Quiz: Nervous System, Ch 9 Flashcards
Central nervous system is comprised of…
Brain and spinal cord
Functions of the autonomic nervous system…
Innervation of glands, smooth / cardiac muscles
Describe the nervous system integrative function…
Analyzes sensory information, stores information, makes decisions
Functions of astrocytes…
Support and brace neurons; anchor neurons to blood vessels; control chemical environment around neurons; guide migration of young neurons
The ciliated CNS neuroglia that play an active role in moving the cerebrospinal fluid…
Ependymal cells
Bipolar neurons are commonly found…
In the retina of the eye
Characteristics of neurons…
High metabolic rate; extreme longevity; conduct impulses; amitotic
Part of a neuron that conducts impulses away from its cell body
Axon
Collections of nerve cell bodies in the PNS…
Ganglia
Neuron whose primary function is to connect other neurons…
Interneuron (aka. association or relay neuron)
Neuroglia that control the chemical environment around neurons by buffering ions such as potassium and recapturing and recycling neurotransmitters…
Astrocytes
Schwann cells are functionally similar to…
Oligodendrocytes (found in CNS, whereas Schwann cells are found in PNS)
The interior of the cell becomes less negative due to an influx of sodium ions…
Depolarization
The specific period during which potassium ions diffuse out of the neuron due to a change in membrane permeability…
Repolarization
Also called a nerve impulse transmitted by axons…
Action potential
Phase where the neuron cannot respond to a second stimulus, no matter how strong…
Absolute refractory period
Ion channel that opens in response to a change in membrane potential and participates in the generation and conduction of action potentials….
Voltage-gated channel
Saltatory conduction is made possible by…
Myelin sheath
First cellular gate to open immediately after an action potential has peaked…
Potassium (K+)
The interior surface of a cell membrane of a resting (nonconducting) neuron differs from the external environment in that the interior is…
Negatively charged and contains less sodium
Numerous nerve impulses arriving at a synapse at closely timed intervals exert a cumulative effect (called)…
Temporal summation
Stimulation of a postsynaptic neuron by many terminals at the same time (called)…
Spatial summation
An insufficient stimulus to cause neural response…
Subthreshold stimulus
Any stimulus below this intensity will result in no response in a neuron…
Threshold stimulus
An impulse from one nerve cell is communicated to another nerve cell via…
Synapse
Prevents an impulse from being transmitted directly from one neuron to another…
Synaptic cleft
Short-lived, local changes in membrane potential of varying amplitudes…
Graded potentials
An inhibitory postsynaptic potential (IPSP) is associated with…
Hyperpolarization
Role of acetylcholinesterase…
Destroys ACh a brief period after its release by the axon endings
An excitatory neurotransmitter secreted by motor neurons innervating skeletal muscle…
Acetylcholine
Substance released at axon terminals to propagate a nervous impulse…
Neurotransmitter
Chemical classes of neurotransmitters…
Amino acids, gasotransmitters, monoamines, trace amines, peptides and purines
The movement of ions across excitable membranes is affected by…
Sodium gates in the membrane, which can open in response to electrical potential changes
Neuroglia that function as phagocytes…
Microglia
Number of cranial nerves and spinal nerves…
Cranial 12 pairs (24)
Spinal 31 pairs (62)
Organization of nervous system…
Central Nervous (CNS) -> Peripheral (PNS)
PNS -> Sensory (afferent) and Motor (efferent) divisions
Motor -> Somatic Nervous and Autonomic (ANS)
ANS -> Sympathetic and Parasympathetic divisions
Functional classifications of neurons…
Sensory (afferent), Motor (efferent), Interneurons (integrative)
Structural classifications of neurons…
Multipolar (CNS, inter and motor), Bipolar (special sensory), Unipolar (PNS, sensory)
White matter vs Gray matter…
White (dense collection of myelinated fibers)
Gray (mostly soma and unmyelinated fibers)
Gaps in the myelin sheath between adjacent schwann cells…
Nodes of Ranvier
Ion channels that open with the binding of a specific neurotransmitter…
Chemically/Ligand-gated channels
Ion channels that open and close in response to physical deformation of receptors…
Mechanically gated channels
An autoimmune disease characterized by visual disturbances, weakness, loss of muscular control and urinary incontinence, on account of…
Severed nerve fibers and myelin sheaths becoming nonfunctional scleroses; shunting and short-circuiting of nerve impulses occur; called Multiple Sclerosis
