Term
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Definition
| nerve cells that respond to physical or chemical changes in their surroundings |
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Term
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Definition
| extensions on neuron that receive the stimuli |
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Term
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Definition
| carries nerve impulse away from cell body of neuron |
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Term
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Definition
| space between axon of 1 neuron and dendrites of another neuron |
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Term
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Definition
| a neuroglial cell in PNS that wraps itself around axons |
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Term
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Definition
| fatty substance made by schwann cells to insulate parts of the axon from impulses |
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Term
| white, faster, motor neurons |
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Definition
| What are characteristics of myelinated axons? |
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Term
| unipolar, bipolar, multipolar |
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Definition
| What are the structural neuron groups? |
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Term
| sensory, motor, interneurons |
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Definition
| What are the 3 functional neuron groups? |
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Term
| Sensory (afferent) neurons |
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Definition
| What are the neurons that carry info. to the brain? |
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Term
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Definition
| What are the neurons that carry info. from brain out to the effectors (muscles and glands)? |
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Term
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Definition
| neurons in brain or spinal cord that link neurons together. |
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Term
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Definition
| a disease where myelin becomes inflamed due to autoimmune responses and the myelin deteriorates and forms scar tissue. Impulses are impaired. |
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Term
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Definition
| They support neurons structurally support and nutrition for neurons; help create blood brain barrier. |
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Term
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Definition
| provides myelin on several axons in CNS |
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Term
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Definition
| phagocytize bacteria and debris in CNS |
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Term
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Definition
| create lining around the brain and ventricles |
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Term
| 1. Distal severed axon deteriorates leaving only the neurilemmal sheath of the Schwann cells behind 2. Proximal end of axon sprouts and is guided towards the effector by the neurilemmal sheath. 3. Schwann cells proliferate on new sprouted axon |
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Definition
| What are steps of nerve regeneration? |
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Term
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Definition
| excess myelin impairs NS function. Myelin accumulates b/c of a missing lysosomal enzyme. Death occurs by age 4. |
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Term
| Central Nervous System b/c oligodendrocytes don't have neurilemma and they don't proliferate after injury. |
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Definition
| Where is nerve regeneration very unlikely to occur? |
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Term
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Definition
| Neuron that brings impulse to synapse |
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Term
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Definition
| stores neurotransmitter in synaptic knobs |
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Term
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Definition
| When impulses jump from node to node on myelinated axons, speeding up the impulse. |
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Term
Calcium, Ca +
A deficiency may cause muscle spasms. |
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Definition
| What ion is required to close Na+ channels? |
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Term
Anesthetics
Ex. Procaine, Novocaine |
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Definition
| These decrease membrane permeability to Na+ on touch and pain neurons. |
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Term
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Definition
| Which nerves are the fastest? |
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Term
| Inhibitory neurotransmitters |
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Definition
| Neurotransmitters that increase permeability to K+ outside neuron and hyperpolarize the membrane |
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Term
| Excitatory Neurotransmitters |
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Definition
| Neurotransmitters that bind to receptors that open Na+ channels, so Na+ diffuses into the neuron |
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Term
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Definition
| The initial part of the axon where summation of all the stimuli is "summed up" together to determine if threshold is reached. |
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Term
| 1. Action potential along axon causes axon to be more permeable to Ca+ and Ca rushes into axon. 2. Ca+ causes synaptic vessicles to migrate to end of knob 3. Vessicles dump neurotransmitter into the cleft. |
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Definition
| What are the steps leading to neurotransmitter release? |
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Term
| enzymes destroy neurotransmitter or reuptake of neurotrans. into vessicles. |
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Definition
| How is the neurotransmitter's effects on the postsynaptic membrane stopped? |
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Term
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Definition
| When neurotransmitters are removed from synaptic cleft and put back in syn. vessicles to stop an impulse. |
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Term
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Definition
| Name two natural painkillers made by the body. |
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Term
| acetylcholine, epinephrine, glutamate, histamine |
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Definition
| Name 3 excitatory neurotransmitters |
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Term
| dopamine, GABA, serotonin |
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Definition
| Name 3 inhibitory neurotransmitters |
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Term
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Definition
| What's the neurotransmitter that excites skeletal muscles? |
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Term
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Definition
| What disease is caused by a dopamine deficiency? |
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Term
1. block binding site for neurotransmitter
2. block reuptake of neuro.
3. block synthesis or release of neurotrans. |
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Definition
| List several ways that conduction across a synapse can be interrupted. |
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Term
| The inside is negatively charge compared to the outside. The charge difference is -70 mv |
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Definition
| Describe a resting neuron. |
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Term
| Na+ outside cell membrane; K+ and Cl- are inside cell membrane |
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Definition
| Where are Na+, K+ and Cl- ions in most numerous in the neuron? |
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Term
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Definition
| What't the minimum stimulus needed to reach an action potential? |
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Term
| Neurons are excitable. That means the dendrites become more permeable to Na+ if their stimuli is presnet. If enough Na+ enters to depolarize the membrane to -55mv, an action potential will start |
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Definition
| HOw is threshold reached? |
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Term
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Definition
| What maintains a polarized membrane in a resting neuron? |
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Term
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Definition
| What is a membrane called that is more negative than the resting potential? |
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Term
| An action potential begins |
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Definition
| What happens when threshold is reached? |
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Term
| Depolarization and Repolarization |
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Definition
| What are the two events in an action potential? |
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Term
| Na+ rushing into the cell membrane |
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Definition
| What depolarizes the neuron? |
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Term
| K+ rushing out of the cell membrane |
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Definition
| What repolarizes the cell membrane? |
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Term
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Definition
| What is a wave of action potentials called? |
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Term
| If threshold is reached an impulse will travel down the entire axon and all impulses are of the same strength. |
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Definition
| What is the all or none response? |
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Term
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Definition
| the brief time after a nerve impulse where another impulse won't be able to start. |
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Term
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Definition
| A greater intensity stimulus produces _____ impulses/ second |
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