53 XIX BLY 122 Lecture Notes (O`Brien)
... Principles of Electrical Signaling (45.1) A. The anatomy of a neuron 1. Neurons consist of a cell body, dendrites, and one or more axons. Fig 45.3a 2. Neurons transmit information via electrical impulses. Fig 45.1a a. Sensory receptors transmit information about the internal or external environment ...
... Principles of Electrical Signaling (45.1) A. The anatomy of a neuron 1. Neurons consist of a cell body, dendrites, and one or more axons. Fig 45.3a 2. Neurons transmit information via electrical impulses. Fig 45.1a a. Sensory receptors transmit information about the internal or external environment ...
File
... Any stimulus that can increase the voltage of cytoplasm to -55 mV or more causes an action potential. When the threshold level is reached at -55 mV, the voltage of the cytoplasm suddenly reaches 0 and overshoots to +35 mV. In fact, the membrane is depolarized. ...
... Any stimulus that can increase the voltage of cytoplasm to -55 mV or more causes an action potential. When the threshold level is reached at -55 mV, the voltage of the cytoplasm suddenly reaches 0 and overshoots to +35 mV. In fact, the membrane is depolarized. ...
File - Biology with Radjewski
... • Measure of the difference in electrical charge between 2 points • Represents potential energy because opposite charges will move together if given a chance • In wires, electrical current is carried by electrons • In solutions and across cell membranes, electric current is carried by ions ...
... • Measure of the difference in electrical charge between 2 points • Represents potential energy because opposite charges will move together if given a chance • In wires, electrical current is carried by electrons • In solutions and across cell membranes, electric current is carried by ions ...
a positive electrical signal
... receives electrical signals and releases chemical signals out of the neuron ...
... receives electrical signals and releases chemical signals out of the neuron ...
Ch 48 Notes - FacStaff Home Page for CBU
... while the concentration of Na is highest outside the cell ...
... while the concentration of Na is highest outside the cell ...
Madison Pejsa Pd.4
... to coordinate voluntary movements, posture, and balance in humans, being in back of and below the cerebrum and consisting of two lateral lobes and a central lobe. ...
... to coordinate voluntary movements, posture, and balance in humans, being in back of and below the cerebrum and consisting of two lateral lobes and a central lobe. ...
HONORS BIOLOGY Chapter 28 Nervous Systems
... Resting potential—voltage across the plasma membrane The resting potential exists because of differences in ion concentration inside and outside a cell ...
... Resting potential—voltage across the plasma membrane The resting potential exists because of differences in ion concentration inside and outside a cell ...
6.2 Transmission of Nerve Impulses
... 1. A neuron at rest has more sodium ions (Na+) outside the membrane than potassium (K+) ions inside, therefore there is a more negative charge inside the neuron - The neuron is said to be polarized 2. If stimulus is received it must reach a critical voltage before it will have an effect on the neuro ...
... 1. A neuron at rest has more sodium ions (Na+) outside the membrane than potassium (K+) ions inside, therefore there is a more negative charge inside the neuron - The neuron is said to be polarized 2. If stimulus is received it must reach a critical voltage before it will have an effect on the neuro ...
How Neurons and Synapses Work
... local potential aka graded potential If its big enough it causes action potential ...
... local potential aka graded potential If its big enough it causes action potential ...
Membrane Transport
... – Overall not limited by size, charge, or hydrophilia – Is highly selective for specific needed molecules – Rate is fast and not linear ...
... – Overall not limited by size, charge, or hydrophilia – Is highly selective for specific needed molecules – Rate is fast and not linear ...
Action Potentials are - Winona State University
... When excitable cells (neurons and myofibers) are at rest they have lots of potassium on the inside and lots of sodium outside of the cell. They exhibit excitability when Na+ and/or K+ suddenly move across the plasma membrane through special channels that open for this specific purpose! These channe ...
... When excitable cells (neurons and myofibers) are at rest they have lots of potassium on the inside and lots of sodium outside of the cell. They exhibit excitability when Na+ and/or K+ suddenly move across the plasma membrane through special channels that open for this specific purpose! These channe ...
AP – All or nothing
... membrane, this is repolarisation • The membrane briefly becomes hyperpolarised (more negative on the inside than usual) • The Na+ / K+ channels close ...
... membrane, this is repolarisation • The membrane briefly becomes hyperpolarised (more negative on the inside than usual) • The Na+ / K+ channels close ...
chapter 48
... o Allows only ONE kind of ion to pass through o Any resulting net movement of positive or negative charge generates a _____________________ ______________________ or ___________________________ across the membrane. o In other words: the action of the ion channels serves to “defeat” the action of the ...
... o Allows only ONE kind of ion to pass through o Any resulting net movement of positive or negative charge generates a _____________________ ______________________ or ___________________________ across the membrane. o In other words: the action of the ion channels serves to “defeat” the action of the ...
Slideshow
... maintain a voltage difference across the cell membrane called a resting membrane potential. The inside of the cell is more negatively charged in comparison to the outside of the cell – this is shown by a negative sign in front of voltage, (ex., - 70 mV) The big players here are sodium and potassium ...
... maintain a voltage difference across the cell membrane called a resting membrane potential. The inside of the cell is more negatively charged in comparison to the outside of the cell – this is shown by a negative sign in front of voltage, (ex., - 70 mV) The big players here are sodium and potassium ...
Packet 6- The neuron
... A signal is transmitted when a STIMULUS triggers a neuron…and causes an ACTION POTENTIAL (aka nerve impulse). The action potential was discovered in 1952 by Huxley and Hodgkin after studying giant squid axons. General description of an ACTION POTENTIAL: 1. Stimulus triggers the opening of “STIMULUS ...
... A signal is transmitted when a STIMULUS triggers a neuron…and causes an ACTION POTENTIAL (aka nerve impulse). The action potential was discovered in 1952 by Huxley and Hodgkin after studying giant squid axons. General description of an ACTION POTENTIAL: 1. Stimulus triggers the opening of “STIMULUS ...
Transport across cell membranes
... Everything else requires a transport protein If the substance already wants to be inside (eg. its moving down a concentration gradient) energy is not required and you might call this FACILITATED DIFFUSION – eg. glucose transport When you move against the gradient (electrical or chemical) energy in t ...
... Everything else requires a transport protein If the substance already wants to be inside (eg. its moving down a concentration gradient) energy is not required and you might call this FACILITATED DIFFUSION – eg. glucose transport When you move against the gradient (electrical or chemical) energy in t ...
The Neuron - Austin Community College
... Diffusion – movement of ions through semipermeable membrane Ions flow along their chemical gradient when they move from an area of high concentration to an area of low concentration Together, the electrical and chemical gradients constitute the electrochemical gradient Review: Passive and Active Tra ...
... Diffusion – movement of ions through semipermeable membrane Ions flow along their chemical gradient when they move from an area of high concentration to an area of low concentration Together, the electrical and chemical gradients constitute the electrochemical gradient Review: Passive and Active Tra ...
48 Nervous System PowerPoint
... Outside is always zero Less (+) inside = “-” inside and “+” outside ...
... Outside is always zero Less (+) inside = “-” inside and “+” outside ...
Nervous System
... • Interneurons – neurons that integrate sensory input with motor output • Interneuron branches can carry signals to different parts of spinal cord or brain – Convergent circuits bring information from different ...
... • Interneurons – neurons that integrate sensory input with motor output • Interneuron branches can carry signals to different parts of spinal cord or brain – Convergent circuits bring information from different ...
Nervous System PowerPoint
... After the impulse, the gates return to the resting condition with extra potassium gates open. The flow of potassium ions out of the cell restores the resting potential. The Na+/K+ pump continues to pump the sodium and potassium across the membrane against the concentration gradient to restore th ...
... After the impulse, the gates return to the resting condition with extra potassium gates open. The flow of potassium ions out of the cell restores the resting potential. The Na+/K+ pump continues to pump the sodium and potassium across the membrane against the concentration gradient to restore th ...
Fundamental Types of Neurons
... – 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 membrane potential is -70 mV with a relatively negative char ...
... – 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 membrane potential is -70 mV with a relatively negative char ...
5-2_NeurotransmRelease_BenseM
... membrane of postsynaptic target, structure and modify the electric and metabolic conditions of the affected cells. Main stages of neurotransmitter release: 1. When the action potential comes down the axon and reaches the axon terminal, the membrane potential will change 2. This change will open volt ...
... membrane of postsynaptic target, structure and modify the electric and metabolic conditions of the affected cells. Main stages of neurotransmitter release: 1. When the action potential comes down the axon and reaches the axon terminal, the membrane potential will change 2. This change will open volt ...
Lect5
... Ion currents underlying the AP 1. The Na+ current activates quickly and then inactivates quickly 2. The K+ current activates more slowly and persists longer ...
... Ion currents underlying the AP 1. The Na+ current activates quickly and then inactivates quickly 2. The K+ current activates more slowly and persists longer ...
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).