the nervous sys. The function of neuron & Glia
... sure the ion concentrations recover to their original quantities, a Na/K pump within the membrane moves Na out and K in. Because the pump is moving ions against their concentration gradients requires energy (breakdown of stored ATP. 2. Recall that after Na channels have been activated and open a few ...
... sure the ion concentrations recover to their original quantities, a Na/K pump within the membrane moves Na out and K in. Because the pump is moving ions against their concentration gradients requires energy (breakdown of stored ATP. 2. Recall that after Na channels have been activated and open a few ...
Biology 621 - Chapter 12 Midterm Exam Review
... 24.Sensory neurons carry impulses from receptors to the spinal cord. 25. What are the two major division of the peripheral nervous system? autonomic &somatic 26 Nervous system subdivision that is composed of the brain and spinal cord.CNS 27.The neuron is the basic functional unit of the nervous syst ...
... 24.Sensory neurons carry impulses from receptors to the spinal cord. 25. What are the two major division of the peripheral nervous system? autonomic &somatic 26 Nervous system subdivision that is composed of the brain and spinal cord.CNS 27.The neuron is the basic functional unit of the nervous syst ...
Chapter 11: Membrane transport
... Active transport Cells can use various forms of energy to drive transport against concentration or charge gradients What kind of energy is used? –transport of some molecules fueled by the energy of ATP –membrane potential can drive the transport of charged molecules ...
... Active transport Cells can use various forms of energy to drive transport against concentration or charge gradients What kind of energy is used? –transport of some molecules fueled by the energy of ATP –membrane potential can drive the transport of charged molecules ...
What is the neuron`s resting potential?
... • Two processes maintain the unequal distribution of ions across the membrane of resting neurons: 1. The differential permeability of the membrane to ions (most permeable to K+ and Cl-; least permeable to negatively charged protein ions). 2. The action of sodium-potassium pumps (continually exchang ...
... • Two processes maintain the unequal distribution of ions across the membrane of resting neurons: 1. The differential permeability of the membrane to ions (most permeable to K+ and Cl-; least permeable to negatively charged protein ions). 2. The action of sodium-potassium pumps (continually exchang ...
Lecture Outline
... action potential to be re-initiated there. This process is repeated over and over again as the action potential travels the length of the axon. o At each position along the axon, the process is identical, such that the shape and magnitude of the action potential remain constant. Immediately behind t ...
... action potential to be re-initiated there. This process is repeated over and over again as the action potential travels the length of the axon. o At each position along the axon, the process is identical, such that the shape and magnitude of the action potential remain constant. Immediately behind t ...
12 Steps to Muscle Contraction
... 1. A nerve impulse travels to the neuromuscular junction on a muscle cell. The neuromuscular junction is the point where the axons of the nerve meet with the muscle cell. 2. Ach is released from the axon to receptors located on the sarcolemma 3. The binding Ach causes depolarization of the sarcolemm ...
... 1. A nerve impulse travels to the neuromuscular junction on a muscle cell. The neuromuscular junction is the point where the axons of the nerve meet with the muscle cell. 2. Ach is released from the axon to receptors located on the sarcolemma 3. The binding Ach causes depolarization of the sarcolemm ...
Neurons, Synapses, and Signaling
... o This represents the movement of far fewer ions than would be required to alter the chemical concentration gradient. ...
... o This represents the movement of far fewer ions than would be required to alter the chemical concentration gradient. ...
Membrane Structure & Function
... i = ionization constant (For sucrose this is 1.0 because sucrose does not ionize in water.) ...
... i = ionization constant (For sucrose this is 1.0 because sucrose does not ionize in water.) ...
peripheral nervous system
... Nerve Impulse Transmission Each action potential, in its rising phase, reflects a reversal in membrane polarity -Positive charges due to influx of Na+ can depolarize the adjacent region to threshold -And so the next region produces its own action potential -Meanwhile, the previous region repolarize ...
... Nerve Impulse Transmission Each action potential, in its rising phase, reflects a reversal in membrane polarity -Positive charges due to influx of Na+ can depolarize the adjacent region to threshold -And so the next region produces its own action potential -Meanwhile, the previous region repolarize ...
What is the neuron`s resting potential?
... • Two processes maintain the unequal distribution of ions across the membrane of resting neurons: 1. The differential permeability of the membrane to ions (most permeable to K+ and Cl-; least permeable to negatively charged protein ions). 2. The action of sodium-potassium pumps (continually exchang ...
... • Two processes maintain the unequal distribution of ions across the membrane of resting neurons: 1. The differential permeability of the membrane to ions (most permeable to K+ and Cl-; least permeable to negatively charged protein ions). 2. The action of sodium-potassium pumps (continually exchang ...
Biology 12 Name: Nervous System Practice Exam Types of Neurons
... 19. If potassium ions could not diffuse out of the axon, which of the following would result? a) Repolarization would not occur. b) A neurotransmitter would be released. c) The length of the recovery phase would be reduced. d) The frequency of action potentials would be increased. 20. Why can an imp ...
... 19. If potassium ions could not diffuse out of the axon, which of the following would result? a) Repolarization would not occur. b) A neurotransmitter would be released. c) The length of the recovery phase would be reduced. d) The frequency of action potentials would be increased. 20. Why can an imp ...
Notes of Neuronal Firing
... A graded potential can only travel a short distance because the change in voltage spreads by the passive movement of ions in a process called electrotonic conduction. As the current moves further from the site of stimulation, the membrane potential decreases because the ions diffuse and the ions pas ...
... A graded potential can only travel a short distance because the change in voltage spreads by the passive movement of ions in a process called electrotonic conduction. As the current moves further from the site of stimulation, the membrane potential decreases because the ions diffuse and the ions pas ...
Chapter 13: The Nervous System
... There are two different types of cells found in the nervous system, these are ___________________ and ___________________. Glial cells are often called neuroglial cells, they are ______________________________________ cells. So what are they important for? ...
... There are two different types of cells found in the nervous system, these are ___________________ and ___________________. Glial cells are often called neuroglial cells, they are ______________________________________ cells. So what are they important for? ...
22 reflexes 1 - The reflex arc
... If these excitatory potentials summate enough to bring the efferent membrane to threshold, the efferent neuron fires The efferent axon also carries all-or-none action potentials The neuromuscular junction the response there is also the need for summation, but the excitatory post-synaptic potential i ...
... If these excitatory potentials summate enough to bring the efferent membrane to threshold, the efferent neuron fires The efferent axon also carries all-or-none action potentials The neuromuscular junction the response there is also the need for summation, but the excitatory post-synaptic potential i ...
Biochemical screen for potential membrane fission catalysts
... Eukaryotic cells are functionally compartmentalized in form of an elaborate endomembrane system comprising of intracellular organelles such as the endoplasmic reticulum, Golgi apparatus, endosomes and lysosome. Membrane budding and fission results in the generation of transport carriers that sort an ...
... Eukaryotic cells are functionally compartmentalized in form of an elaborate endomembrane system comprising of intracellular organelles such as the endoplasmic reticulum, Golgi apparatus, endosomes and lysosome. Membrane budding and fission results in the generation of transport carriers that sort an ...
chapter38
... to a stimulus. A stimulus has to be of enough strength to cause an action potential to occur. The critical point at which a stimulus causes an action potential is called the threshold. ...
... to a stimulus. A stimulus has to be of enough strength to cause an action potential to occur. The critical point at which a stimulus causes an action potential is called the threshold. ...
Introduction to Skeletal Muscle
... • peripheral proteins (plasma membrane receptors) – associated with surface of bilayer – e.g., adenylate cyclase, kinases, hormone receptors ...
... • peripheral proteins (plasma membrane receptors) – associated with surface of bilayer – e.g., adenylate cyclase, kinases, hormone receptors ...
lecture #6
... • Saltatory conduction -depolarization only at nodes of Ranvier - areas along the axon that are unmyelinated and where there is a high density of voltage-gated ion channels -current carried by ions flows through extracellular fluid from node to node ...
... • Saltatory conduction -depolarization only at nodes of Ranvier - areas along the axon that are unmyelinated and where there is a high density of voltage-gated ion channels -current carried by ions flows through extracellular fluid from node to node ...
Learning Objectives
... 6. Define a membrane potential and a resting potential. 7. Describe the factors that contribute to a membrane potential. 8. Explain the role of the sodium-potassium pump in maintaining the resting potential. 9. Distinguish between gated and ungated ion channels and among ligand-gated ion channels an ...
... 6. Define a membrane potential and a resting potential. 7. Describe the factors that contribute to a membrane potential. 8. Explain the role of the sodium-potassium pump in maintaining the resting potential. 9. Distinguish between gated and ungated ion channels and among ligand-gated ion channels an ...
action potential
... The importance of the plateau is that it can account for the prolonged contraction that occurs in some types of smooth muscle, such as the ureter, the uterus under some conditions, and certain types of vascular smooth muscle . ...
... The importance of the plateau is that it can account for the prolonged contraction that occurs in some types of smooth muscle, such as the ureter, the uterus under some conditions, and certain types of vascular smooth muscle . ...
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.