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Definition
| Neurons, muscle cells, sensory receptor cells, gland cells |
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Definition
| An axon is stimulated, and electrical impulse is generated and conducted along the length of its axon. |
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Definition
| The electrical part of a nerve impulse |
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Definition
| the measure of potential energy, generated by seperated charge |
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Term
| How is potential energy measured |
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Definition
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Term
| The greater the potential difference between two points, the ______ the voltage |
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Definition
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Definition
| the flow of electrical charge from one point to another |
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Term
| The amount of charge that moves between two points depends on _____ and ______ |
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Definition
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Term
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Definition
| is the hindrance to charge flow provided by substances through which the current must pass |
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Definition
| substance with high electrical resistance |
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Definition
| substance with low electrical resistance |
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Term
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Definition
| gives the relationship between voltage, current and resistance |
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Term
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Definition
I = V/R ; considering that conductance (g) is the inverse of resistance (1/R), I = V g
The greater the voltage, the greater the current; the greater the conductance, the greater the current; and, if there is no voltage (V = 0), then there is no current. |
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Term
| Examle of an excellent insulator |
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Definition
| lipid bilayer of the plasma membrane |
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Term
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Definition
special membrane proteins
large proteins with several subunits |
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Term
| Three main types of gated channels |
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Definition
| Chemically gated, voltage gated, mechanically gated |
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Term
| Chemically gated channels |
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Definition
| opens when approriate chemical substance binds to a certain part of the ion channel (neurotransmitters) |
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Term
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Definition
| Open and close in response to changes in the membrane potential |
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Term
| Mechanically gated channels |
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Definition
| open in response to mechanical deformation of the plasma membrane |
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Term
| Ions move along chemical concentration gradient when they |
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Definition
| diffuse passively from an area of higher concentration to lower concentration |
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Term
| Ion moves along electrical gradient when they |
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Definition
| move towards an area of opposite electricity |
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Term
| The Na+ concentration is higher on the ________ of the cell |
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Definition
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Term
| The K+ concentration is higher on the_____ of the cell |
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Definition
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Term
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Definition
| A reduction in membrane potential; the inside of the membrane becomes less negative |
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Term
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Definition
| An increase in membrane potential; becomes more negative than the resting potential. |
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Term
| Depolarization _____ the probability of producing action potentials |
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Definition
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Term
| Two types of signals produced with change in membrane potential |
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Definition
| Graded and action potential |
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Term
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Definition
| magnitude varies directly with stimulus strenght. The stronger the stimulus, the more voltage change and the farther the voltage change goes |
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Term
| Types of Graded Potential |
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Definition
| end-plate potential, postsynaptic potential, receptor or generator potential |
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Definition
| is a type of graded potential which is at the end plate zone of a skeletal muscle fiber |
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Definition
| when the stimulus is the neurotransmitter released by another neuron at the zone of physiological interaction b/w 2 neurons |
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Term
| Receptor or generator potential |
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Definition
| at the receptor end of a sensory receptor cell |
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Term
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Definition
| the principle way neurons send signals over long distance is by generating and propogating action potentials |
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Term
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Definition
| the transition from graded potential to action potential takes place here in motor spinal neuron |
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Term
| In sensory neurons, the action potential is generated by |
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Definition
| receptor potential at the end of the peripheral axonal process |
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Term
| Each Na+ channels has _____ gates |
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Definition
| 2: voltage-sensitive activation gate and an inactivation gate |
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Term
| During Resting state of action potential |
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Definition
| only leakage channels are open, maintaining the resting membrane potential |
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Term
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Definition
| a sudden increase in Na permeability and reversal of the membrane potential |
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Term
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Definition
| decrease in sodium permeability |
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Term
| Absolute Refactory Period |
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Definition
| period that extends from the opening of the Na channels until they begin to reset to their original resting state |
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Term
| Relative Refactory Period |
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Definition
| Interval in which most Na channels have returned to their resting state and some K channels are still open |
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Term
| Absolute Refactory Period |
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Definition
| period that extends from the opening of the Na channels until they begin to reset to their original resting state |
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Term
| Relative Refactory Period |
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Definition
| Interval in which most Na channels have returned to their resting state and some K channels are still open |
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Term
| The rate of impulse propogation depends on |
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Definition
| axon diameter and degree of myelination |
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Term
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Definition
| axons are unmyelinated and action potentials are generated at adjacent to each other and propogation speed is slow |
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Term
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Definition
| Action potentials are triggered only at nodes of ranvier |
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Term
| Nerver fibers can be classified based on |
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Definition
| degree of myelination, and conduction speed into groups A, B, C |
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Term
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Definition
| has largest diameters and thick myelin sheaths, with propgation speed up to 120 m/s. Mostly sensory somatic and motor axons serving the skin, skeletal muscles and joints |
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Term
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Definition
| lightly myelinated axons of intermediate diameter, speed of around 15 m/s |
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Term
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Definition
unmyelinated with smallest diameter, speed of 1 m/s or less.
Axons of ANS and those conveying info about pain & temperature related to A&B |
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