ASU BIO 181 Exam 3 Study Guide questions with complete solutions

When the presynaptic cell contacts a muscle cell, the synapse area is called a motor end plate. correct answer: TRUE Briefly explain why the action potential flows only from the axon hillock to the terminal web. correct answer: During the course of an action potential there is a refractory period that makes sure the action potential can't trigger backwards by the use of caps on gated sodium channels. The caps close and keeps the action potential flowing in one direction. How do the glial cells (i.e., myelin sheath) speed up the firing of neurons? correct answer: Glial cells allows the chemistry of the axon of neurons to jump down the axon instead of having to happen at every micrometer of the length of the axon. Voltage-gated ion channels open when a protein binds to the receptor. correct answer: FALSE The action potential is: correct answer: A result of the movement of ions The central nervous system (CNS) contains: correct answer: No correct Answers Receptors are made from membrane-bound polyribosomes. correct answer: TRUE List the 4 types of glial cells and list a phrase to describe their function. correct answer: Schwann cells -wraps around axons of neurons in peripheral nervous system, providing electrical insulation Oligodendrocytes - similar function for axons in CNS Astrocytes - contribute to blood-brain barrier, protects the brain from toxic chemicals Microglia - part of cellular immune system to protect brain The resting potential of neurons is: correct answer: The answer is not on this list Excitatory synapses cause hyperpolarization of post-synaptic cells. correct answer: FALSE Fast neurons as described in lecture are fast because they are surrounded by a type of glial cell that results in a myelin coating. correct answer: FALSE The cell body refers to the part of the neurons that begin at the dendrites and extend to the axon terminal. correct answer: FALSE Fast neurons as described in lecture require cytoplasmic signal transduction to open an ion channel. correct answer: FALSE Draw an action potential in the axon of a neuron and indicate which ions flow into the neuron and out of the neuron as the action potential passes at the point where the electrodes are in the cell. Be sure to assign on the Y-axis the mV of each of these areas. This should be as described in my lectures. correct answer: