BIO 201 - Chapter 11 Complete Guide

BIO 201 - Chapter 11 Complete Guide Absolute refractory period ️Period following stimulation during which no additional action potential can be evoked. Acetylcholine ️Chemical transmitter substance released by some nerve endings. Action potential ️A large transient depolarization event, including polarity reversal that is conducted along the membrane of a muscle cell or a nerve fiber. Astrocyte ️A type of CNS supporting cell; assists in exchanges between blood capillaries and neurons. Axoaxonic synapse ️Axon connects to another axon. Axodendritic synapse ️Synapses between the axon endings of one neuron and the dendrites of other neurons. Axon ️Neuron process that carries impulses away from the nerve cell body; efferent process; the conducting portion of a nerve cell. Axon hillock ️Cone shaped area of the cell body. Conveys signals that are coming from dendrites away from cell body, etc. Axosomatic synapse ️Synapses between axon endings of one neuron and cell bodies (soma) of other neurons. Catecholamines Central nervous system ️Epinephrine, norepinephrine, and dopamine; a class of amines that act as chemical transmitters. Dendrite ️Branching neuron process that serves as a receptive, or input, region; transmits an electrical signal toward the cell body. Depolarization ️Loss of a state of polarity; loss or reduction of negative membrane potential. Ependymal cell ️A type of CNS supporting cell; line the central cavities of the brain and spinal cord. Excitatory postsynaptic potential ️Depolarizing graded potential in a postsynaptic neuron. Ganglion ️Collection of nerve cell bodies outside the CNS. Graded potential ️A local change in membrane potential that varies directly with the strength of the stimulus, declines with distance. Gray matter ️Gray area of the central nervous system; contains neuronal cell bodies and their dendrites. Hyperpolarization ️An increase in membrane potential in which the membrane becomes more negative than resting membrane potential. Inhibitory postsynaptic potential ️A graded potential in a postsynaptic neuron that inhibits action potential generation; usually hyperpolarizing. Interneuron/Association neuron ️Nerve cell located between motor and sensory neurons that shuttles signals through CNS pathways where integration occurs. Motor neuron ️Nerves that carry impulses leaving the brain and spinal cord, and destined for effectors. Multipolar neuron ️Neurons with three or more processes; most common neuron type in the CNS. Myelin ️Fatty insulating sheath that surrounds all but the smallest nerve fibers. Neuroglia ️Nonexcitable cells of neural tissue that support, protect, and insulate the neurons; glial cells. Neuron ️Cell of the nervous system specialized to generate and transmit electrical signals (action potential and graded potentials.) Neuronal pool ️Functional groups of neurons that process and integrate information. Node of Ranvier ️Gaps in the sheath where adjacent Schwann cells along on an axon fo not touch one another. Oligodendrocyte ️A type of CNS supporting cell that composes myelin sheaths. Parallel processing ️The processing of many aspects of a problem simultaneously; the brain's natural mode of information processing for many functions, including vision. Contrasts with the step-by-step (serial) processing of most computers and of conscious problem solving. Peripheral nervous system ️Portion of the nervous system consisting of nerves and ganglia that lie outside of the brain and spinal cord. Postsynaptic neuron ️Ion channels open in postsynaptic membrane. Presynaptic neuron ️Ca++ channels open in presynaptic axonal terminal. Reflex Arc - Step 1 ️Receptor - site of stimulus Reflex Arc - Step 2 ️Sensory - Action Potential sent along afferent pathway to CNS. Reflex Arc - Step 3 ️Integration - interneuron processes incoming sensory information a