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39 Cards in this Set
- Front
- Back
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smooth muscle cells have _____ whereas skeletal muscle fibers do not.
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calmodulin
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ACh receptors are found mainly in
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junctional folds
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Single-unit smooth muscle cells can stimulate each other because they have _____.
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gap junctions
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T or F? Slow oxidative fibers have an abundance of myoglobin and glycogen.
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F. just myoglobin.
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difference between afferent and efferent neurons
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afferent = sensory; specialized to detect stimuli like heat, light, pressure, chemicals & transmit information about them TOWARD the CNS
efferent = motor; send signals FROM CNS to muscle and gland cells (the effectors) |
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Universal characteristics of muscle
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responsiveness (excitability)
conductivity contractility extensibility elasticity |
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Universal properties of nerve cells
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excitability (irritability)
conductivity secretion |
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soma
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cell body of a neuron
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Neuron support cells (= neuroglia or glial cells)
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Astrocytes
Oligodendrocytes Ependymal cells Microglial cells |
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saltatory conduction
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process where action potentials appear to jump from node to node; transports information very quickly
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astrocytes
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most abundant glial cells in the CNS
cover the entire brain surface and most nonsynaptic regions of the neurons in the gray matter of the CNS. Functions: form a supportive framework for nervous tissue have extensions called perivascular feet, which contact the blood capillaries and form a tight seal called the blood-brain barrier convert blood glucose to lactate and supply this to the neurons for nourishment secrete nerve growth factors that promote neuron growth and synapse formation regulate IF chemical composition, control movement of molecules and ions from the blood occupy space of dying neurons |
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Oligodendrocyte
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large bulbous body with many arm-like extensions, which each wrap around a different neuron's axon
wrapping called a myelin sheath (IN CNS) |
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microglial cell
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least numerous..phagocytize and destroy microorganisms, wander through CNS and replicate in response to infection
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ependymal cell
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(in CNS)
produce cerebrospinal fluid line the ventricles of the brain and the central canal of the spinal cord ependymal cells + nearby blood capillaries make the choroid plexus cilia of ependymal cells help circulate the CSF |
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Schwann cell
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form neurilemma around all PNS nerve fibers and myelin around most of them; aid in regeneration of damaged nerve fibers
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satellite cells
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surround somas of neurons in the ganglia; provide electrical insulation and regulate chemical environment of neurons (in PNS)
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Why is whole milk recommended for babies?
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myelination!
myelin is 80% lipid & 20% protein. high lipid diet necessary for formation |
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unmyelinated axons in the PNS
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associated with schwann cells, but no myelin sheath covers them
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unmyelinated axons in the CNS
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no association with oligodendrocytes
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Guillian-Barre Syndrome (GBS)
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autoimmune disease in which the body attacks Schwann cell membranes (PNS)
complete paralysis in a matter of days/weeks go to ICU, 80-90% complete resolution |
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regeneration only occurs in the _____. ______ play an active role in regeneration.
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PNS
Schwann cells |
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neurons at electrical synapses are joined by
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gap junctions
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at chemical synapses, the presynaptic neuron is separated from the postsynaptic neuron by:
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a synaptic cleft
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sensory (afferent) division
somatic sensory division |
from muscles, glands, etc. to CNS
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sensory (afferent) division
visceral sensory division |
from organs to the CNS
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motor (efferent) division
somatic motor division |
carries signals from CNS to skeletal muscles
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motor (efferent) division
visceral motor division (autonomic nervous system) |
carries signals from CNS to glands, cardiac muscle, and smooth muscle
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ANS divisions
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ANS = visceral motor division
sympathetic: arouses body for action parasympathetic: calms body |
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resistance _______ when ion channels are open, and ______ when they are closed
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increases when open
decreases when closed |
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the axon of the presynaptic neuron can synapse with ___________ of postsynaptic neuron
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dendrites and cell body
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neurotransmitter divisions
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acetylcholine: (excitatory or inhibitory, CNS or PNS)
amino acids: GABA; primary inhibitory neurotransmitter in brain monoamines: come from amino acids, are just modified..dopamine, norepinephrine..seratonin, histamine neuropeptides: short-chain amino acids..ex: beta-endorphins, cholecystokinin |
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T or F? a single EPSP is capable of causing the postsynaptic neuron to reach action potential
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False! EPSPs need to be added together (summation) to even think about getting to an action potential
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anterograde transport
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movement away from soma down the axon
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retrograde transport
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movement up the axon toward the soma
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an excitable membrane (on the axon) is usually what charge on the inside & outside?
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negative on the inside, positive on the outside.
reverses during action potential |
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current=
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VOLTAGE/resistance
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light nerve damage; how long for regeneration?
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35 days
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segment of neuron that receives signals from other neurons
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receptive segment
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what amino acid can cross the blood-brain barrier and is converted to seratonin in the brain?
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tryptophan
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