Chapter 12 Classification of Neurons
Efferent fiber
Axons traveling away from the CNS are called
Unipolar neuron
Fused dendrites and axon
Multipolar neuron
Have two or more dendrited and a single axon
Axon
In a unipolar neuron, the rest process which carries action potentials is usually considered an
Unipolar neuron
In such a neuron, the initial segment lies where the dendtires converge
Visceral motor neuron
Innervate all peripheral effectors other than skeletal muscles that is smooth muscle, cardiac muscle, glands and adipose tissue throughout the body
Ependymal cells, Astrocytes, Oligodendrocytes, Microglia
The central nervous sytem has four types of neuroglia
Sensory receptor
The processes of specialized sensory neurons or cells monitored by sensory neurons
Satellite, Schwann cells
The two types of neuroglia in the PNS
Unipolar neuron
Their axons may extend a meter or more, ending at synapses in the central nervous system.
Motor neuron
These neurons carry instructions from the CNS to peripheral effectors in a peripheral tissue, organ, or organ system
Bipolar Neuron
They are rare neuron
Bipolar Neuron
They are small neurons
Sensory neuron
They are unipolar
Bipolar Neuron
They occur in special sense organs, where they relay information about sight, smell or hearing from receptors cells to other neurons
Interoceptors, Exteroceptors, Propioceptors
Three types of sensory receptors
Pseudounipolar neuron
Unipolar Neurons also called
Motor neuron
efferent division of the PNS
Interneuron
on or more ___ are located between sensory neurons and motor neurons and tthe more complex the response to a given stimulus, the more interneurons are involved
Bipolar Neuron
one axon with the cell body between the two
Bipolar Neuron
one dendrite that branches extensively into dendritic branches at its distal tip
Somatic motor neuron
the cell body of a ____ lies in the CNs, and its axon extends in to the periphery within a peripheral nerve to innervate skeletal muscle fibers at neuromuscular junction
Unipolar neuron
the dendrites and axon are continuous basically, fused and the cell body lies off the one side
Somatic motor neuron
the somatic nervous system infludes all the ____ that innervate skeletal muscles
Sensory neuron
Afferent division of the PNS
Anaxonic Neuron
All cell process look alike
Multipolar neuron
All the motor that control skeletal muscles for example are
Unipolar neuron
Cell body to one side
Sensory neuron
Deliver information from sensory information to the CNS
Interneuron
Distribute sensory information and coordinate motor activity
Visceral motor neuron
It axons in the CNS innervate a second set of visceral motors neurons in peripheral autonomic ganglia
Ependymal cell
Line ventricles (brain) and central canal (spinal cord); assist in producing, circulating and monitoring cerebrospinal fluid
Anaxonic Neuron
Located in the brain and in social organ. And function poorly understood
Multipolar neurons
Longest neuron carry motor commands from the spinal cord to small muscle that move the toes
Astrocyte
Maitain blood-brain barrier; provide structural support; regulate ion, nutrient and dissolved-gas concentrations; absorb and recycle neurotransmitters; form scar tissue after injury
Interoceptor
Monitor the digestive, respiratory, cardiovascular, urinary and reproductive system
Proprioceptor
Monitor the position and movement of skeletal muscle and joints
Interneuron
Most located within the brain and spinal cord, but some are in autonomic ganglia
Unipolar
Most sensory neurons of the peripheral nervous system are
Oligodendrocyte
Myelinate CNS axon; provide structural framework
anaxonic, bipolar, unipolar, mutipolar
Neurons are classified as_____ on the basis of the relationship of the dendrites to the cell body and the axon
Sensory, motor, interneuron
Neurons function can be categorize as
Bipolar Neuron
One dendrite, one axon
Interneuron
Play a part in all higher functions, such as memory, planning and learning
Sensory neuron
Process (afferent fibers) extend between sensory receptor and the central nervous system
Exteroceptor
Provide information avout the external environment in the form of touch, temperatures, or pressure sensation and the more complex senses of taste, smell, sight, equilibrium and hearing
Interoceptor
Provide sensations of distension, deep pressure and pain
Microglia
Remove cell debris, wastes, and pathogens by phagocytosis
Anaxonic Neuron
Small and have no anatomical features that distinguish dendrites from axons
Schwann cell
Surround all axons in PNS; responsible for myelination of peripheral axons; participate in repair process after injury
Satellite cell
Surround neuron cell bodies in ganglia; regulate O2, CO2, nutrient and neurotransmitter levels around neurons in ganglia
Multipolar neuron
THe most common neurons in the CNS
Multipolar neurons
The axons can be as long as those of unipolar neurons
Sensory ganglia
The cell bodies of the sensory neurons are located in
Visceral sensory neuron
monitor internal conditions and the status of other organ systems
Somatic sensory neuron
monitor the outside world and our position within it
Interneuron
outnumber all other types of neurons combined