1. a. The action potential changes the membrane potential from -70 mV (resting) to +30 mV and back again to the resting membrane potential. b. This results from a change in membrane permeability first to Na then to K due to the opening of what type of ion channels? Voltage gated channels 2. a. Where is the density of voltage-gated Na+ channels the greatest? Axon hillock b. What areas of the neuron generate signals that open these voltage-gated channels? Dendrites and the cell body c. Opening
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The action potential is started when the membrane is very slightly ‘depolarised’‚ meaning that the charges inside and outside the cell become more similar. This happens when a stimulus causes a small influx of sodium ions into the cell. For an action potential to occur‚ the voltage has to pass a threshold value of -58mV. at this point‚ in a cycle of positive feedback‚ the action potential will always occur. Once the threshold value has been reached
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different electrode sites. The amplitude and the shape of the signals depend upon the position of the electrodes (Brown‚ 1999) (Conover‚ 1992). The SA node produces the pacemaker potential and if this reaches the threshold then an action potential is generated. There are five stages involved during cardiac action potentials‚ during these stages there is a flow of ions through
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When a ball is dropped/ thrown to the ground‚ gravity forces the ball to move downwards‚ whilst the ball falls down‚ the Gravitational Potential Energy (GPE) that the ball has transforms into Kinetic energy. As the ball hits the ground with maximum Kinetic energy‚ the forces in play flatten and deform the frame/shape of the ball by compressing and dispersing the molecules that essentially make up the ball. As stated in the law of conservation energy‚ energy can neither be created nor destroyed; rather
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applying a net force‚ the object speeds up and thereby gains kinetic energy(Kinetic Energy) which will make my car go further. This illustrates how if there is more potential energy than kinetic energy the car won’t go nearly as far as it could. According to my research‚ potential energy is stored energy that is waiting to be used(Potential Energy)‚ so that means
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second power. What is potential energy? Some objects have stored energy as a result of their positions or shape.Potential energy is stored energy that results from the position or shape of an object. What is gravitational potential energy? Potential energy related to an object’s height is called gravitational potential energy. An object’s gravitational potential energy depends on its way and on its height relative to a reference point. To find gravitational
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Chapter 6 Resting Membrane Potential (RMP) What is the Resting Membrane Potential (RMP)? ELECTRIC POTENTIAL – separation of opposite charges between 2 points. (“Has the potential to do electrical work if allowed to come together!”) vs. large potential difference small potential difference Magnitude of charge separation = potential difference ** measured in volts (1 Volt
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membrane changes its electric potential. In other words‚ how is the cell membrane excited? At the surface of the cell membrane‚ there are three classes of gated channels exist‚ chemically gated or ligand-gated channels‚ voltage-gated channels‚ and mechanically gated channels. Originally‚ at the resting membrane potential‚ most of the gated channels are closed. However‚ when these gated channels open‚ the movement of ions across the membrane will changes the membrane potential. In the nervous system‚ the
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Name: Christina Hale Exercise 3: Neurophysiology of Nerve Impulses: Activity 4: The Action Potential: Importance of Voltage-Gated Na+ channels Lab Report Pre-lab Quiz Results You have not completed the Pre-lab Quiz. 02/28/15 page 1 Experiment Results You have not completed the Experiment. Experiment Data: 02/28/15 page 2 Post-lab Quiz Results You have not completed the Post-lab Quiz. 02/28/15 page 3 Review Sheet Results 1. What does TTX do to voltage-gated Na+ channels? Your answer: It
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Activity 4: Generation of Action Potentials Name: Instructor: Date: PREDICTIONS 1. Exceeding the threshold depolarization at the trigger zone DECREASES the likelihood of generation of action potential. 2. Action potential amplitude: DOES NOT CHANGE with distance 3. Increasing frequency of stimulation to the trigger zone: DOES NOT increase the production of action potentials. MATERIALS AND METHODS Experiment 1: Effect of Stimulus Strength on Action Potential Generation 1. Dependent Variable
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