Nervous System
Monitors environments, integrates sensory information, and coordinates voluntary and involuntary responses
Central Nervous System
Consists of brain and spinal cord. Integrates and coordinates the processing of sensory data and the transmission of motor commands.
Peripheral Nervous System
System of which all communication between the CNS and the rest of the body occurs through.
Afferent Division
division of nervous system which transmits sensory information from somatic and visceral receptors and special sense organs to the CNS
Efferent Division
division of nervous system which carries motor commands to muscles and glands
Somatic Nervous System
the division of the peripheral nervous system that controls the body's skeletal muscles. Also called the skeletal nervous system
Autonomic Nervous System
the part of the nervous system of vertebrates that controls involuntary actions of the smooth muscles and heart and glands
Neurons
Basic units of the nervous system
Neuroglia
Regulate the environment around neurons, provide a supporting framework for neural tissue, and act as phagocytes.
Dendrites
Receive incoming signals
Axon
Carries ongoing signals toward one or more synaptic terminals
Synaptic Terminals
relay signals to other cells by releasing chemical messengers called neurotransmitters.
Nissl Bodies
Clusters of rough ER and free ribosomes.
Multipolar Neuron
Two or more dendrites and a single axon. The most common of all neurons in the CNS.
Unipolar Neurons
Dendrites and axon are continuous and the cell body lies off to one side.
Bipolar Neurons
have two processes -- one dendrite and one axon -- with the cell body between them
Sensory Neurons
neurons that carry incoming information from the sense receptors to the central nervous system.
Somatic Sensory Receptors
Detect information about the outside world or our physical position within it.
Visceral sensory receptors
monitor other internal tissues such as smooth muscle, cardiac muscle and glands
Interneurons
central nervous system neurons that internally communicate and intervene between the sensory inputs and motor outputs.
Astrocytes
largest, most numerous glial cells; maintain blood-brain barrier to isolate CNS from general circulation; provide structural support for CNS; regulate ion and nutrient concentrations; perform repairs to stabilize tissue and prevent further injury
Oligodendrocytes
wrap CNS axons in a myelin sheath
Myelin
a white fatty substance that forms a medullary sheath around the axis cylinder of some nerve fibers
White Matter
composed of myelinated axons.
Grey Matter
is composed primarily of cell bodies, inerneurons, and unmylinated fibers
Microglia
smallest neuroglial cells; phagocytic cells that engulf cellular debris, waste products and pathogens. increase in number as a result of infection or injury
Ependymal Cells
in cns only, epithellal cells in a single layer, that line the spaces in the brain and spinal cord, and proudce cerebrospinal fliud (csf)
Ependyma
thin epithelial membrane lining the ventricles of the brain and the spinal cord canal
Satellite Cells
support ganglia in the PNS
Schwann Cells
Supporting cells of the peripheral nervous system responsible for the formation of myelin.
Ganglia
clusters of neuron cell bodies in the PNS
Nerves
The white matter of the PNS
Center
A collection of neuron cell bodies with a common function
Nucleus
A center with a discrete boundary
Neural Cortex
thick layer of grey matter
Columns
Larger groups of tracts in the spinal cord
Tracts
The white matter of the CNS contains bundles of axons that share common origins, destinations, and functions.
Pathways
Link the center of the brain with the rest of the body
Sensory pathways
distribute sensory information from sensory receptors to processing centers in the brain
Motor Pathways
Begin at CNS centers concerned with motor activity and end at the skeletal muscles they control.