5/24/25, 5:37 PM Complete Nervous System Notes
Complete Nervous System No
tes
Chapter 13:
Functions of the Nervous System:
Sensation - receiving information
Integration - combining sensory info with higher cognitive function
Association areas accomplish this function
Response - motor functions carried out by effectors
Both conscious and unconscious pathways exist
Central and Peripheral Nervous System:
CNS
Brain and spinal cord
Housed within cranial and vertebral cavities
PNS
Nerves OUTSIDE of brain and spinal cord
Outside of bony protection
CNS and PNS
Neurons = cells capable of communication
Glial cells = cells that provide structure and support to neurons
Functional Divisions of the Nervous System:
Sensory - sends info TOWARDS CNS
AFFERENT (Sensory) neurons
Integration - occurs in brain and spinal cord
INTERNEURONS
Response - communicate with effectors
Effectors = muscle or organ that responds
EFFERENT (motor) neurons
Classification Based on Innervation:
Named based on location nerve innervates
SNS (somatic) = conscious perception and voluntary motor respons
es; skeletal muscle
ANS (Autonomic) = Involuntary, maintains homeostasis; smooth mu
scle, cardiac muscle, and glands
Anatomy of Neurons:
Responsible for communication within NS
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, 5/24/25, 5:37 PM Complete Nervous System Notes
Cell body (soma) - houses organelles like nucleus, nucleolus, riboso
mes, and endoplasmic reticulum
Dendrites - receive signals from other neurons
Axon - begins at axon hillock
Sends signals to OUT to other neurons
Each neuron has 1 axon
Synapses - junctions where neurons communicate with other cells
Axons may be wrapped in myelin
Gaps in myelin create neurofibril nodes
Muscle axonal branches (axon terminals) allow a neuron to commu
nicate with multiple other cells
Anatomical Classication of Neurons:
Unipolar neurons - only one process from cell body that splits into a
n axon and dendrites
MOST SENSORY NEURONS ARE UNIPOLAR
Bipolar neurons - two processes, one dendrite and one axon, extend
from cell body
Sensory for smell and vision
Multipolar neuron - many dendrites and one axon
MOST NEURONS IN THE BODY ARE MULTIPOLAR
Functional Classification of Neurons:
Sensory neurons - collect and send info to CNS
Interneurons - integrate and process info from sensory neurons
Motor neurons - communicate with effectors to do an action
Glial Cells:
Supportive cells found throughout NS
Can multiply and divide
Glial cells of CNS
Astrocytes - regulate extracellular environment (make up blood br
ain barrier [BBB])
Oligodendrocytes - myelination
Microglia - immune defense and waste removal
Ependymal cells - produce cerebrospinal fluid (CSF)
Glial Cells of PNS
Satellite cells - regulate extracellular environment
Cluster around cell bodies
Similar to astrocytes in CNS
Schwann (neurilemma) cells - myelination
Similar to oligodendrocytes of CNS
Myelin:
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Complete Nervous System No
tes
Chapter 13:
Functions of the Nervous System:
Sensation - receiving information
Integration - combining sensory info with higher cognitive function
Association areas accomplish this function
Response - motor functions carried out by effectors
Both conscious and unconscious pathways exist
Central and Peripheral Nervous System:
CNS
Brain and spinal cord
Housed within cranial and vertebral cavities
PNS
Nerves OUTSIDE of brain and spinal cord
Outside of bony protection
CNS and PNS
Neurons = cells capable of communication
Glial cells = cells that provide structure and support to neurons
Functional Divisions of the Nervous System:
Sensory - sends info TOWARDS CNS
AFFERENT (Sensory) neurons
Integration - occurs in brain and spinal cord
INTERNEURONS
Response - communicate with effectors
Effectors = muscle or organ that responds
EFFERENT (motor) neurons
Classification Based on Innervation:
Named based on location nerve innervates
SNS (somatic) = conscious perception and voluntary motor respons
es; skeletal muscle
ANS (Autonomic) = Involuntary, maintains homeostasis; smooth mu
scle, cardiac muscle, and glands
Anatomy of Neurons:
Responsible for communication within NS
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, 5/24/25, 5:37 PM Complete Nervous System Notes
Cell body (soma) - houses organelles like nucleus, nucleolus, riboso
mes, and endoplasmic reticulum
Dendrites - receive signals from other neurons
Axon - begins at axon hillock
Sends signals to OUT to other neurons
Each neuron has 1 axon
Synapses - junctions where neurons communicate with other cells
Axons may be wrapped in myelin
Gaps in myelin create neurofibril nodes
Muscle axonal branches (axon terminals) allow a neuron to commu
nicate with multiple other cells
Anatomical Classication of Neurons:
Unipolar neurons - only one process from cell body that splits into a
n axon and dendrites
MOST SENSORY NEURONS ARE UNIPOLAR
Bipolar neurons - two processes, one dendrite and one axon, extend
from cell body
Sensory for smell and vision
Multipolar neuron - many dendrites and one axon
MOST NEURONS IN THE BODY ARE MULTIPOLAR
Functional Classification of Neurons:
Sensory neurons - collect and send info to CNS
Interneurons - integrate and process info from sensory neurons
Motor neurons - communicate with effectors to do an action
Glial Cells:
Supportive cells found throughout NS
Can multiply and divide
Glial cells of CNS
Astrocytes - regulate extracellular environment (make up blood br
ain barrier [BBB])
Oligodendrocytes - myelination
Microglia - immune defense and waste removal
Ependymal cells - produce cerebrospinal fluid (CSF)
Glial Cells of PNS
Satellite cells - regulate extracellular environment
Cluster around cell bodies
Similar to astrocytes in CNS
Schwann (neurilemma) cells - myelination
Similar to oligodendrocytes of CNS
Myelin:
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