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What is the nervous system divided into?
Central Nervous System - brain and spinal cord
Peripheral Nervous System - other nerves
How is the nervous system organized?
Sensory (afferent) Division
Peripheral Nervous System
Motor (efferent) Division
Autonomic and Somatic Nervous System
Sympathetic and Parasympathetic Division
What is the Sensory (afferent) division?
Sends impulses from the senses to the Central Nervous System
What is the Peripheral Nervous System?
Comprised of all nerves not in the brain or spinal cord
What is the Motor (efferent) system?
Sends impulses from the Central Nervous System to muscles and glands
What is the Autonomic Nervous System?
Involuntary muscle control
What is the Somatic Nervous System?
Voluntary Nervous System
What is the Sympathetic Division?
Part of the Autonomic Nervous System
Initiated during emergency situations
Fight or Flight
What is the Parasympathetic Division
Reduces sympathetic response
Resting functions like Digestion and Urination
What is the function of the nervous system?
It is the master control center for the body
What are the 3 things that the nervous system uses to do it’s job?
Sensory Input, Integration, and Response
What is Sensory Input?
It detects stimuli inside and outside of the body
What is Integration?
It processes and interprets information
What is Response in the NS?
It is the activation of muscles or glands
What is the function of Neurons?
Conducts impulses around the body
10% of all Nerve Cells
What is the function of Neuroglia
Support Cell, Insulate, and Protects the Neurons
90% of all Nerve Cells
What do all Neuron structures have?
Cell body with processes extending outwards
What does the Cell Body Contain?
Nucleus, cytoplasm, and organelles
How are Processes divided?
Dendrites (impulses toward the body)
Axon (impulses away from the body)
Axon terminals release neurotransmitter
Pass impulses to next neuron
What are the two ways neurons are classified?
Number of processes
Function
Neurons Classification (number of processes)
Unipolar (one processes)
Bipolar (two processes)
Multipolar (many processes)
Neuron Classification (function)
Afferent (carry towards CNS)
Efferent (carry away from the CNS)
Inter (connect the afferent to efferent)
What are axon’s wrapped in?
Myelin, which is a waxy insulation
How is myelin formed?
Schwann cells wrap itself around the axon
Like a scarf
Outer layer is called the neurilemma
Myelin wrappings are called Myelin Sheaths
Made of Schwann Cells
Gaps called node of Ranvier
What is the function of Astrocytes?
Within the CNS
Support and Anchor neurons to nearby capillaries
What is the function of Microglia?
Within the CNS
Provides immune response to the CNS
What is the function of Ependymal Cells?
Within the CNS
Secrete cerebrospinal fluids
What is the function of Oligodendrocytes?
Within the CNS
Myelin insulation for nerves in CNS
What is the function of Satellite Cells?
Within the PNS
Support and anchor neurons to PNS
What is the function of Schwann Cells?
Within the PNS
Myelin insulation for nerves in PNS
What is a nerve impulse?
An electrical signal that travels along the neuron
What is resting potential?
Intracellular Space = negative charge
Extracellular Space = positive charge
How is a nerve impulse passed along a neuron?
Neuron is stimulated by environment or another neuron
Sodium rushes into neuron and reverses the charge (depolarization and action potential)
Potassium diffuse out of the neuron (repolarization)
Sodium-potassium pump restores the ion concentration back to resting potential
What is a synapse?
Where two neurons meet
What is a synaptic cleft?
The space between two neurons
What events occur at a synapse?
Impulse stimulates vesicles to release neurotransmitters across the synaptic cleft
The neurotransmitters cause channels to open in the next neuron
Note 
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