Lecture #19 - Suraj @ LUMS
... membrane carrier proteins. 2. Some Na + rushes in = depolarization. Inside of cell becomes locally + instead of –. 3. Local ion channels close, no more Na + ions enter. 4. Active transport then pumps Na + back out. This is called repolarization. Cell regains "-" charge inside, "+" charge outside. 5. ...
... membrane carrier proteins. 2. Some Na + rushes in = depolarization. Inside of cell becomes locally + instead of –. 3. Local ion channels close, no more Na + ions enter. 4. Active transport then pumps Na + back out. This is called repolarization. Cell regains "-" charge inside, "+" charge outside. 5. ...
Nervous system 12-13
... wave of opening ion channels moves down neuron signal moves in one direction flow of K+ out of cell stops activation of Na+ channels in wrong direction ...
... wave of opening ion channels moves down neuron signal moves in one direction flow of K+ out of cell stops activation of Na+ channels in wrong direction ...
MEMBRANE PERMEABILITY ! membranes are highly impermeable
... solutes flow rapidly by diffusion ! always move from high c to low c (down gradient) ! transport rate # substrate concentration, not saturable ! ΔG !ve, spontaneous, no energy required ! animal cells have many ion channels; highly selective, only let specific ions pass through ! channels open and cl ...
... solutes flow rapidly by diffusion ! always move from high c to low c (down gradient) ! transport rate # substrate concentration, not saturable ! ΔG !ve, spontaneous, no energy required ! animal cells have many ion channels; highly selective, only let specific ions pass through ! channels open and cl ...
Document
... __B__9. What is the function of neurotransmitters? a. builds new neurons b. chemically link neurons across the synapse to conduct impulses c. push sodium ions across the plasma membrane d. increases the speed of the impulse along the axon __B__10. The minimum level of a stimulus that is required to ...
... __B__9. What is the function of neurotransmitters? a. builds new neurons b. chemically link neurons across the synapse to conduct impulses c. push sodium ions across the plasma membrane d. increases the speed of the impulse along the axon __B__10. The minimum level of a stimulus that is required to ...
Mind, Brain & Behavior
... All parts of the cell are made up of protein molecules of different kinds. ...
... All parts of the cell are made up of protein molecules of different kinds. ...
Notes: Nerve Transmission (1)
... Okay … so what do we know? … * The membrane is an insulator (it doesn’t really conduct well). But, the cell membrane is embedded with specialized molecules (proteins) that will pump out ions, or let ions flow in. We know that ions, in water can indeed conduct an electrical current. We know that the ...
... Okay … so what do we know? … * The membrane is an insulator (it doesn’t really conduct well). But, the cell membrane is embedded with specialized molecules (proteins) that will pump out ions, or let ions flow in. We know that ions, in water can indeed conduct an electrical current. We know that the ...
Exam #2 Review Answers - Iowa State University
... d. Presynaptic neuron e. Myelin sheath 20. The sodium-potassium pump: a. Pumps 3 Na+ ions out of the cell and 2 K+ ions into the cell b. Pumps 3 Na+ ions into the cell and 2 K+ ions out of the cell c. Pumps 2 Na+ ions out of the cell and 3 K+ ions into the cell d. Pumps 2 Na+ ions into the cell and ...
... d. Presynaptic neuron e. Myelin sheath 20. The sodium-potassium pump: a. Pumps 3 Na+ ions out of the cell and 2 K+ ions into the cell b. Pumps 3 Na+ ions into the cell and 2 K+ ions out of the cell c. Pumps 2 Na+ ions out of the cell and 3 K+ ions into the cell d. Pumps 2 Na+ ions into the cell and ...
Nervous System
... One extension is different from all the others, and is called the axon. The purpose of the axon is to transmit an electro-chemical signal to other neurons, sometimes over a considerable distance. In the neurons that make up the nerves running from the spinal cord to your toes, the axons can be as lo ...
... One extension is different from all the others, and is called the axon. The purpose of the axon is to transmit an electro-chemical signal to other neurons, sometimes over a considerable distance. In the neurons that make up the nerves running from the spinal cord to your toes, the axons can be as lo ...
AP Biology Animal Form and Function
... another kind of gated channel opens, this time allowing the K+ on the inside to rush out of the cell. The movement of K+ out of the cell causes repolarization by restoring the original membrane polarization (a condition where it is once again more negative inside the cell) Unlike the resting potenti ...
... another kind of gated channel opens, this time allowing the K+ on the inside to rush out of the cell. The movement of K+ out of the cell causes repolarization by restoring the original membrane polarization (a condition where it is once again more negative inside the cell) Unlike the resting potenti ...
Anat3_01_Nervous_Tissue
... there are very few sodium leakage channels. Sodium ions do slowly diffuse into the cell, which would eventually destroy the resting membrane potential. Na+/K+ ATPases pump sodium back out of the cell and bring potassium back in. They pump out 3 Na+ for every 2 K+ they bring in. ...
... there are very few sodium leakage channels. Sodium ions do slowly diffuse into the cell, which would eventually destroy the resting membrane potential. Na+/K+ ATPases pump sodium back out of the cell and bring potassium back in. They pump out 3 Na+ for every 2 K+ they bring in. ...
nervous system
... muscle contraction. An impulse is triggered at one end of a nerve by the binding of neurotransmitters to the ...
... muscle contraction. An impulse is triggered at one end of a nerve by the binding of neurotransmitters to the ...
Ch 48-49 Reading Guide
... 7. Explain how the Nernst equation may be used to calculate EK, the equilibrium potential for K+. 48.3 Action Potentials 8. Describe the characteristics of an action potential. Explain the role of voltage-gated ion channels in this process. 9. Define the refractory period. 10. Explain why the action ...
... 7. Explain how the Nernst equation may be used to calculate EK, the equilibrium potential for K+. 48.3 Action Potentials 8. Describe the characteristics of an action potential. Explain the role of voltage-gated ion channels in this process. 9. Define the refractory period. 10. Explain why the action ...
The Nervous System * Crash Course Biology
... channels. When an action potential begins ______ channels open and ______ rushes in making it less negative inside. With enough stimulus it reaches a threshold and more _______ channels respond and open and let ____ ions in. This happens in one tiny area of the neuron but the change in voltage creep ...
... channels. When an action potential begins ______ channels open and ______ rushes in making it less negative inside. With enough stimulus it reaches a threshold and more _______ channels respond and open and let ____ ions in. This happens in one tiny area of the neuron but the change in voltage creep ...
Sodium Potassium Pump and Nerve Impulse
... These effects seem to be mediated via phosphorylation or dephosphorylation of the pumps. Insulin is a major regulator of potassium homeostasis and has multiple effects on sodium pump activity. Within minutes of elevated insulin secretion, pumps have increased affinity for sodium and increased turnov ...
... These effects seem to be mediated via phosphorylation or dephosphorylation of the pumps. Insulin is a major regulator of potassium homeostasis and has multiple effects on sodium pump activity. Within minutes of elevated insulin secretion, pumps have increased affinity for sodium and increased turnov ...
Document
... – Also decreases the synthesis of neurosteroid hormones (e.g. DHEA, progesterone) which may regulate emotional state – Acts on areas of the limbic system, the thalamus and the ...
... – Also decreases the synthesis of neurosteroid hormones (e.g. DHEA, progesterone) which may regulate emotional state – Acts on areas of the limbic system, the thalamus and the ...
Lidocaine: a Common Local Anaesthetic How does it work and how
... of administration to the brain. They are designed not to distribute widely in the body. They are easily broken down (chemically) by the body's defence mechanisms that exist to allow excretion of xenobiotics (foreign molecules). This means that the duration of action is limited and so feeling returns ...
... of administration to the brain. They are designed not to distribute widely in the body. They are easily broken down (chemically) by the body's defence mechanisms that exist to allow excretion of xenobiotics (foreign molecules). This means that the duration of action is limited and so feeling returns ...
A3 - Viktor`s Notes for the Neurosurgery Resident
... although subthreshold stimuli do not produce action potential, they do have effect on membrane potential (ELECTROTONIC POTENTIALS): – stimulating CATHODE leads to localized depolarizing potential change that rises sharply and decays exponentially with time (catelectrotonic potential); – stimulatin ...
... although subthreshold stimuli do not produce action potential, they do have effect on membrane potential (ELECTROTONIC POTENTIALS): – stimulating CATHODE leads to localized depolarizing potential change that rises sharply and decays exponentially with time (catelectrotonic potential); – stimulatin ...
CHAPTER 4 How do neurons transmit information?
... Resting Potential: Voltage across the cell membrane produced by a greater negative charge on the intracellular side in the absence of stimulation (-70 mV). • Concentration gradient • Voltage gradient • Permeability of membrane ...
... Resting Potential: Voltage across the cell membrane produced by a greater negative charge on the intracellular side in the absence of stimulation (-70 mV). • Concentration gradient • Voltage gradient • Permeability of membrane ...
Recording Techniques Goal of Electrophysiological Recording
... Impossible (?) to record from multiple locations on the same cell ...
... Impossible (?) to record from multiple locations on the same cell ...
1. Cell body
... into the synaptic cleft (via exocytosis) – Neurotransmitters diffuse across gap & bind to receptors on the adjacent neuron – Cause the impulse to continue (if threshold is reached) http://www.hhmi.org/biointeractive/molecular-mechanism-synaptic-function ...
... into the synaptic cleft (via exocytosis) – Neurotransmitters diffuse across gap & bind to receptors on the adjacent neuron – Cause the impulse to continue (if threshold is reached) http://www.hhmi.org/biointeractive/molecular-mechanism-synaptic-function ...
Chapter 11: Fundamentals of the Nervous System and Nervous Tissue
... 4. Propagation of Action Potentials (Fig 12.21) Each action potential acts as a stimulus for development of another action potential in an adjacent segment of membrane The Na+ inflow during the depolarization phase of an action potential diffuses to an adjacent membrane segment Increase in Na+ conce ...
... 4. Propagation of Action Potentials (Fig 12.21) Each action potential acts as a stimulus for development of another action potential in an adjacent segment of membrane The Na+ inflow during the depolarization phase of an action potential diffuses to an adjacent membrane segment Increase in Na+ conce ...
Chapter 12 - Mesa Community College
... 4. Propagation of Action Potentials (Fig 12.21) Each action potential acts as a stimulus for development of another action potential in an adjacent segment of membrane The Na+ inflow during the depolarization phase of an action potential diffuses to an adjacent membrane segment Increase in Na+ conce ...
... 4. Propagation of Action Potentials (Fig 12.21) Each action potential acts as a stimulus for development of another action potential in an adjacent segment of membrane The Na+ inflow during the depolarization phase of an action potential diffuses to an adjacent membrane segment Increase in Na+ conce ...
Slide ()
... Anatomy of the cochlea. A low magnification light micrograph of a near midmodiolar cross-section illustrates the tissues and fluid-filled spaces of the 2½ turns of the mouse cochlea. As indicated in the upper turn, the fluid spaces are the scala tympani and scala vestibuli filled with perilymph, and ...
... Anatomy of the cochlea. A low magnification light micrograph of a near midmodiolar cross-section illustrates the tissues and fluid-filled spaces of the 2½ turns of the mouse cochlea. As indicated in the upper turn, the fluid spaces are the scala tympani and scala vestibuli filled with perilymph, and ...
Nerves Part 1 Powerpoint
... PNS neurons in clusters called ganglia (sing. ganglion) – Only the axons stick out into the rest of the body – The axon of the neuron can be regrown if the soma is intact! ...
... PNS neurons in clusters called ganglia (sing. ganglion) – Only the axons stick out into the rest of the body – The axon of the neuron can be regrown if the soma is intact! ...
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.