PNB 2264 Final Exam With 100% Correct Answers 2024/2025

PNB 2264 Final Exam With 100% Correct Answers 2024/2025 Which of the following are responsible for the relaxation phase of muscle twitch? -the ryanodine receptor (RyR) -SERCA -DHP - answerSERCA Increasing intensity of a pressure stimulus (applied to the same spot on your finger) is coded by ____ (assume threshold is met) -increasing amplitude of receptor potential -increasing frequency of afferent action potentials at first node of ranvier -increasing frequency of afferent action potential of axon terminal -all of the above - answerall of the above with respect skeletal muscle contraction: -a single motor neuron can innervate multiple muscle fibers -at any given time, the sarcoplasmic reticulum contains a high concentration of calcium, or zero calcium -every muscle fiber in a particular muscle group (bicep) contracts together -a muscle fiber can be innervated by multiple neurons - answera single motor neuron can innervate multiple muscle fibers which of the following will change the permeability of the membrane to chloride -glutamate opening a ligand gated chloride channel -the action potential -changing ECl from -54mV to +30mV -all of the above - answerglutamate opening a ligand gated chloride channel during the power stroke phase -all of the above -ATP binds to myosin -actin moves -ATP and phosphate are bound to myosin - answeractin moves T-Tubules: -contain sarcomeres -store calcium ions -store oxygen to provide muscle with a constant supply of ATP -propagate the action potential - answerpropagate the action potential during the rise of the action potential: -sodium permeability is increasing -potassium permeability is zero -the inactivation gate is closed -all of the above - answersodium permeability is increasing myelinated axon segments are referred to as _____. Local currents travel _____ through these segments -internode, faster -node, faster -node, slower -internode, slower - answerinternode, faster which of the following is not a characteristic of neurons? -high metabolic rate -long life span -long length -mitosis - answermitosis you are interested in studying a cell under conditions where it is selectively permeable to chloride and potassium ions, but not to sodium ions. In order to look more closely at the electrical properties of the cell, you would need to perform calculations using: -the GHK equation -the nernst equation -fick's law - answerthe GHK equation in a typical neuron, the density of voltage gated channels is highest in the -dendrites -node -internode -axon hillock - answeraxon hillock in contrast to potentials developed at the motor end plate, synaptic potentials on dendrites are often -graded potentials -IPSPs -produced by voltage gated channels -due to neurotransmitter binding - answerIPSPs rapid dystonia parkinsonism results from a m