Term
| Functions of Nervous tissues |
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Definition
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Term
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Definition
| is composed of the brain and the spinal cord |
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Term
| Peripheral nervous system (PNS) |
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Definition
| Is composed of all other nervous tissue outside the CNS and includes sensory receptors and nerves |
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Term
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Definition
| Ending of nerve cells or separate, specialized cells that detect temperature, pain, touch, pressure and other stimuli. |
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Term
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Definition
| bundle of axons and their sheaths |
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Term
| Functional divisions of the nervous system |
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Definition
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Term
| Charasteristics of the afferent division |
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Definition
| is the sensory division, transmitts action potential to the CNS from sensory receptors |
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Term
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Definition
| is the motor division, transmitts action potential away from the CNS to effector organs |
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Term
| Division of the efferent division |
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Definition
| Somatic Nervous system and automatic nervous system |
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Term
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Definition
| transmitts action potential from the CNS skeletal muscle under voluntary control |
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Term
| Sympathetic nervous system |
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Definition
| Active during physical activity, responsible for the "fight or flight" response. |
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Term
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Definition
| Transmits action potentials from the CNS to cardiac muscles, smooth muscles and glands. function under involuntary control it is further divided into the sympathetic, parasympathetic and entric nervous systems |
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Term
| Parasympathetic nervous system |
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Definition
| Regulates resting functions such as digeting food or emptying urinary bladder. " rest & digest" |
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Term
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Definition
| Located in the digestive tract and it controls the digestive tract independently from the CNS |
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Term
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Definition
| A decrease in membrane potential |
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Term
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Definition
| An increase in membrane potential |
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Term
| what are two methods of propagation? |
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Definition
| -Continuous propagation: Unmyelinated axons |
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Term
| Steps in continuous propagation |
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Definition
| -Affects one segment at the time |
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Term
| Charactristics of Saltatory propagation |
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Definition
| -Acion potential along myelinated axon |
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Term
| factors that affect speed of propagation |
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Definition
| -Ion movement is related to cytoplasm concentration |
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Term
| Characteristics of type A fibers |
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Definition
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Term
| Characteristics of Type B fibers |
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Definition
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Term
| Characteristics of Type C fibers |
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Definition
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Term
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Definition
| Action potentials that are transmitted from presynaptic neuron to postsynaptic cells across a synapse |
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Term
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Definition
| -Are locke together at gap junctions |
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Term
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Definition
| -Are found in most synapses between neurons and all synapses between neurons and other cells |
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Term
| Exciatory neurotransmitter |
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Definition
| Causes depolarization of postsynaptic membranes, promote action potential |
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Term
| Inhibitory Neurotransmitter |
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Definition
| Causes hyperpolarization of postsynaptic membranes, supress action potentials |
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Term
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Definition
| Substances released from neurons that can presynaptycally or post synaptically influece the likelyhood that an action potential will be produced in the postsynaptic cell. |
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Term
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Definition
| A neuron that recieves many IPSPs is inhibited from producing an action potential because the stimulation needed to reach the threshold is incressed |
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Term
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Definition
| To triger an action potential one EPSP is not enough, EPSP and IPSP combine through sumation |
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Term
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Definition
| Multiple times, rapid repeated stimuli at one synapse |
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Term
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Definition
| Multiple locations, many stimuli arrive at multiple synapses |
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Term
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Definition
| Synapses between the axaons of two neurons |
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Term
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Definition
| Many neurons converge and synapse with a smaller number of neurons. Allows for diffrent parts of the nevous system to activate or inhibit the activity of neurons |
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Term
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Definition
| A smaler ammount of presynaptic neurons synapse with a larger number of postsynaptic neurons. Allows for one part of the nervous system to affect more than one other part of the nervous system |
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Term
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Definition
| Have neurons arranged in a circular fashion, simililar to the possitive feedback mechanisim |
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Term
| Initial stimulus threshold of an Action Potential |
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Definition
| A graded depolarization of the axn hillock large enough (10-15mV) to change the resting potential. |
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Term
| Depolarization phase of an action Potential |
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Definition
| Activation phase of voltage-gated Na+ channels. Rapid Depolarization, Na+ ions rush into cytoplasm, inner membrane changes from negative to possitive. |
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Term
| Repolarization phase of an action potential |
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Definition
| Inactivation of Na+ channels, activation of K+ channels. happens at +30Mv. Inactivation gate closes, Voltage gated K+ channels opens, Repolarization begins. |
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Term
| After potential of action potentials |
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Definition
| K+ channels begin to close when membrane reaches normal resting potential (-70mV). After the K+ channels finish closing, membrane is Hyperpolarized to -90mV, then transmember potential retuns to resting level, action potential is over |
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Term
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Definition
| Last from the begining of the action potential to the return to the resting state during which a membrane will not respond normally to any additioanal stimuli |
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Term
| Absolute Refractory period |
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Definition
| Sodium channels are open or innactive, no action potential is possible |
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Term
| Realtive Refractory Period |
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Definition
| Membrane potential is almost normal, a very large stimulus can generate an action potential |
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Term
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Definition
| Produces a graded potential not strong enough to reach the treshold, no action potential is produced |
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Term
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Definition
| Just strong enough to produce the maximum frequency of action potentials |
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Term
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Definition
| produces a graded poteintial just strong enough to reach threshold and cause an action potential |
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Term
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Definition
| All stimulus between the threshold and the maximal stimulus straength. action potential frequency increasses in proporation to the strenght of the stimulus |
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Term
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Definition
| any stimulus stronger than the maximal stimulus, cannot produce a faster action potential frequency beacuse max frequncy has already been met. |
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