front 1 8)wWhich structural and functional type of neuron is activated first when you burn your finger? Which type is activated last to move your finger away form the source of heat? | back 1 first activated is unipolar (pseudounipolar) neurons that are sensory(afferent) neurons. The impulse to move your away from the heat will be carried by multipolar neurons that are motor (efferent) neurons. |
front 2 measure of potential energy generated by separated charge? Measured between two point. | back 2 voltage |
front 3 potential difference?
| back 3 voltage is always measured between two points
|
front 4 Open and closes in response to membrane potential?
| back 4 voltage-gated channels
|
front 5 electrical and concentration gradients constitute the
| back 5 electrochemical gradient
|
front 6 what are the 3 different neuron types | back 6 mutltipolar
|
front 7 which neuroon type are interneurons that conduct impulses within the CNS, initegrating sensory input or motor output; may be one of a chain of CNS neurons; some multipolar neurons are motor neurons that conduct impulses along the fferent pathways form the CNS to an effector (muscle/gland) | back 7 multipolar |
front 8 which neuron type are sensory neurons that are located in some special sense organs such as retina | back 8 bipolar |
front 9 which neuron type are sensory neurons that conduct impulses along afferent pathways to lthe CNS for interpretation. these sensory neurons are called primary or first-order sensory neurons | back 9 unipolar |
front 10 define resting membrane potential | back 10 potential diffference across the membrane of a resting cell -70mV in neurons (cytoplasmic side of membrane is negatively charged relative to outside) |
front 11 9)For an open channel,what factors determine in which direction ions will move through that channel? | back 11 The concentration gradient and the electrical gradient --- together called the elctrochemical gradient -- determine the direction in which ions flow through an open membrane channel. |
front 12 10)For which cation is there the greatest amount of leakage channels) across the plasma membrane? | back 12 there are more leakage of K+ than any other cations |
front 13 11)Comparing graded potentials and action potentials, which is bigger? Which travels farthest? Which initiates the other? | back 13 Action potentials are larger than graded potentials and travel furter. Graded potentials generally initiate action potential |
front 14 12)An action potential does not get smaller as it propagates along an axon. Why not? | back 14 an action potential is regenerated anew at each membrane patch. |
front 15 13) Why is conduction of action potentials faster in myelinated than in unmyelinated axons? | back 15 because myelin allows the axon membrane between nodes to change its voltage rapidly, and allows current to flow only at the widely spaced nodes |
front 16 14)If an axon receives two stimuli close together in time, only one AP occurs. why? | back 16 If a second stimulus occurs before the end of the absolute refractory period, no AP can occur because Na+ channels are still inactivated. |
front 17 15) What is the structure that joins two neurons at an electical synapse? | back 17 At an electical synapse, neurons are joined by gap junctions |
front 18 16)Events at a chemical synapse usually involve opening of both voltage-gated ion channels and chemically gated ion channels. Where are these ion channels located and what cause each to open? | back 18 Voltage-gated ion (Ca+) channels are found in the presynaptic axon terminal and open when an action potential reaches the axon terminal. Chemically gated ion channels are found in the postsynaptic membrane and open when neurotransmitter binds to the receptor protein. |