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 Cranial and spinal nerves outside the central nervous system
 Consists of the brain and spinal cord
 A nerve cell
 Electrochemical process that communicates within the nervous system
 Part of the neuron that receives input from other neurons
 Carries nerve impulses away from the cell body of a neuron

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Nerve
 Bundle of axons or nerve cell fibers
Sensory receptor
 Specialized structure associated with the peripheral end of a sensory neuron specific to detecting a particular sensation and triggering a nerve impulse in response
Somatic nervous system
 Motor pathways of the PNS that lead to skin and skeletal muscle
Autonomic nervous system
 Portion of the PNS that controls organs (viscera), smooth, and cardiac muscle
Myelin
 Fatty covering that protects and insulates an axon
Sensory neurons
 Nerve composed of sensory nerve fibers
Interneurons
 Link motor and sensory neurons in the CNS
Motor neurons
 Transmits impulses from the CNS to effector muscles or glands

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Nerve pathway
 Route a nerve impulse travels
Synapse
 Functional connection between an axon and a dendrite; wireless connection between neurons
Neurotransmitter
 Chemical secreted at the end of an axon on to another neuron or effector muscle or gland
Reflex arc
 Nerve pathway that forms the structural and functional basis for a reflex
Reflex
 An automatic response to a stimulus
Meninges
 3 membranes that cover the brain and spinal cord
Spinal nerves
 Nerves that branch from the spinal cord; part of the PNS

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Cerebrum
 Larger portion of the brain that provides higher level mental functions
Diencephalon
 Region of the brain containing the thalamus and hypothalamus; acts as a relay station for sensory input, as well as to maintain homeostasis
Brain stem
 Includes the medulla oblongata, the pons, and the midbrain; connects brain to spinal cord
Cerebellum
 Coordinates skeletal muscle movements