Term
| A difference in the concentration of charged particles between one point and another. |
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Definition
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Term
| Cellular mechanisms for producing electrical potentials and currents. |
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Definition
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Term
| A flow of charged particles from one point to another. |
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Definition
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Term
| Charge difference across the plasma membrane. |
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Definition
| Resting membrane potential (RMP) |
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Term
| RMP results from the combined effects of three factors: |
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Definition
1. Ions diffuse down their concentration gradient through the membrane.
2. Plasma membrane is selectively permeable.
3. Electrical attraction of cations and anions to each other. |
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Term
| K+ is about ___ times as concentrated in the ICF as in the ECF. |
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Definition
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Term
| ____ cannot escape due to size or charge (phosphates, sulfates, small organic acids, proteins, ATP, and RNA). |
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Definition
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Term
| Na+ is about ____ times as concentrated in the ECF as in the ICF. |
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Definition
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Term
| __% of the energy requirement is of the nervous system. |
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Definition
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Term
| Disturbances in membrane potential when a neuron is stimulated. |
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Definition
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Term
| Case in which membrane voltage shifts to a less negative value. |
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Definition
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Term
| Vary in magnitude with stimulus strength. |
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Definition
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Term
| Get weaker the farther they spread from the point of stimulation. |
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Definition
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Term
| Characteristics of local potentials |
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Definition
| Graded, decremental, reversible, either excitatory or inhibitory |
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Term
| More dramatic change produced by voltage-gated ion gates in the plasma membrane. |
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Definition
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Term
| Where an action potential is generated. |
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Definition
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Term
| A rapid up-and-down shift in the membrane voltage. |
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Definition
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Term
| Critical voltage to which local potentials must rise to open the voltage-regulated gates. |
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Definition
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Term
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Definition
1. If threshold is reached, neuron fires at its maximum voltage.
2. If threshold is not reached, it does not fire. |
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Term
| The period of resistance to stimulation. |
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Definition
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Term
| No stimulus of any strength will trigger an action potential. |
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Definition
| Absolute refractory period |
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Term
| Only especially strong stimulus will trigger a new action potential. |
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Definition
| Relative refractory period |
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Term
| A bundle of nerve fibers (axons) wrapped in fibrous connective tissue. |
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Definition
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Term
| A knotlike swelling in a nerve where neuron cell bodies are concentrated. |
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Definition
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Term
| The ____ carries sensory signals from various receptors to the CNS. |
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Definition
| Sensory (afferent) division |
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Term
| The ____ carries signals from receptors in the skin, muscles, bones, and joints. |
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Definition
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Term
| The ____ carries signals from the viscera of the thoracic and abdominal cavities. |
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Definition
| Visceral sensory division |
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Term
| The ____ carries signals from the CNS to gland and muscle cells that carry out the body's response. |
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Definition
| Motor (efferent) division |
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Term
| The ____ carries signals to the skeletal muscles. |
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Definition
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Term
| The ____ carries signals to glands, cardiac muscle, and smooth muscle. |
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Definition
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Term
| The ____ tends to have a calming effect and stimulates digestive and urinary systems. |
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Definition
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Term
| The ____ tends to arouse the body for action by accelerating heart beat and respiration. |
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Definition
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Term
| Universal properties of neurons |
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Definition
1. Excitability
2. Conductivity
3. Secretion |
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Term
| ____ neurons are specialized to detect stimuli and transmit information about them to the CNS. |
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Definition
| Sensory (afferent) neurons |
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Term
| ____ neurons lie entirely within the CNS and receive signals from many neurons and carry out the integrative function. |
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Definition
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Term
| 90% of all neurons are ____. |
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Definition
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Term
| ____ function means to process, store, and retrieve information and "make decisions" that determine how the body will respond to stimuli. |
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Definition
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Term
| ____ neurons send signals out to muscles and gland cells. |
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Definition
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Term
| The control center of a neuron |
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Definition
| Soma (neurosoma, cell body, or perikaryon) |
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Term
| The cytoplasm in a neuron contains: |
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Definition
| Mitochondria, Lysosomes, Golgi complex, some inclusions, rough ER, and cytoskeleton. |
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Term
| Dense mesh of mictrotubules found in the cytoskeleton; bundles of actin filaments. |
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Definition
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Term
| Golden brown pigment produced when lysosomes digest worn-out organelles. |
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Definition
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Term
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Definition
| Glycogen granules, lipid droplets, melanin, and lipofuscin |
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Term
| Vast number of branches coming from a few thick branches from the soma. |
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Definition
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Term
| An axon originates from a mound on one side of the soma called the ____. |
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Definition
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Term
| Branches of axon are called: |
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Definition
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Term
| A ____ neuron has one axon and multiple dendrites; the most common. |
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Definition
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Term
| Most neurons in the brain and spinal cord are: |
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Definition
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Term
| A ____ neuron has one axon and one dendrite. |
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Definition
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Term
| Most neurons in the olfactory cells, retina, and inner ear are: |
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Definition
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Term
| A ____ neuron has a single process leading away from the soma. |
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Definition
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Term
| Most neurons that participate in the sensory from skin and organs to the spinal cord are: |
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Definition
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Term
| A ____ neuron has many dendrites but no axon and helps in visual processes. |
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Definition
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Term
| Two-way passage of proteins, organelles, and other material along an axon. |
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Definition
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Term
| ____ is the movement down the axon away from the soma. |
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Definition
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Term
| ____ is the movement up the axon toward the soma. |
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Definition
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Term
| ____ guide materials along the axon. |
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Definition
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Term
| Motor proteins in anterograde transport |
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Definition
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Term
| Motor proteins in retrograde transport |
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Definition
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Term
| Fast anterograde transport moves: |
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Definition
| Organelles, enzymes, synaptic vesicles, and small molecules. |
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Term
| Fast retrograde transport moves: |
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Definition
| Recycled materials and pathogens---rabies, herpes, simplex, tetanus, and polio viruses. |
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Term
| Slow axonal transport is moves: |
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Definition
| Enzymes, cytoskeletal components, and new axoplasm down the axon during repair and regeneration of damaged axons. |
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Term
| Function of neuroglia or glial cells |
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Definition
1. Support neurons
2. Protect neurons
3. Bind neurons together and form a framework for nervous tissue
4. Guide migrating neurons to their destination (in fetus)
5. Prevents neurons from touching each other
6. Gives precision to conduction pathways |
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Term
| Neuroglia cells that form myelin sheaths in the CNS? |
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Definition
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Term
| Neuroglia cells that line internal cavities of the brain and secrete cerebrospinal fluid? |
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Definition
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Term
| Neuroglia cells that are macrophages and perform a complete checkup on the brain tissue several times a day. |
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Definition
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Term
| Most abundant glial cell in the CNS |
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Definition
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Term
| Astrocytes are found in the ____ matter of the CNS. |
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Definition
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Term
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Definition
1. Form a supportive framework of nervous tissue.
2. Have extensions (perivascular feet) that contact blood capillaries that stimulate them to form a tight seal called the blood-brain barrier.
3. Convert blood glucose to lactate and supply this to the neurons for nourishment. |
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Term
| Nerve growth factors are secreted by ____ to promote neuron growth and synapse formation. |
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Definition
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Term
| When a neuron is damaged, astrocytes from hardened scar tissue and fill space formerly occupied by the neuron. This is called: |
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Definition
| Astrocytosis or sclerosis |
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Term
| ____ cells envelope nerve fibers in the PNS, produce a myelin sheath, and assist in the regeneration of damaged fibers. |
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Definition
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Term
| ____ cells surround the neurosomas in the ganglia of the PNS, provide electrical insulation around the soma, and regulate the chemical environment of the neurons. |
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Definition
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Term
| Masses of rapidly dividing cells |
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Definition
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Term
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Definition
1. Meninges (protective membranes of CNS).
2. Metastasis from nonneuronal tumors in other organs.
3. Glial cells that are mitotically active throughout life. |
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Term
| ____ grow rapidly and are highly malignant. The blood-brain barrier decreases effectiveness of chemotherapy. Treatment consists of radiation or surgery. |
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Definition
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Term
| An insulating layer around a nerve fiber. |
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Definition
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Term
| In the PNS, ____ cells spiral repeatedly around a single nerve fiber. |
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Definition
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Term
| Thick, outermost coil of myelin sheath |
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Definition
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Term
| In the CNS, ____ reach out to myelinate several nerve fibers in its immediate vicinity. |
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Definition
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Term
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Definition
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Term
| Myelin-covered segments from one gap to the next. |
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Definition
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Term
| Short section of nerve fiber between the axon hillock and the first glial cell. |
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Definition
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Term
| Neurilemma wrapping of unmyelinated nerve fibers |
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Definition
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Term
| A degenerative disorder called ____ occurs when oligodendrocytes and myelin sheaths in the CNS deteriorate and are replaced by scar tissue. May be triggered by a virus. |
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Definition
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Term
| A degenerative disorder called ___ is hereditary and occurs when there is an abnormal accumulation o glycolipid called GM2 in the myelin sheath. |
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Definition
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