CHAP 5 Flashcards
contains 2 major components: nucleus & cytoplasm; both maintain the viability of entire organ
Cell Body
consists of protein molecules & watery substance enclosed within the cell membrane; contains organelles
Cytoplasm
Efferent structures that transmit info away from the cell body to other neurons or target organs
Axon
Afferent, transmitting info to the cell body from other cells via synaptic sites; short with many branches
Dendrite
Endoplasmic structures in neuronal cell bodies that participate in protein synthesis
Nissl bodies
Point of contact between two neurons where the neurotransmitter is released
Synapse
Small scavenger glia cells that digest and remove cellular debris from the CNS
Microglia Cells
Neuroglial cells that support nerve cells and contribute to blood-brain barrier
Astrocyte Cells
Glia cells that produce the myelin sheath around the axons in the CNS
Oligondendroglia Cells
glia cells that form myelin around the axons in the PNS
Schwann Cells
layer of connective tissue that wraps around axons in the PNS
Endoneurium
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Perineurium
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Epineurium
Electrical impulse representing a transient fluctuation in membrane potentials, which are propagated along axonal process to activate postsynaptic terminals
Action potentials
changes in membrane potentials in which the cellular interior changes from negative (resting potential) to positive
Depolarization
Electrical resting state of a cell characterized by the polarity of ions inside and outside the cell
Polarization
increased internal negativity across a cell membrane causing changes in voltage
Hyperpolarization
how nerve cells communicate; represent all neuronal activity; activate the release of a neurotransmitter in a presynaptic neuron
Nerve Impulse
impulses that activate the postsynaptic cell to generate an action potential
Excitatory Postsynaptic Potentials
impulses that inhibit the capacity of a postsynaptic cell to generate an action potential
Inhibitory Postsynaptic Potentials (IPSP)
cellular changes marked by swelling, dissolution of cellular organelles (specifically Nissl bodies) and shifting of the nucleus from its central position to the periphery in response to unjury
Chromatolysis
have 2 processes (dendrite & axon) one extending from each pole of the body; found in retina & inner ear
Bipolar Cell
T-shape with one process extending from the body & dividing into an axon & dendrite away from the cell body; in spinal dorsal roots
Unipolar Cell
neurons containing many dendrites and one axon; most cells in the CNS
Multipolar Cell
subdivisons of the embryonic neural tube, each with a wall neuroectoderm and a cavity
Vesicles
cellular state immediately following the action potential in which no other action potential can be initiated by the cell
Absolute refractive period
constantly adjusts the distribution of sodium and potassium ions across the cellular membrane; transports sodium out of the cell & potassium into the cell
Sodium-potassium pump
retrograde chromatolytic changes in the soma marked by disintegration of the granules of the Nissl bodies after damage to an axon
Axonal Reaction
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Axonal Sprouting
have a long axon, ranging from inches to feet; many form sensory or motor tracts connecting cells across long distances
Golgi Type I Cells
have short axonal process; such as interneurons that connect with other adjacent cells
Golgi Type II Cells
the segment of myelin between 2 nodes
Internode
path finders; contain sensory or motor inclination; navigate the directional axonal path by finding ways through the biological environment of enormous cellar density to connect with target neurons
Growth Cones
The nerve cell is not generating action potential
Resting Potential
organelle of the cellular cytoplasm enzymes providing the principle energy source for the cell
Mitochondria
neurons that are not connected, weakly connected, or have redundant connections die for cortical maturation to occur
Neural Pruning
Structural changes in a distal portion of an axon after it is sectioned and disconnected from the cell body as a result of an injury
Wallerian Degeneration
Neurotransmitter released by cholinergic neurons and widely disturbed in body tissues; primarily regulates some brain activity and most of the muscular activity of the PNS
Acetylcholine
Enzyme that breaks the neurotransmitter acetylcholine into choline and acetate, contributing to the termination of the postsynaptic current and signal; much of the choline released is recaptured by the presynaptic terminal
Acetylcholinesterase
one of the inhibitory nerotransmitters secreted by neurons in the brainstem; increased & decreased secretion is associated with schizophrenia & Parkinsonism
Dopamine
major inhibitory neurotransmitter for the CNS; small molecule neurotransmitter; a monoamine that derives from amino acids
Y-aminobutyric acid (GABA)
one of primary neurotransmitters in the PNS; released by the postganglionic sympathetic neurons; responsible for flight or flight reaction
norepinephrine
important neurotransmitter of CNS; most of it found in blood platelets & gastrointestinal tract
Serotonin
