Nervous
System
Delanie Cyr
Jacob Butcher
Jacklyn Jaronik
Claudia Bishop
Nervous system: Central and
Peripheral

The Nervous system is stream lined to send rapid signals
from cell to cell to maintain homeostasis and
coordinate body organs and functions.
Central and Peripheral
Systems
 There
are two basic types of nervous
systems:
 CNS
(Central Nervous System)
 PNS
(Peripheral Nervous System)
Central Nervous System
 Consists
 It
of the brain and spinal cord
coordinates information received from
sensory receptors and initiates responses
Peripheral Nervous System
 Contains
a afferent division composed of
sensory receptors and sensory neurons,
and an efferent division composed of
motor neurons.
Sensory Receptors and Motor
Nerves
 Sensory
receptors detect changes in the
environment and transmits this information
along sensory or afferent nerves to the
CNS
 Motor
nerves transmits impulses from the
CNS to the PNS
Structure of Nervous Tissue

Located in the brain, spinal cord, ganglia, and nerves.

It is composed of two types of cells, Neurons and
Neuroglia

Neurons conduct action potentials and are the
structural and functional units of nervous tissue

Neuroglia are cells that support, protect, and furnish
nutrients to neurons, and augment the speed of neuron
transmission
Structure of a Neuron

Can be over 3 feet long (longest nerve in your body)

Three basic parts to a neuron:

Dendrites- receive information from receptors or other
neurons and send it back out to the cell body

Cell Body-usually has a triangular or cone shaped area
called the axon hillock

Axon- extends from the axon hillock, is the elongated
fiber that extends from the cell body to the terminal
endings and transmits the neural signal.
Structure of a Neuroglia Cell

Generally smaller and more abundant the neurons.

Six types of neuroglia cells, four located in the CNS, and
two located in the PNS.

CNS:
Astrocytes
Oligodendrocytes
Microglia
Ependymal Cells







PNS:
Schwann Cells
Satellite Cells
Classification of a Neuron
 Three
classifications of a neuron based on
their function:

Sensory(afferent)- changes the stimulation into an
action potential or nervous impulse that travels along
the axon to a spinal cord.

Interneuron- structurally a multipolar neuron and
comprises about 90% of the neurons in the CNS.

Motor neuron (efferent)- takes the impulse out of the
spinal cord via a spinal nerve to an effector.