Nervous System and Senses - Avon Community School Corporation
... Unmyelinated axons- wave continues uninterrupted; relatively slow Myelinated axons- wave goes through saltatory conduction (jump from one node to the next); very fast ...
... Unmyelinated axons- wave continues uninterrupted; relatively slow Myelinated axons- wave goes through saltatory conduction (jump from one node to the next); very fast ...
Biology 12 - Chapter 17 - Biology12-Lum
... • This means how to make it keep moving down the axon • When an action potential reaches a large enough depolarization it is called a threshold • This will make the next section undergo depolarization. • After a section has done its action potential then there is a short period of time for the sodiu ...
... • This means how to make it keep moving down the axon • When an action potential reaches a large enough depolarization it is called a threshold • This will make the next section undergo depolarization. • After a section has done its action potential then there is a short period of time for the sodiu ...
Action potentials
... • It is that period of action potential during which no new action potential can be initiated even by strong stimulus. Relative Refractory period • It is that period during which second action potential can be produced by very strong stimulus. ...
... • It is that period of action potential during which no new action potential can be initiated even by strong stimulus. Relative Refractory period • It is that period during which second action potential can be produced by very strong stimulus. ...
Chapter 11
... synthesis of neurotransmitter i. anterograde transport - movement of material from cell body to synaptic knobs ii. retrograde transport - movement of material from synapse to cell body 3. myelin sheath - wrap of Scwhann cells (PNS) and oligodendricytes (CNS) around the axon a. increases speed of act ...
... synthesis of neurotransmitter i. anterograde transport - movement of material from cell body to synaptic knobs ii. retrograde transport - movement of material from synapse to cell body 3. myelin sheath - wrap of Scwhann cells (PNS) and oligodendricytes (CNS) around the axon a. increases speed of act ...
Nervous System:
... Ion pumps in the cell membranes of neurons release three positively charged sodium ions, while taking in only two positively charged potassium ions which creates a negative charge inside the cell. The space inside the neuron now has a resting potential, which is a kind of membrane potential, because ...
... Ion pumps in the cell membranes of neurons release three positively charged sodium ions, while taking in only two positively charged potassium ions which creates a negative charge inside the cell. The space inside the neuron now has a resting potential, which is a kind of membrane potential, because ...
Title: Nervous System
... c) the minus sign indicates that the inside is negative relative to the outside d) a cell that exhibits a membrane potential is said to be polarized 4. Action potentials (depolarizing phase, threshold, repolarizing phase) a) is a very rapid change in membrane potential that occurs when a nerve cell ...
... c) the minus sign indicates that the inside is negative relative to the outside d) a cell that exhibits a membrane potential is said to be polarized 4. Action potentials (depolarizing phase, threshold, repolarizing phase) a) is a very rapid change in membrane potential that occurs when a nerve cell ...
1. Cell body - greinerudsd
... 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) • Neurotransmitters are either broken down or recycled • This is where drugs interfere ...
... 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) • Neurotransmitters are either broken down or recycled • This is where drugs interfere ...
暨 南 大 学 考 试 试 卷
... C. They branch among themselves that they form the entire planes of T tubules interlacing among all the separate myofibrils. D. They can transmit action potential to the deep interior of the muscle fiber as well to excite each myofibril. 15) The incorrect statement about summation of skeletal muscle ...
... C. They branch among themselves that they form the entire planes of T tubules interlacing among all the separate myofibrils. D. They can transmit action potential to the deep interior of the muscle fiber as well to excite each myofibril. 15) The incorrect statement about summation of skeletal muscle ...
CHAPTER NINE: THE NERVOUS SYSTEM
... i. An increase in membrane potential ii. Inside of the membrane becomes more negative than the resting potential iii. Reduces the probability of producing a nerve impulse c. Occur when a stimulus causes gated ion channels to open d. Decrease in magnitude with distance as ions flow and diffuse throug ...
... i. An increase in membrane potential ii. Inside of the membrane becomes more negative than the resting potential iii. Reduces the probability of producing a nerve impulse c. Occur when a stimulus causes gated ion channels to open d. Decrease in magnitude with distance as ions flow and diffuse throug ...
file - Athens Academy
... B. partly results from the sodium-potassium exchange pump. C. occurs because the cell membrane remains polarized at rest. D. occurs because there are negatively charged proteins and ions inside the cell. E. has all of these contributing factors. ...
... B. partly results from the sodium-potassium exchange pump. C. occurs because the cell membrane remains polarized at rest. D. occurs because there are negatively charged proteins and ions inside the cell. E. has all of these contributing factors. ...
PPT
... • Motor Neurons: send messages from central nervous system to other areas • Interneurons: neurons that are neither sensory or motor neuron; can also describe CNS neurons whose axons do not leave the structure in which they reside ...
... • Motor Neurons: send messages from central nervous system to other areas • Interneurons: neurons that are neither sensory or motor neuron; can also describe CNS neurons whose axons do not leave the structure in which they reside ...
A2.2.2.SecretSignals - jj-sct
... We have learned that chemical and electrical factors work together to send signals. We know that the brain and spinal cord team up to deal with all the messages that are sent around the body on a minute to minute and often a second to second basis. We also know that all body functions depend on thes ...
... We have learned that chemical and electrical factors work together to send signals. We know that the brain and spinal cord team up to deal with all the messages that are sent around the body on a minute to minute and often a second to second basis. We also know that all body functions depend on thes ...
3.13
... and developed a mathematical model for neuron activity. Their work appeared in a series of papers in 1952. It is an excellent example of how experimental and theoretical research can be combined to gain a thorough understanding of a natural system. In 1963, Hodgkin and Huxley were awarded the Nobel ...
... and developed a mathematical model for neuron activity. Their work appeared in a series of papers in 1952. It is an excellent example of how experimental and theoretical research can be combined to gain a thorough understanding of a natural system. In 1963, Hodgkin and Huxley were awarded the Nobel ...
What is the neuron`s resting potential?
... • Two processes are responsible for the unequal distribution of ions across the membrane of resting neurons: 1. The differential permeability of the membrane to the ions. The membrane is most permeable to K+ and Cl-, and last permeable to negatively charged protein ions. 2. The action of sodium-pot ...
... • Two processes are responsible for the unequal distribution of ions across the membrane of resting neurons: 1. The differential permeability of the membrane to the ions. The membrane is most permeable to K+ and Cl-, and last permeable to negatively charged protein ions. 2. The action of sodium-pot ...
1 MCB3210F NAME EXAM 1A SECTION CELLS, TISSUES
... 3. Explain how nerve conduction is speeded in myelinated vs. non-myelinated nerves. 4 pts Schwann cells make myelin to wrap the nerve Ion channels are localized to the nodes of Ranvier Action potentials generated at the nodes only, so it “jumps” from node to node. This wrapping increases the distan ...
... 3. Explain how nerve conduction is speeded in myelinated vs. non-myelinated nerves. 4 pts Schwann cells make myelin to wrap the nerve Ion channels are localized to the nodes of Ranvier Action potentials generated at the nodes only, so it “jumps” from node to node. This wrapping increases the distan ...
Exam
... 3. Explain how nerve conduction is speeded in myelinated vs. non-myelinated nerves. 4 pts Schwann cells make myelin to wrap the nerve Ion channels are localized to the nodes of Ranvier Action potentials generated at the nodes only, so it “jumps” from node to node. This wrapping increases the distan ...
... 3. Explain how nerve conduction is speeded in myelinated vs. non-myelinated nerves. 4 pts Schwann cells make myelin to wrap the nerve Ion channels are localized to the nodes of Ranvier Action potentials generated at the nodes only, so it “jumps” from node to node. This wrapping increases the distan ...
Nervous System
... move inward; inside of cell becomes positively charged relative to outside (reverse polarization or depolarization) 5. Reverse polarization at original site acts as a stimulus to adjacent region of membrane ...
... move inward; inside of cell becomes positively charged relative to outside (reverse polarization or depolarization) 5. Reverse polarization at original site acts as a stimulus to adjacent region of membrane ...
supporting cells - Daniela Sartori
... • Relative refractory period occurs when VG K+ channels are open, making it harder to depolarize to threshold ...
... • Relative refractory period occurs when VG K+ channels are open, making it harder to depolarize to threshold ...
CASE 3
... concentrations in the expression are slight, and Vm is close to EK (∼ −90 mV). In many neuronal cell bodies or dendrites, PNa is somewhat greater than this when the cell is at rest and Vm is more depolarized (eg, ∼ −65 mV). Permeabilities (P) often are referred to by their electrical equivalents, co ...
... concentrations in the expression are slight, and Vm is close to EK (∼ −90 mV). In many neuronal cell bodies or dendrites, PNa is somewhat greater than this when the cell is at rest and Vm is more depolarized (eg, ∼ −65 mV). Permeabilities (P) often are referred to by their electrical equivalents, co ...
The Neuron - Austin Community College
... -The AP travels along the nerve fiber because the flow of ions that depolarize and repolarize the neuron’s membrane act as stimuli for neighboring patches of membrane along the nerve, this mode of travel is called propagation or conduction. All-or-None phenomenon – action potentials either happen c ...
... -The AP travels along the nerve fiber because the flow of ions that depolarize and repolarize the neuron’s membrane act as stimuli for neighboring patches of membrane along the nerve, this mode of travel is called propagation or conduction. All-or-None phenomenon – action potentials either happen c ...
Module 9: Neuron & Action Potential PowerPoint
... • At rest, the inside of the cell is at -70 microvolts • With inputs to dendrites inside becomes more positive • If resting potential rises above threshold, an action potential starts to travel from cell body down the axon • Figure shows resting axon being approached by an AP ...
... • At rest, the inside of the cell is at -70 microvolts • With inputs to dendrites inside becomes more positive • If resting potential rises above threshold, an action potential starts to travel from cell body down the axon • Figure shows resting axon being approached by an AP ...
PDF Steady State of Living Cells and Donnan Equilibrium
... lead to a change in the membrane potential of ΔV . But it is well known that a living cell maintains a constant membrane potential of ΔV ∼ −60mV . USEFUL QUESTIONS you should know how to answer: 1) Why do the flow of ions So the cell is not in equilibrium do not significantly change the ion con ...
... lead to a change in the membrane potential of ΔV . But it is well known that a living cell maintains a constant membrane potential of ΔV ∼ −60mV . USEFUL QUESTIONS you should know how to answer: 1) Why do the flow of ions So the cell is not in equilibrium do not significantly change the ion con ...
The Neuron
... next neuron. Here they bind to receptors proteins on the surface of the cell - as a key fits into a lock. On delivery of their 'messages' these chemical couriers are destroyed or reabsorbed by the nerve endings in which they were produced. ...
... next neuron. Here they bind to receptors proteins on the surface of the cell - as a key fits into a lock. On delivery of their 'messages' these chemical couriers are destroyed or reabsorbed by the nerve endings in which they were produced. ...
Hodgkin-Huxley model of the action potential in the the squid giant
... where v is the membrane voltage (inside cell minus outside cell) and measured relative to the resting potential of around -60 mV. The units in the above expression are in mV. A comparison of the above equations for opening and closing rates to the original data derived from Hodgkin and Huxley’s expe ...
... where v is the membrane voltage (inside cell minus outside cell) and measured relative to the resting potential of around -60 mV. The units in the above expression are in mV. A comparison of the above equations for opening and closing rates to the original data derived from Hodgkin and Huxley’s expe ...
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.