Neurophysiology of Nerve Impulses
What is the effect of axon diameter on the conduction velocity? 45. What is the effect of the amount of myelination on conduction velocity? 46. Why did the time between stimulation and the action potential at R1 differ for each axon? ACTIVITY 8: Chemical Synaptic Transmission and Neurotransmitter Release 47. The synapse is the location where the axon of one neuron communicates with a. another neuron. b. a muscle fiber. c. a sensory receptor. d. any or all of the above. 48. Neurotransmitter is released into the synaptic gap by a process called a. secretion. b. excretion. c. exocytosis. d. iffusion. 49. The name of the specific neurotransmitter released at a synapse between a motor neuron and a muscle cell is ____________. 50. When the stimulus intensity is increased, what changes: the number of synaptic vesicles released or the amount of neurotransmitter per vesicle? 51. What happened to the amount of neurotransmitter released when you switched from the control extracellular fluid to the extracellular fluid with no Ca2+? 52. What happened to the amount of neurotransmitter released when you switched from the extracellular fluid with no Ca2+ to the extracellular fluid with low Ca2+?
ACTIVITY 9: The Action Potential…Putting It All Together 53. True or False: The amplitude of the depolarization that can result at the postsynaptic receptor is always the same. 54. In this simulation, when the sensory neuron membrane potential at the receptor was -40mV, the interneuron membrane potential at the “receiving end” was ______ mV. 55. In this simulation, with a “strong stimulus”, _____ sensory neuron vesicles were released from the axon terminal. a. many, many b. 15 c. 10d. 6 56. Describe what happened when you applied a very weak stimulus to the sensory receptor, i. e. as there an action potential? How many vesicles were released? 57. Describe what happened when you applied a moderate stimulus to the sensory receptor, i. e. was there an action potential? How many vesicles were released? 58. Identify the type of membrane potential (graded receptor potential or action potential) that occurred at R1, R2, R3, and R4 when you applied a moderate stimulus. (Compare/view the response to the stimulus. ) 59. Describe what happened when you applied a strong stimulus to the sensory receptor. What type(s) of membrane potential were caused? Were the responses at R1 through R4 all the same?