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! ...
Chapter 12
... of energy. It contains mitochondria, golgi app., ribosomes, and RER. The gray clusters of RER and free ribosomes are called Nissl bodies. ...
... of energy. It contains mitochondria, golgi app., ribosomes, and RER. The gray clusters of RER and free ribosomes are called Nissl bodies. ...
The Nervous System
... 1. A nerve impulse begins with a stimulus- usually this is a neurotransmitter released by other neurons, pain receptors, light excites receptors in the eye, etc. 2. Once the neuron is stimulated the “sodium gates” of the neuron open and sodium ions begin flowing across the cell membrane. This is cal ...
... 1. A nerve impulse begins with a stimulus- usually this is a neurotransmitter released by other neurons, pain receptors, light excites receptors in the eye, etc. 2. Once the neuron is stimulated the “sodium gates” of the neuron open and sodium ions begin flowing across the cell membrane. This is cal ...
General principle of nervous system
... • Opening of postsynaptic channels for a very short period ...
... • Opening of postsynaptic channels for a very short period ...
Ch. 10 Outline
... B. A nerve impulse is conducted whenever a stimulus of threshold intensity or above is applied to an axon C. All impulses carried on an axon are the same strength Refractory Period A. Absolute Refractory Period 1. Time when threshold stimulus does not start another action potential B. Relative Refra ...
... B. A nerve impulse is conducted whenever a stimulus of threshold intensity or above is applied to an axon C. All impulses carried on an axon are the same strength Refractory Period A. Absolute Refractory Period 1. Time when threshold stimulus does not start another action potential B. Relative Refra ...
pttx
... membrane. In this way, local currents of ions across the plasma membrane cause the action potential to be propagated along the length of the axon. ...
... membrane. In this way, local currents of ions across the plasma membrane cause the action potential to be propagated along the length of the axon. ...
Chapter 35-2
... A stimulus must have enough strength to cause a neuron to start an impulse The minimum level of a stimulus that is required to activate a neuron is called the THRESHOLD ...
... A stimulus must have enough strength to cause a neuron to start an impulse The minimum level of a stimulus that is required to activate a neuron is called the THRESHOLD ...
Dopamine axons of substantia nigra pars compacta neurons and
... with PD are widely distributed in the nervous system and affect many classes of neurons, dopamine (DA) neurons of the substantia nigra pars compacta (SNc) show exceptional and selective vulnerability. One factor that distinguishes SNc DA neurons from other DA neurons is their massive axonal arbour a ...
... with PD are widely distributed in the nervous system and affect many classes of neurons, dopamine (DA) neurons of the substantia nigra pars compacta (SNc) show exceptional and selective vulnerability. One factor that distinguishes SNc DA neurons from other DA neurons is their massive axonal arbour a ...
Jan 7, 2015. PASSIVE ELECTRICAL PROPERTIES OF MEMBRANES
... From example trace given in class; Measure time constant Measure change in membrane potential resulting from a given injection of current Calculate input resistance Calculate total capacitance of cell membrane Estimate diameter of the cell ...
... From example trace given in class; Measure time constant Measure change in membrane potential resulting from a given injection of current Calculate input resistance Calculate total capacitance of cell membrane Estimate diameter of the cell ...
Membrane Transport
... • The leak channel lets more + ions out • The electrical potential rises until it equals & balances the K+ concentration gradient = no more leak ...
... • The leak channel lets more + ions out • The electrical potential rises until it equals & balances the K+ concentration gradient = no more leak ...
The Nervous System - Riverside Preparatory High School
... Neuron Function 1. Irritability: ability to respond to stimulus & convert to nerve impulse 2. Conductivity: transmit impulse to other neurons, muscles, or glands ...
... Neuron Function 1. Irritability: ability to respond to stimulus & convert to nerve impulse 2. Conductivity: transmit impulse to other neurons, muscles, or glands ...
The Neuron: Building Block of the Nervous System
... The Action Potential All-or-None Principle – Refers to the fact that the ...
... The Action Potential All-or-None Principle – Refers to the fact that the ...
Chapter 10
... A myelinated nerve fiber is one, which is bound by Schwann cells longitudinally along its length. The Schwann cells wrap tightly around the nerve fiber and form a myelin sheath. Unmyelinated nerve fibers lack these sheaths. In this case, these Schwann cells are not wound around the axons but simply ...
... A myelinated nerve fiber is one, which is bound by Schwann cells longitudinally along its length. The Schwann cells wrap tightly around the nerve fiber and form a myelin sheath. Unmyelinated nerve fibers lack these sheaths. In this case, these Schwann cells are not wound around the axons but simply ...
CHAPTER 5 SIGNALLING IN NEURONS
... cell membrane. Binding of the neurotransmitter molecule to the receptor causes the associated ion channel to open, letting ions pass through. 5.1.2. Neurotransmitters and graded potentials. There are many different molecules that can act as neurotransmitters. When small amounts of neurotransmitter ...
... cell membrane. Binding of the neurotransmitter molecule to the receptor causes the associated ion channel to open, letting ions pass through. 5.1.2. Neurotransmitters and graded potentials. There are many different molecules that can act as neurotransmitters. When small amounts of neurotransmitter ...
ch 48 clicker questions
... a) most Cl− channels closed. b) most Na+ channels opened. c) most K+ channels closed. d) most K+ channels opened. e) Na/K pumps were inactivated. ...
... a) most Cl− channels closed. b) most Na+ channels opened. c) most K+ channels closed. d) most K+ channels opened. e) Na/K pumps were inactivated. ...
Specialized Tissue in Animals
... • Synapse – the point where the axon from one neuron meets the dendrites of another neuron; the point through which a signal can be passed • Action potentials – the electrical signals that transmit information across neurons away from a cell body • Resting potential – the negative intracellular char ...
... • Synapse – the point where the axon from one neuron meets the dendrites of another neuron; the point through which a signal can be passed • Action potentials – the electrical signals that transmit information across neurons away from a cell body • Resting potential – the negative intracellular char ...
The Nervous System
... How does gray matter different from white matter (other than color)? Is it possible for a neuron to regenerate? If so, explain how. How does the cell membrane of a neuron become polarized? What are the major ions associated with with generating a membrane potential? Explain what a threshold potentia ...
... How does gray matter different from white matter (other than color)? Is it possible for a neuron to regenerate? If so, explain how. How does the cell membrane of a neuron become polarized? What are the major ions associated with with generating a membrane potential? Explain what a threshold potentia ...
1 Anatomy 36 VAG Packet Unit 3 How are hormones transported in
... Cells maintain concentration gradients. What is the gradient that is established and maintained for the following ions: ...
... Cells maintain concentration gradients. What is the gradient that is established and maintained for the following ions: ...
The Nervous System
... – Major internal ion is K+, major external ion is Na+ – As long as internal environment is relatively negative, neuron will stay inactive ...
... – Major internal ion is K+, major external ion is Na+ – As long as internal environment is relatively negative, neuron will stay inactive ...
File
... Presynaptic neuron- sends signal Postsynaptic neuron- receives signal How does this happen? The arrival of an action potential at an axon’s terminal triggers the release of NEUROTRANSMITTERS- chemicals that transmit information from one neuron to another Collected together in little sacks ...
... Presynaptic neuron- sends signal Postsynaptic neuron- receives signal How does this happen? The arrival of an action potential at an axon’s terminal triggers the release of NEUROTRANSMITTERS- chemicals that transmit information from one neuron to another Collected together in little sacks ...
Lecture Outline ()
... 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 ...
... 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 ...
View document as PDF
... The boundaries of a cell are determined by the presence of a lipid bilayer known as the cell membrane. This nonpolar structural feature enables the cell to have specific characteristics within the intracellular compartment relative to its extracellular environment. In order to maintain a constant en ...
... The boundaries of a cell are determined by the presence of a lipid bilayer known as the cell membrane. This nonpolar structural feature enables the cell to have specific characteristics within the intracellular compartment relative to its extracellular environment. In order to maintain a constant en ...
Chapter 33
... basilar membrane to vibrate up and down causing its hair cells to bend. The bending of the hair cells depolarizes their membranes sending action potentials that travel via the auditory nerve to the brain. ...
... basilar membrane to vibrate up and down causing its hair cells to bend. The bending of the hair cells depolarizes their membranes sending action potentials that travel via the auditory nerve to the brain. ...
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.