Paper I
... 4. If the two structures are both on the left side of the body, they are If one is on the left and the other is on the right, they are ...
... 4. If the two structures are both on the left side of the body, they are If one is on the left and the other is on the right, they are ...
01.22.10 Lecture 5: Membrane transport
... Ion channels have ion selectivity - they only allow passage of specific molecules ...
... Ion channels have ion selectivity - they only allow passage of specific molecules ...
Bioelectric Signal Recording
... An Action Potential is a rapid alteration of the transmembrane voltage generated by the activity of voltage-gated ion channels embedded in the cell membranes. It can be divided into five phases: the resting potential (1), threshold, the rising phase (2), the falling phase (3) and the recovery phase ...
... An Action Potential is a rapid alteration of the transmembrane voltage generated by the activity of voltage-gated ion channels embedded in the cell membranes. It can be divided into five phases: the resting potential (1), threshold, the rising phase (2), the falling phase (3) and the recovery phase ...
Structure of a Neuron Transmission of “Information” Nerve Impulse
... – Difference approx 70 mV, expressed as –70mV ...
... – Difference approx 70 mV, expressed as –70mV ...
Electrochemical Impulses
... • The wave of depolarization is followed by a wave of re-polarization • The action potential moves along the axon by jumping from one node of Ranvier to another ...
... • The wave of depolarization is followed by a wave of re-polarization • The action potential moves along the axon by jumping from one node of Ranvier to another ...
Resting Potential
... A. Synapses are often very localized on a neuron. They open channels that allow current to flow into the cell. If, for example, the channels that open are permeable to sodium, sodium ions will enter and depolarize the cell as the membrane potential moves toward the sodium equilibrium potential. ...
... A. Synapses are often very localized on a neuron. They open channels that allow current to flow into the cell. If, for example, the channels that open are permeable to sodium, sodium ions will enter and depolarize the cell as the membrane potential moves toward the sodium equilibrium potential. ...
Lectures220Week7Note..
... 3. In this way, electrical signals continue to jump down the axon much faster than they can move down an unmyelinated cell. ...
... 3. In this way, electrical signals continue to jump down the axon much faster than they can move down an unmyelinated cell. ...
Nervous System Cells
... • Many vertebrate peripheral neurons have an insulating sheath around the axon called myelin which is formed by Schwann cells. • Myelin sheathing allows these neurons to conduct nerve impulses faster than in non-myelinated neurons. ...
... • Many vertebrate peripheral neurons have an insulating sheath around the axon called myelin which is formed by Schwann cells. • Myelin sheathing allows these neurons to conduct nerve impulses faster than in non-myelinated neurons. ...
CENTENNIAL HONORS COLLEGE Western Illinois University Undergraduate Research Day 2015
... Undergraduate Research Day 2015 Poster Presentation Characterizing an Abnormal Action Potential Pattern in Ion-Channel-Mutant Drosophila Mariah Maiman Faculty Mentor: Jeffrey Engel Biology Repetitive activities such as flight are organized by neural networks called central pattern generators and the ...
... Undergraduate Research Day 2015 Poster Presentation Characterizing an Abnormal Action Potential Pattern in Ion-Channel-Mutant Drosophila Mariah Maiman Faculty Mentor: Jeffrey Engel Biology Repetitive activities such as flight are organized by neural networks called central pattern generators and the ...
Neurology - wsscience
... Chemical synapses differ from electric synapses because chemical synapses: Contain integral proteins Involve a neurotransmitter Involve direct physical contact between cells Propagate action potentials quickly and efficiently ...
... Chemical synapses differ from electric synapses because chemical synapses: Contain integral proteins Involve a neurotransmitter Involve direct physical contact between cells Propagate action potentials quickly and efficiently ...
PHYSIOLOGY OF THE NERVOUS SYSTEM
... • Caused by a shift in membrane potentials along the axon! • Detection of STIMULUS ...
... • Caused by a shift in membrane potentials along the axon! • Detection of STIMULUS ...
Document
... What is an electrical gradient, how does the gradient lead to polarization and a resting potential, and how does the membrane of the cell work to maintain this gradient? How does one measure the resting potential and electrical activity inside neurons? How does the flow of sodium, potassium, chlorid ...
... What is an electrical gradient, how does the gradient lead to polarization and a resting potential, and how does the membrane of the cell work to maintain this gradient? How does one measure the resting potential and electrical activity inside neurons? How does the flow of sodium, potassium, chlorid ...
Membrane Potential
... • “An action potential achieved at one region of the membrane is sufficient to depolarize a neighboring region above threshold” • Triggers a new action potential • Refractory period assures that impulse conduction is unidirectional ...
... • “An action potential achieved at one region of the membrane is sufficient to depolarize a neighboring region above threshold” • Triggers a new action potential • Refractory period assures that impulse conduction is unidirectional ...
Types of neurons - Brigham Young University
... You photoreceptors can detect down to 1 photon -70 mV across 3nm is equivalent to 200,000V across 1cm ...
... You photoreceptors can detect down to 1 photon -70 mV across 3nm is equivalent to 200,000V across 1cm ...
How neurons communicate ACTION POTENTIALS
... from cell body • They are created when a stimulus causes a depolarizing current • The resting potential moves toward 0mV • When it reaches a level of -55 mV, it will “fire” an action potential ...
... from cell body • They are created when a stimulus causes a depolarizing current • The resting potential moves toward 0mV • When it reaches a level of -55 mV, it will “fire” an action potential ...
48 Nervous System PowerPoint
... >Speed of Transmission: Larger axons & Myelin sheath (Saltatory conduction) ...
... >Speed of Transmission: Larger axons & Myelin sheath (Saltatory conduction) ...
Nerve Impulse Transmission
... Inside the cell: becomes negative again => restoring the resting potential at -70mV (but ions are in reverse positions) ...
... Inside the cell: becomes negative again => restoring the resting potential at -70mV (but ions are in reverse positions) ...
Fundamental Types of Neurons
... mechanisms for producing electrical potentials & currents – electrical potential - difference in concentration of charged particles between different parts of the cell – electrical current - flow of charged particles from one point to another within the cell • Living cells are polarized – resting me ...
... mechanisms for producing electrical potentials & currents – electrical potential - difference in concentration of charged particles between different parts of the cell – electrical current - flow of charged particles from one point to another within the cell • Living cells are polarized – resting me ...
Introduction to Anatomy
... basic properties of their cell membranes: 1. There is an electrical voltage, called the resting membrane potential, across the cell membrane. 2. Their cell membranes contain a variety of ion channels (pores) that may be open or ...
... basic properties of their cell membranes: 1. There is an electrical voltage, called the resting membrane potential, across the cell membrane. 2. Their cell membranes contain a variety of ion channels (pores) that may be open or ...
Exam 1 suggested answers (2010)
... 2.a. A synapse with Erev more negative than threshold is inhibitory. Even though it results in a depolarization when the neuron is at resting potential, this makes it harder for the neuron to depolarize to levels less negative than the E rev, thus making it harder to reach threshold. b. In this situ ...
... 2.a. A synapse with Erev more negative than threshold is inhibitory. Even though it results in a depolarization when the neuron is at resting potential, this makes it harder for the neuron to depolarize to levels less negative than the E rev, thus making it harder to reach threshold. b. In this situ ...
NEUROPHYSIOLOGY
... Every millisecond, more + charges leave the cell by diffusion than enter it. So the outside gains a slight + charge and the inside a negative charge The voltage gated Na+ and K+ channels are closed ...
... Every millisecond, more + charges leave the cell by diffusion than enter it. So the outside gains a slight + charge and the inside a negative charge The voltage gated Na+ and K+ channels are closed ...
General design of the nervous system
... , where Pr is permeability of the ion, and the sum is over ...
... , where Pr is permeability of the ion, and the sum is over ...
chapter 8 neuronal physiology B
... strength of the stimulating event • Depolarization wave known as local current flow • Strength depends on how much charge enters the cell • Decreases in strength as it travels through the cytoplasm • Can be depolarizing or hyperpolarizing ...
... strength of the stimulating event • Depolarization wave known as local current flow • Strength depends on how much charge enters the cell • Decreases in strength as it travels through the cytoplasm • Can be depolarizing or hyperpolarizing ...
Nervous System
... • What factors help maintain this negative resting potential? • Neurons have ionic channels in the membrane that allows the membrane potential to change • How is the resting potential maintained in a neuron if there are ionic channels that allow for diffusion of ions? ...
... • What factors help maintain this negative resting potential? • Neurons have ionic channels in the membrane that allows the membrane potential to change • How is the resting potential maintained in a neuron if there are ionic channels that allow for diffusion of ions? ...
Action potential
In physiology, an action potential is a short-lasting event in which the electrical membrane potential of a cell rapidly rises and falls, following a consistent trajectory. Action potentials occur in several types of animal cells, called excitable cells, which include neurons, muscle cells, and endocrine cells, as well as in some plant cells. In neurons, they play a central role in cell-to-cell communication. In other types of cells, their main function is to activate intracellular processes. In muscle cells, for example, an action potential is the first step in the chain of events leading to contraction. In beta cells of the pancreas, they provoke release of insulin. Action potentials in neurons are also known as ""nerve impulses"" or ""spikes"", and the temporal sequence of action potentials generated by a neuron is called its ""spike train"". A neuron that emits an action potential is often said to ""fire"".Action potentials are generated by special types of voltage-gated ion channels embedded in a cell's plasma membrane. These channels are shut when the membrane potential is near the resting potential of the cell, but they rapidly begin to open if the membrane potential increases to a precisely defined threshold value. When the channels open (in response to depolarization in transmembrane voltage), they allow an inward flow of sodium ions, which changes the electrochemical gradient, which in turn produces a further rise in the membrane potential. This then causes more channels to open, producing a greater electric current across the cell membrane, and so on. The process proceeds explosively until all of the available ion channels are open, resulting in a large upswing in the membrane potential. The rapid influx of sodium ions causes the polarity of the plasma membrane to reverse, and the ion channels then rapidly inactivate. As the sodium channels close, sodium ions can no longer enter the neuron, and then they are actively transported back out of the plasma membrane. Potassium channels are then activated, and there is an outward current of potassium ions, returning the electrochemical gradient to the resting state. After an action potential has occurred, there is a transient negative shift, called the afterhyperpolarization or refractory period, due to additional potassium currents. This mechanism prevents an action potential from traveling back the way it just came.In animal cells, there are two primary types of action potentials. One type is generated by voltage-gated sodium channels, the other by voltage-gated calcium channels. Sodium-based action potentials usually last for under one millisecond, whereas calcium-based action potentials may last for 100 milliseconds or longer. In some types of neurons, slow calcium spikes provide the driving force for a long burst of rapidly emitted sodium spikes. In cardiac muscle cells, on the other hand, an initial fast sodium spike provides a ""primer"" to provoke the rapid onset of a calcium spike, which then produces muscle contraction.