Chapter 2 Flashcards
a neuron’s often bushy, branching extensions that receive messages and conduct impulses toward the cell body
Dendrites
the neuron extension that passes messages through its branches to other neurons or to muscles or glands
axon
the cell’s life-support center (of a neuron)
Cell Body
a neural impulse; a brief electrical charge that travels down an axon.
Action Potential
a fatty tissue layer segmentally encasing the axons of some neurons; enables vastly greater transmission speed as neural impulses hop from one node to the next
Myelin Sheath
a part of the neuron that forms junctions with other cells
Terminal branches of axon
the scientific study of the links between biological (genetic, neural, hormonal) and psychological processes.
Biological Psychology
a nerve cell; the basic building block of the nervous system
neuron
cells in the nervous system that support, nourish, and protect neurons; they may also play a role in learning, thinking, and memory
glial cells(glia)
the level of stimulation required to trigger a neural impulse
threshold
a brief resting pause that occurs after a neuron has fired; subsequent action potentials cannot occur until the axon returns to its resting state.
refractory period
a neuron’s reaction of either firing (with a full-strength response) or not firing
all-or-none response
the junction 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 or synaptic cleft.
synapse
a neurotransmitter’s reabsorption by the sending neuron
reuptake
“morphine within” – natural, opiate-like neurotransmitters linked to pain control and to pleasure
endorphins
chemical messengers that cross the synaptic gaps between neurons.
neurotransmitters
a molecule that increases a neurotransmitter’s action
agonist
a molecule that inhibits or blocks a neurotransmitter’s action
antagonist
the body’s speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous system
nervous system
the brain and spinal cord
central nervous system (CNS)
bundled axons that form neural cables connecting the central nervous system with muscles, glands, and sense organs.
nerves
neurons that carry incoming information from the sensory receptors to the brain and spinal cord
sensory (afferent) neurons
neurons that carry outgoing information from the brain and spinal cord to the muscles and glands
motor (efferent) neurons
neurons within the brain and spinal cord; communicate internally and process information between the sensory inputs and motor outputs
interneurons
the division of the peripheral nervous system that controls the body’s skeletal muscles. Also called the skeletal nervous system
somatic nervous system