Ch. 48-49 Nervous System 9e S13
... Membrane Potential: difference in electrical charge across cell membrane ...
... Membrane Potential: difference in electrical charge across cell membrane ...
axonal terminals
... • The refractory period is when the Na+ and K+ are returned to their original sides: Na+ on the outside and K+ on the inside. • While the neuron is busy returning everything to normal, it doesn't respond to any incoming stimuli. • After the Na+/K+ pumps return the ions to their rightful side of the ...
... • The refractory period is when the Na+ and K+ are returned to their original sides: Na+ on the outside and K+ on the inside. • While the neuron is busy returning everything to normal, it doesn't respond to any incoming stimuli. • After the Na+/K+ pumps return the ions to their rightful side of the ...
Document
... Graded potentials are caused by the activation of gated ion channels. – closed in normal resting cells – chemical- or ligand-gated channels Summation is the ability of graded potentials to combine. ...
... Graded potentials are caused by the activation of gated ion channels. – closed in normal resting cells – chemical- or ligand-gated channels Summation is the ability of graded potentials to combine. ...
Nervous System
... o Domino affect = one Na+ opening triggers the next and so on… causes membrane potential increases to +35 mV (outside = - ; inside = +) • all or none principle: all the way to +35 mV or not o So long as they can reach the threshold of the cell, strong stimuli produce no stronger action potentials ...
... o Domino affect = one Na+ opening triggers the next and so on… causes membrane potential increases to +35 mV (outside = - ; inside = +) • all or none principle: all the way to +35 mV or not o So long as they can reach the threshold of the cell, strong stimuli produce no stronger action potentials ...
Membrane potential
... • Fluid just outside cell is more negatively charged than fluid inside • Potential is measured in millivolts • Resting potential is usually about -70mv ...
... • Fluid just outside cell is more negatively charged than fluid inside • Potential is measured in millivolts • Resting potential is usually about -70mv ...
Lecture Slides - Austin Community College
... When gated ion channels open, ions diffuse across the membrane following their electrochemical gradients. This movement of charge is an electrical current and can create voltage (measure of potential) energy change across the membrane. This electrical charge across the membrane is the membrane poten ...
... When gated ion channels open, ions diffuse across the membrane following their electrochemical gradients. This movement of charge is an electrical current and can create voltage (measure of potential) energy change across the membrane. This electrical charge across the membrane is the membrane poten ...
Nerve Impulses and Action Potential
... Nerve Impulses •Depolarization •A stimulus depolarizes the neuron’s membrane •The membrane is now permeable to sodium as sodium channels open •A depolarized membrane allows sodium (Na+) to flow inside the membrane ...
... Nerve Impulses •Depolarization •A stimulus depolarizes the neuron’s membrane •The membrane is now permeable to sodium as sodium channels open •A depolarized membrane allows sodium (Na+) to flow inside the membrane ...
Phases
... The positive feedback of the rising phase slows At the peak of the action potential, the sodium permeability is maximized and the membrane voltage Vm is nearly equal to the sodium equilibrium voltage ENa. However, the same raised voltage that opened the sodium channels initially also slowly shuts th ...
... The positive feedback of the rising phase slows At the peak of the action potential, the sodium permeability is maximized and the membrane voltage Vm is nearly equal to the sodium equilibrium voltage ENa. However, the same raised voltage that opened the sodium channels initially also slowly shuts th ...
Neural Tissue – Chapter 12
... The stimulus that initiates an action potential is a depolarization large enough to open voltage-regulated sodium channels. That opening occurs at a transmembrane potential known as the threshold. The threshold for a typical axon is between -60mV and -55 mV. If the stimulus does not shift the re ...
... The stimulus that initiates an action potential is a depolarization large enough to open voltage-regulated sodium channels. That opening occurs at a transmembrane potential known as the threshold. The threshold for a typical axon is between -60mV and -55 mV. If the stimulus does not shift the re ...
Neurons - Jordan High School
... Na+ & K+ channels Passive channels always open Chemically gated channels need specific chemicals Voltage-gated channels respond to changes in transmembrane potential ...
... Na+ & K+ channels Passive channels always open Chemically gated channels need specific chemicals Voltage-gated channels respond to changes in transmembrane potential ...
File
... chemical force is into the cell because it has a higher concentration outside the cell and diffuses down its concentration gradient. b. In which direction is the electrical force for sodium? Why? The electrical force is also into the cell because due to the negative charge on the interior of the cel ...
... chemical force is into the cell because it has a higher concentration outside the cell and diffuses down its concentration gradient. b. In which direction is the electrical force for sodium? Why? The electrical force is also into the cell because due to the negative charge on the interior of the cel ...
Neurons, Neurons, Neurons!
... Information from one neuron flows to another neuron across a synapse. The synapse is a small gap separating neurons. The synapse consists of: 1. a presynaptic ending that contains neurotransmitters, mitochondria and other cell organelles, 2. a postsynaptic ending that contains receptor sites for ne ...
... Information from one neuron flows to another neuron across a synapse. The synapse is a small gap separating neurons. The synapse consists of: 1. a presynaptic ending that contains neurotransmitters, mitochondria and other cell organelles, 2. a postsynaptic ending that contains receptor sites for ne ...
here - York University
... Pair-Pulsed ratio: When an action potential fires, it elevates the calcium in the axon terminal. If a second action potential occurs before the calcium is able to return to its steady-state, more calcium will enter causing an elevation in concentration greater than the previous action potential. As ...
... Pair-Pulsed ratio: When an action potential fires, it elevates the calcium in the axon terminal. If a second action potential occurs before the calcium is able to return to its steady-state, more calcium will enter causing an elevation in concentration greater than the previous action potential. As ...
Action_ Resting_Potential
... The binding of a neurotransmitter to an excitatory receptor site results in a positive change in voltage, called an excitatory postsynaptic potential or excitatory PSP. This increases the chances that an action potential will be generated in the postsynaptic cell. ...
... The binding of a neurotransmitter to an excitatory receptor site results in a positive change in voltage, called an excitatory postsynaptic potential or excitatory PSP. This increases the chances that an action potential will be generated in the postsynaptic cell. ...
Invertebrate nervous systems:
... Briefly, the modifications were these:1.The hindbrain became divided into a ventral portion, called the medulla oblongata, a dorsal portion, the cerebellum, and the anterior pons. The medulla became specialized as a control center for some autonomic and somatic pathways concerned with vital function ...
... Briefly, the modifications were these:1.The hindbrain became divided into a ventral portion, called the medulla oblongata, a dorsal portion, the cerebellum, and the anterior pons. The medulla became specialized as a control center for some autonomic and somatic pathways concerned with vital function ...
Nervous Systems
... The anatomy of a neuron. The mechanisms of impulse transmission in a neuron. The process that leads to release of neurotransmitters, and what happens at the synapse. ...
... The anatomy of a neuron. The mechanisms of impulse transmission in a neuron. The process that leads to release of neurotransmitters, and what happens at the synapse. ...
Physio study guide unit 2
... What are Ionotropic receptors? That is, how do they work? Do we ONLY have ionotropic receptors that allow sodium through the channel? Which example of an ionotropic receptor are you responsible for knowing? What ion does it allow through? What are metabotropic receptors? That is, how do they work? W ...
... What are Ionotropic receptors? That is, how do they work? Do we ONLY have ionotropic receptors that allow sodium through the channel? Which example of an ionotropic receptor are you responsible for knowing? What ion does it allow through? What are metabotropic receptors? That is, how do they work? W ...
slides - Smith Lab
... • Excess cation outside the cell pushes K+ back to the cell (Electrical driving force) • Until K+ concentration inside and outside the cell are in equilibrium (-75mV) • Resting membrane potential (Vr ) settles at K+ equilibrium potential (Ek) • Vr = Ek ...
... • Excess cation outside the cell pushes K+ back to the cell (Electrical driving force) • Until K+ concentration inside and outside the cell are in equilibrium (-75mV) • Resting membrane potential (Vr ) settles at K+ equilibrium potential (Ek) • Vr = Ek ...
presentation source
... The membrane has electrical properties that affect the spread of changes in membrane potential ...
... The membrane has electrical properties that affect the spread of changes in membrane potential ...
Neural transmission
... If ion channels are open; diffusion across concentration and electrostatic gradients will occur ...
... If ion channels are open; diffusion across concentration and electrostatic gradients will occur ...
THE NERVOUS SYSTEM CH 48 AND 49
... C. How information is sent thru the nervous system • all cells have a difference in charge on either side of plasma membrane called a membrane potential • Rest membrane potential: Membrane potential of unstimulated neuron • Change in resting membrane potential results in transmission of nerve impul ...
... C. How information is sent thru the nervous system • all cells have a difference in charge on either side of plasma membrane called a membrane potential • Rest membrane potential: Membrane potential of unstimulated neuron • Change in resting membrane potential results in transmission of nerve impul ...
phys Learning Objectives Chapter 5 [10-31
... membrane potential. The diffusion potential is the potential difference between the inside and the outside of the cell. 2. What is the Nernst Potential for an ion? How is it determined? Nernst potential – the diffusion potential level across a membrane that exactly opposes the net diffusion of a par ...
... membrane potential. The diffusion potential is the potential difference between the inside and the outside of the cell. 2. What is the Nernst Potential for an ion? How is it determined? Nernst potential – the diffusion potential level across a membrane that exactly opposes the net diffusion of a par ...
Neurons, Synapses, the Nervous System
... impulse) is an all-or-none response to depolarization of the nerve cell. A stimulus opens voltage-gated sodium channels and Na+ ions enter the cell, bringing the membrane potential to a positive value. In order to generate an action potential, a certain level of depolarization must be achieved, know ...
... impulse) is an all-or-none response to depolarization of the nerve cell. A stimulus opens voltage-gated sodium channels and Na+ ions enter the cell, bringing the membrane potential to a positive value. In order to generate an action potential, a certain level of depolarization must be achieved, know ...
Chapter 17 Part A
... - potassium channels allow K+ (but no Cl-) to cross selectively permeable membrane - charge separation creates an electrical gradient called a voltage difference - outer surface becomes more positive, inner surface more negative - voltage differences are measured at the inner surface of membrane (ne ...
... - potassium channels allow K+ (but no Cl-) to cross selectively permeable membrane - charge separation creates an electrical gradient called a voltage difference - outer surface becomes more positive, inner surface more negative - voltage differences are measured at the inner surface of membrane (ne ...
Resting potential
The relatively static membrane potential of quiescent cells is called the resting membrane potential (or resting voltage), as opposed to the specific dynamic electrochemical phenomena called action potential and graded membrane potential.Apart from the latter two, which occur in excitable cells (neurons, muscles, and some secretory cells in glands), membrane voltage in the majority of non-excitable cells can also undergo changes in response to environmental or intracellular stimuli. In principle, there is no difference between resting membrane potential and dynamic voltage changes like action potential from a biophysical point of view: all these phenomena are caused by specific changes in membrane permeabilities for potassium, sodium, calcium, and chloride ions, which in turn result from concerted changes in functional activity of various ion channels, ion transporters, and exchangers. Conventionally, resting membrane potential can be defined as a relatively stable, ground value of transmembrane voltage in animal and plant cells.Any voltage is a difference in electric potential between two points—for example, the separation of positive and negative electric charges on opposite sides of a resistive barrier. The typical resting membrane potential of a cell arises from the separation of potassium ions from intracellular, relatively immobile anions across the membrane of the cell. Because the membrane permeability for potassium is much higher than that for other ions (disregarding voltage-gated channels at this stage), and because of the strong chemical gradient for potassium, potassium ions flow from the cytosol into the extracellular space carrying out positive charge, until their movement is balanced by build-up of negative charge on the inner surface of the membrane. Again, because of the high relative permeability for potassium, the resulting membrane potential is almost always close to the potassium reversal potential. But in order for this process to occur, a concentration gradient of potassium ions must first be set up. This work is done by the ion pumps/transporters and/or exchangers and generally is powered by ATP.In the case of the resting membrane potential across an animal cell's plasma membrane, potassium (and sodium) gradients are established by the Na+/K+-ATPase (sodium-potassium pump) which transports 2 potassium ions inside and 3 sodium ions outside at the cost of 1 ATP molecule. In other cases, for example, a membrane potential may be established by acidification of the inside of a membranous compartment (such as the proton pump that generates membrane potential across synaptic vesicle membranes).