25 terms

psychology chapter 3 - nervous system

individual nerve cells
three parts of a neuron
cell body, dandrites, axons
cell body of a neuron contains:
the cells nucleus
branches that extend out from the cell body and receive messages from other neurons
branches that carry messages away from the cell body
bundle of many long neurons outside the brain and spinal chord
the particles carrying either a positive of a negative electrical charge, most ions inside neurons are negatively charged
neuron membranes
semi permiable, , only certain chemicals can permeate
theprocess by which one neuron membrane touches another, and the semi permiability goes down, allowing positively charged ions to enter
action potential
caused by depolarization, axon becomes more permeable, producing a depolarization
all or none principal
neurons transmitted signals to other neurons only when depolarization was strong enough to trigger an action potential
myelin sheath
white, fatty coating encasing many axons, increases the speed at which the axon conducts neural impulses
victims of multiple schlerosis have problems with their
myelin sheath
synaptic gap
gap between neurons
nuero transmitters
carriers of neutral message across the synaptic gap
glial cells help neurons carry out their goals in three ways
transport nutrients from blood vessels to neurons, some produce the myelin sheath, and change the chances of synaptic transmission
two divisions of the nervous system
central, peripheral
central nervous system
consists of brain and spinal chords
peripheral nervous system
composed of the nerves that branch from the brain and the spinal cord to the body
two parts of the peripheral nervous system
somatic, autonomic
somatic nervous system
carries messages from the central nervous system to the skeletal muscles that control movements of the body
autonomic nervous system
composed of nerves that carry messages to the glands and visceral organs
divisions of the autonomic nervous system
sympathetic nervous system, parasympathetic nervous system
sympathetic nervous system
prepares the body to respond to psychiological or physical stress
parasympathetic nervous system
maintains balanced regulation of internal organs