into the bloodstream of the patient‚ the K+ gradient across the membrane is reduced. This results in depolarization where cells generate an action potential. Voltage-gated Na+ channels open in response to depolarization and close by inactivation for a refractory period and remain closed until repolarization. In this new setting‚ less K+ leaks out of the intracellular space and the cell is unable to return to its resting membrane potential (ie. The cell stays slightly depolarized) as the voltage-gated
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Activity 1: The Resting Membrane Potential Pre-lab Quiz Results 1. What is the approximate concentration of K+ inside a typical cell (intracellular concentration)? a. 150 mM 2. What is the approximate concentration of K+ outside a cell (extracellular concentration)? b. 5 mM 3. What is the approximate concentration of Na+ inside a cell (intracellular concentration)? b. 5 mM 4. What is the approximate concentration of Na+ outside a cell (extracellular concentration)? a. 150 mM Experiment
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increasing extracellular K+ causes the membrane potential to change to a less negative value. How well did the results compare with your prediction? Your answer: If extracellular K+ is increased then the intracellular K+ will decrease. Fewer intracellular K+ ions would result in the membrane potential being less negative. This is what I predicted to happen. 3. Explain why a change in extracellular Na+ did not significantly alter the membrane potential in the resting neuron? Your answer: There
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Neurophysiology of Nerve Impulses ACTIVITY 1 The Resting Membrane Potential 1. Explain why increasing extracellular K+ reduces the net diffusion of K+ out of the neuron through the K+ leak channels. If the extracellular K+ increases then the concentration of intracellular K+ will decrease causing a decrease in the steepness of the concentration gradient and fewer K+ ions would be drawn out. 2. Explain why increasing extracellular K+ causes the membrane potential to change to a less negative value. How well
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Activity: Action Potentials Name: Barbara Uthe Instructor: Catherine Rice Date: 08.17.2014 Predictions Exceeding threshold depolarization at the trigger zone______the likelihood of generation of an action potential. increases Action potential amplitude increases with distance Increasing frequency of stimulation to the trigger zone decreases number of action potentials Materials and Methods Experiment 1: Effect of Stimulus Strength on Action Potential Generation Dependent
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table. Discussion: In the experiment‚ I believe the phenomenon to take place is osmosis. Osmosis is the movement/diffusion of water molecules through a selectively permeable membrane from an area of high concentration of water molecules (high water potential) to an area of a low concentration of water molecules (low water potential). From previous knowledge I know when a plant cell is put into a solution with the same concentration as the cell contents‚ this is referred to as isotonic‚ some water molecules
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singal integration‚ it consists of the axon hillock. The signals transmitted from the first zone is integrated in this region. If the signal is strong enough‚ an action potential would be initiated. Third zone is specialized for signal conduction‚ it consists of the axon. The axon carries the information‚ usually from action potentials‚ from the cell body to the axon terminal. The fourth zone of a neuron is for signal transmission to target cells‚ it consists of the axon terminals. These axon terminals
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and/or from the CNS and visceral organs or structures of the body periphery (Marieb & Mitchell‚ 2009). In this experiment we will work with a nerve The action potential we will see on this experiment reflects the cumulative action potentials of all the neurons in the nerve‚ called a compound nerve action potential. Although an action potential follows the all-or none law within a single neuron‚ it does not necessarily follows the all-or-none law within an entire nerve. When you electrically stimulate
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system. The entire respiratory tract in lined with a mucus membrane that collects foreign particles. Once the mucus‚ or airway surface liquid (ASL) traps particles‚ mucus clearance is an essential mechanism to remove the foreign particles‚ such as dust‚ bacteria‚ viruses and other potential pathogens‚ and to keep our airways and lungs clean and free of obstruction. An important mechanism for clearing mucus involves moving water across the membrane‚ out of the cell‚ into the mucus. This movement of water
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irritability‚ conductivity‚ resting membrane potential‚ polarized‚ sodium-potassium pump‚ threshold stimulus‚ depolarization‚ action potential‚ repolarization‚ hyperpolarization‚ absolute refractory period‚ relative refractory period‚ nerve impulse‚ compound nerve action potential‚ and conduction velocity. 2. To list at least four different stimuli capable of generating an action potential. 3. To list at least two agents capable of inhibiting an action potential. 4. To describe the relationship between
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