Nervous System Flashcards
Central Nervous System (CNS)
The Brain and the Spinal Cord
Peripheral Nervous System (PNS)
A system of nerves that connects the outlying parts of the body with the central Nervous System
Afferent Neurons/Sensory Division
Nerve cells that carry impulses toward the CNS
Efferent Neurons/Motor Division
Neurons that conduct impulses away from the CNS
Somatic Nervous System/Voluntary Nervous System
Allows us to voluntarily control our skeletal muscles
Autonomic Nervous System/Involuntary Nervous System
Regulates involuntary actions in the human body
Neuroglia
The nonneuronal tissue of the CNS that performs supportive and other functions A.K.A. glia
Asrocytes
Abundant Star-Shaped cells that anchor neurons to nearby blood capillaries
Microglia
Dispose of debris, including dead brain cells and bacteria
Ependymal Cells
Circulate the cerebrospinal fluid that fills the cavities in which they lie
Oligodendrocytes
Wrap themselves around nerve fibers creating myelin sheaths in the CNS
Schwann cells
Form myelin sheaths around nerve fibers in the PNS
Neuron
Highly specialized cells that transmit and receive electrical impulses
Dendrites
Branching extensions of neurons that carry the electrical impulses to the cell body
Axon
Neuron process that carries the electrical impulses away from the cell body
Neurotransmitters
Chemical released by the neurons that may stimulate the nerve cells
Nodes of Ranvier
Gaps between the myelin sheaths created by the schwann cells
Ganglia
Small collections of cell bodies in the PNS & CNS
Tracts
Small collections of cell bodies in the CNS
Nerves
Small collections of cell bodies in the PNS
Association Neurons/Interneurons
Connect the motor and sensory neurons located in the CNS
Multipolar Neurons
Neurons that have several different processes
Bipolar Neurons
Neurons that have two processes the axon and the dendrite
Unipolar Neurons
Neurons that only have one process
Polarized
Resting stage of the nerve impulse
Depolarization
Inward rush of Sodium ions changes the polarity of the cell to be positive
Repolarization
Inward rush of Potassium ions changes the polarity of the cell to be neutral
Reflexes
Rapid, predictable, automatic responses to a stimuli
Somatic reflexes
Reflexes that stimulate the skeletal muscles
Autonomic reflexes
Reflexes that regulate smooth muscles
