the bushy, branching extensions of a neuron that recieve messages and conduct impulses toward the cell body
the extension of a neuron, ending in branching terminal fibers, through which mesages pass to other neurons or to muscles or glands
the juntion between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron. The tiny gap at this junction is called the synaptic gap of cleft.
chemical messengers that traverse the synaptic gaps between neurons. They bind to receptor sites on the receiving neuron, thereby influencing whether that neuron will generate a neural impulse.
"morphine within"; natural, opiatelike neurotransmitters linked to pain control and to pleasure
peripheral nervous system
the sensory and motor neurons that connect the central nervous system to the rest of the body
neurons that carry incoming information from the sense receptors to the central nervous system.
neurons that carry outgoing information from the sense receptors to the central nervous system to the mucles and glands
central nervous system neurons that internally communicate and intervene between the sensory inputs and motor outputs
sympathetic nervous system
part of the nervous system that arouses the body, mobilizing its energy in stressful situations.
parasympathetic nervous system
division of the automatic nervous system that calms the body, conserving its energy
the body's slow chemical communication system; a set of glands that secrete hormones into the blood stream
chemical messangers, mostly those manufactured by the endocrine glands, that are produced in one tissue and affect another