Electrical
Chemical
Synapse
Synapse
Metabolism and Synthesis in a Neuron
Figure 8-4: Axonal transport of membranous organelles
Membrane & Channel Changes during an Action Potential
Type of synapses
AxosomaticAxodendriticAxoaxoticDendrosomaticDendrodendroticdendroaxotic
Synapses transmit information
Neurotransmiter
Open or close ion channel or initiate second message
Neuromodulator
do not act directly on synapse but modify neuron sensitivity
Neuroglia
Astrocyte Protoplasmic Fibrous Oligodendrocyte Microglia Ependymal Schwann Satellite cell
Glial Cell Functions
Figure 8-5: Glial cells and their functions
Function of the astrocytes Regulating vasodilation within the CNS moving nutrients, wastes, and other metabolites between neurons and capillaries. Repair Guiding and physically supporting movements and locations of
differentiating neurons in the developing CNS Respond to several stimuli Influence on neuronal survival and activity by regulating constitutes of
ECM, absorb local access of neurotransmitter, release metabolites and neuroactive molecules
Extending processes that associate with or cover synapses in the CNS, affecting the formation, function, and plasticity of these structures.
Forming a barrier layer of expanded processes, called the glial limiting membrane
Astrocytes connect via gap junction very large cellular network for the coordinated
regulation of their various activities in different brain regions
Blood brain barrier
Neuroglia
Oligodendrovyte
Neuroglia
Nerve Fiber
Myelinization
Myelination
Myelination
M.MONSEFI
Myelinization
Nerve Fiber
Myelinated & Un
myelinated
Oligodendrovyte
Schmit-lanterman
Node of Ranvier
Nerve
Nerve
Nerve
Nerve
Repair Of
Injurednerve
Ganglions
Sensory
1:Cranial
2:spinal(dorsal root)
Autonomic
1:Sympathic
2:parasympathic
Ganglia
Ganglia
Sensory Ganglion
Sensory Ganglion
Autonomic Gangilion
Atonomic ganglia
Sensory ganglia Autonomic ganglia Pseudounipolar Larger Associated with
craniospinal nerves No synapses Nerve that enter or exit
belongs to one kind of neurons
Multipolar Smaller Associated with
autonomic nerves Has synapses Nerve that enter or exit
belongs to different nerves
C.N.S. (Brain & Spinal cord)
gray mater : perikarions + dendrites + axons (first portion)
protoplasmic astrocytes + oligodenrocytes + microglia
White mater : axons fibrous astrocytes + oligodendrocytes +
microglia
Braincerebellum
spinal cordspinal nerve
Spinal cordGray mater
Dorsal horn
(sensory neurons)
Ventral horn
(motor neurons)
Epandymal canal
White mater
Myelinated &
Unmyelinated axon
Summary Slide
Spinal cord
Anterior horn cell
Meninges
Dura matterArachnoid Pia matter
Meninges
Choroid plexus
Choroid Plexus
Brain
Cerebellum Gray mater
Molecular layer
Purkinje cell layer
Granular layer
White mater
Myelinated &
unmyelinated axons
Cerebellum
w.m.
White mater granular layer molecular layer
M.MONSEFI
White mater granular layer purkinje cell layer molecular layer
M.MONSEFIM.MONSEFI
Cerebellar cortex
Cerebellum
Cerebrum
Types of the cells in cerebrum
Autonomic system
FunctionTwo neuron networkPreganglionic fiberPostganglionic fiber
Type of Autonomic Fibers
Sympathetic systemParasympathetic system