4. Which part of the neuron was stimulated? Action potential is first generated in the dendrites of the neuron, or where the neuron receives the action potential of other neurons.…
Electrical, mechanical, thermal, and chemical stimulation are all capable of generating an action potential in a nerve.…
|Action potential |A brief reversal of the resting potential across the cell surface membrane of a neurone. All action |…
Virtual Lab Stimulation Exercise 3 Activities 1-5 Study online at quizlet.com/_cfevi 1. 2. 3. 4. 5.…
When muscle cells begin to repolarize, first the acetychloine is removed from the receptors on the cells. This in turn causes the receptor mediated Na+ leak channels to close. Voltage gated potassium leak channels open as a result. As K+ ions begin coming into the cytoplasm to repolarize. When the membrane potential reaches a specific level, the voltage gated potassium leak channels close as well. The sodium potassium pump works throughtout this process, by pumping Na+ ions out and K+ ions into the cells (using ATP, by a process called active transport).Ca2+ ions are pumped back into the SR by means of active transport. The membrane potential is then restored to the resting potential of…
Discuss the relative permeability of the membrane to Na+ and K+ in a resting neuron.…
Why do sodium ions need channels in order to move into and out of cells?…
“(3) Specific enzymes that drive active pumps that promote concentration of certain ions, particularly potassium (K+), within the cell while keeping concentrations of other ions, for example sodium (Na+), below concentrations found in the extracellular environment…” (McCance &Huether, pg. 12).…
Pores are ion-specific and provide free access to their respective ions across the plasma membrane. Ions move through these pathways via diffusion – down their concentration gradient.…
Discuss the relative permeability of the membrane to Na+ and K+ in a resting neuron.…
Experiment Results Predict Question: Predict Question: Predict what will happen to the resting membrane potential if the extracellular K+ concentration is increased. Your answer : b. The resting membrane potential will become less negative. Stop & Think Questions: What is the polarity of the resting membrane potential (voltage)? You correctly answered: b. negative What does it mean that the voltage just inside the membrane is negative? You correctly answered: b. There are more negative charges than positive charges just inside the membrane. The membrane of most cells, including neurons, contains passive, open, K+ leak channels. Given the normal K+ concentrations and the resultant concentration gradient, which direction would K+ be expected to move (diffuse) through these leak channels? You correctly answered: b. out of the cell What effect does increasing extracellular K+ have on the net diffusion of K+ out of the cell? You correctly answered: b. It decreases the net diffusion of K+ . Which way would Na+ move across the membrane if there were open Na+ channels? You correctly answered: a. Na+ would diffuse into the cell. The membrane has open K+ channels, and changing extracellular K+ concentration results in a change in membrane potential. Changing the extracellular Na+ concentration does not significantly change the membrane potential. What do your results suggest about the number or state (open or closed) of Na+ channels in the resting membrane of a neuron? You correctly answered: b. Na+ channels are mostly closed. Experiment Data: Extracellular Fluid (ECF) Control Control Control Control High K+ High K+ High K+ High K+ Low Na+ Low Na+ Low Na+ Low Na+ Microelectrode Position Cell body extracellular Cell body intracellular Axon extracellular Axon intracellular Axon intracellular…
C. Sodium conductance has a sharp spike (almost vertical line to a steady decline, reaching a top of approximately 0.034), however potassium (which peaks at 0.013) is a gentle rise and decline. Sodium conductance peaks at the same time as the membrane voltage. The potassium conductance begins to increase at about 0mV. The sodium conductance begins to increase at -34mV. Sodium movement is much higher at the beginning. Potassium is gradual from middle to end.…
a. What acts as a chemical force that pushes K+ out of the cell? ___________…
vii. Electrical signal along a nerve cell triggers a chemical release across a synapse to trigger response…
NERVOUS SYSTEM OUTLINE I. Nervous System = 2 Parts A. Central Nervous System (CNS) 1. Brain 2. Spinal Cord B. Peripheral Nervous System (PNS) 1. Nerves to parts of the body 2. Nerves from parts of the body C. Functions 1.…