11-1 FUNCTIONS OF THE NERVOUS SYSTEM 1. Sensory input
... B. Voltage-gated ion channels open and close in response to small voltage changes across the plasma membrane. The small voltages are measured in units called millivolts. A millivolt (mV) is 1/1000 of a volt. This type of ion channel is important in the production of action potentials. C. Other gate ...
... B. Voltage-gated ion channels open and close in response to small voltage changes across the plasma membrane. The small voltages are measured in units called millivolts. A millivolt (mV) is 1/1000 of a volt. This type of ion channel is important in the production of action potentials. C. Other gate ...
CHAP 17c - Dr. Gerry Cronin
... section 117 of the 1976 United States Copyright Act without express permission of the copyright owner is unlawful. Request for further information should be addressed to the Permission Department, John Wiley & Sons, Inc. The purchaser may make back-up copies for his/her own use only and not for dist ...
... section 117 of the 1976 United States Copyright Act without express permission of the copyright owner is unlawful. Request for further information should be addressed to the Permission Department, John Wiley & Sons, Inc. The purchaser may make back-up copies for his/her own use only and not for dist ...
Composition of the Nervous System
... -The structure of a typical neuronal cell is comprised of a body, many branching dendrites and a single branching axon. The proximal part of the axon is called the axon hillock. -Schematic neurons: Particularly when drawing circuits neurons can represented in a schematic way by a circle (cell body a ...
... -The structure of a typical neuronal cell is comprised of a body, many branching dendrites and a single branching axon. The proximal part of the axon is called the axon hillock. -Schematic neurons: Particularly when drawing circuits neurons can represented in a schematic way by a circle (cell body a ...
to get the file
... outside, while negative ions (A-) and plenty of K+ are more concentrated inside. ...
... outside, while negative ions (A-) and plenty of K+ are more concentrated inside. ...
conductance versus current-based integrate-and - Neuro
... However, an additional mode is also present in which a balanced increase in the excitatory and inhibitory drives can in some cases cause a decrease in the membrane potential fluctuations - again due to the competing conductance increase. This is reminiscent of the decrease in firing rate with increa ...
... However, an additional mode is also present in which a balanced increase in the excitatory and inhibitory drives can in some cases cause a decrease in the membrane potential fluctuations - again due to the competing conductance increase. This is reminiscent of the decrease in firing rate with increa ...
Synapses - UBC Zoology
... - provide a passageway for movement of very small molecules and ions between the cells - gap junction channels have a large conductance - NO synaptic delay (current spread from cell to cell is instantaneous) - important in some reflexes - chemical synapses do have a significant delay ie slow - commo ...
... - provide a passageway for movement of very small molecules and ions between the cells - gap junction channels have a large conductance - NO synaptic delay (current spread from cell to cell is instantaneous) - important in some reflexes - chemical synapses do have a significant delay ie slow - commo ...
File
... Axon: Long single extension of a neuron, covered with myelin [MY-uh-lin] sheath to insulate and speed up messages through neurons. Terminal Branches of axon: Branched endings of an axon that transmit messages to other neurons. ...
... Axon: Long single extension of a neuron, covered with myelin [MY-uh-lin] sheath to insulate and speed up messages through neurons. Terminal Branches of axon: Branched endings of an axon that transmit messages to other neurons. ...
action potential — epilepsy
... will form the peak of the action potential, the membrane potential has become positive (inside vs. outside) due to the entry of sodium ions. Unlike the situation described for the resting membrane, both the diffusional force (potassium is concentrated inside the nerve cell) and electrical force (pot ...
... will form the peak of the action potential, the membrane potential has become positive (inside vs. outside) due to the entry of sodium ions. Unlike the situation described for the resting membrane, both the diffusional force (potassium is concentrated inside the nerve cell) and electrical force (pot ...
The Nervous System
... • Resting state - when neuron is not stimulated • But, not truly resting – still working to maintain resting state • Sodium-Potassium Pump – proteins in the neuron’s cell membrane pump sodium ions out and potassium ions into the cell • Sodium can’t diffuse through membrane on its own which creates a ...
... • Resting state - when neuron is not stimulated • But, not truly resting – still working to maintain resting state • Sodium-Potassium Pump – proteins in the neuron’s cell membrane pump sodium ions out and potassium ions into the cell • Sodium can’t diffuse through membrane on its own which creates a ...
Na + - Tufts
... • When a neuron receives signals from another neuron it may reach threshold. • If threshold is reached, Na+ channels open. ...
... • When a neuron receives signals from another neuron it may reach threshold. • If threshold is reached, Na+ channels open. ...
The Nervous System - Catherine Huff`s Site
... • Resting state - when neuron is not stimulated • But, not truly resting – still working to maintain resting state • Sodium-Potassium Pump – proteins in the neuron’s cell membrane pump sodium ions out and potassium ions into the cell • Sodium can’t diffuse through membrane on its own which creates a ...
... • Resting state - when neuron is not stimulated • But, not truly resting – still working to maintain resting state • Sodium-Potassium Pump – proteins in the neuron’s cell membrane pump sodium ions out and potassium ions into the cell • Sodium can’t diffuse through membrane on its own which creates a ...
File
... • The equilibrium potential is the diffusion potential that exactly balances (opposes) the tendency for diffusion caused by a concentration difference. At electrochemical equilibrium, the chemical and electrical driving forces that act on an ion are equal and opposite, and no more net diffusion of t ...
... • The equilibrium potential is the diffusion potential that exactly balances (opposes) the tendency for diffusion caused by a concentration difference. At electrochemical equilibrium, the chemical and electrical driving forces that act on an ion are equal and opposite, and no more net diffusion of t ...
Biology 12 Name: Nervous System Practice Exam Types of Neurons
... c) The length of the recovery phase would be reduced. d) The frequency of action potentials would be increased. 20. Why can an impulse traveling along an axon not reverse its direction? a) The myelin sheath will only permit one-way travel of an impulse. b) Sodium gates remain closed until the impuls ...
... c) The length of the recovery phase would be reduced. d) The frequency of action potentials would be increased. 20. Why can an impulse traveling along an axon not reverse its direction? a) The myelin sheath will only permit one-way travel of an impulse. b) Sodium gates remain closed until the impuls ...
File
... • The movement of an action potential down a neuron is caused by the moving exchange of sodium (Na+) and potassium (K+) ions moving in and out of the cell. • The movement of an action potential through a neuron consists of 2 main stages : depolarization and repolarization. ...
... • The movement of an action potential down a neuron is caused by the moving exchange of sodium (Na+) and potassium (K+) ions moving in and out of the cell. • The movement of an action potential through a neuron consists of 2 main stages : depolarization and repolarization. ...
Introduction to electrophysiological recordings
... bilayer of phospholipids that preserve differences between the intra and extracellular environments, and thus preventing the freely diffusion of molecules. ...
... bilayer of phospholipids that preserve differences between the intra and extracellular environments, and thus preventing the freely diffusion of molecules. ...
The Nervous System
... integrated through inter-actions between postsynaptic potentials ((the inter-actions are the simplest level of information processing)). ...
... integrated through inter-actions between postsynaptic potentials ((the inter-actions are the simplest level of information processing)). ...
Final Exam - Creighton Biology
... Which of the following must normally be present for the generation of a membrane potential to occur? p. q. r. s. t. ...
... Which of the following must normally be present for the generation of a membrane potential to occur? p. q. r. s. t. ...
Neural Control II
... • There are two basic types of synapses: – Electrical synapses – involve direct cytoplasmic connections between the two cells formed by gap junctions; the gap junctions allow ion currents to continue; relatively rare in vertebrates – Chemical synapses – electrical impulses must be converted to a che ...
... • There are two basic types of synapses: – Electrical synapses – involve direct cytoplasmic connections between the two cells formed by gap junctions; the gap junctions allow ion currents to continue; relatively rare in vertebrates – Chemical synapses – electrical impulses must be converted to a che ...
Notes0112
... - an organic molecule that donates the necessary eletrons to form coordinate covalent bonds with metallic ions, as oxygen is bound to the central atom of Hb. This term is also used to indicate any ion or molecule that reacts to form a complex with another molecule, frequently a macromolecule. Ion ch ...
... - an organic molecule that donates the necessary eletrons to form coordinate covalent bonds with metallic ions, as oxygen is bound to the central atom of Hb. This term is also used to indicate any ion or molecule that reacts to form a complex with another molecule, frequently a macromolecule. Ion ch ...
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).