ch 48 nervous system
... • Postsynaptic potentials fall into two categories – Excitatory postsynaptic potentials (EPSPs) are depolarizations that bring the membrane potential toward threshold – Inhibitory postsynaptic potentials (IPSPs) are hyperpolarizations that move the membrane potential farther from threshold ...
... • Postsynaptic potentials fall into two categories – Excitatory postsynaptic potentials (EPSPs) are depolarizations that bring the membrane potential toward threshold – Inhibitory postsynaptic potentials (IPSPs) are hyperpolarizations that move the membrane potential farther from threshold ...
Nervous System Notes
... knob, causing release of calcium ions to diffuse into the knob Increased calcium concentrations trigger the release of neurotransmitters via exocytosis Neurotransmitters diffuse across the synaptic cleft and bind to receptor molecules causing ion channels to open This causes postsynaptic poten ...
... knob, causing release of calcium ions to diffuse into the knob Increased calcium concentrations trigger the release of neurotransmitters via exocytosis Neurotransmitters diffuse across the synaptic cleft and bind to receptor molecules causing ion channels to open This causes postsynaptic poten ...
Neurophysiology – Action Potential, Nerve Impulse, and Synapses
... glutamic acid, aspartic acid, and gamma-aminobutyric acid (GABA) and a large group of neuropeptides which are short chains of amino acids. Acetylcholine and norepinephrine are excitatory. Dopamine, GABA, and gIycine are inhibitory. Neurotransmitters are synthesized in the cytoplasm of the cell body ...
... glutamic acid, aspartic acid, and gamma-aminobutyric acid (GABA) and a large group of neuropeptides which are short chains of amino acids. Acetylcholine and norepinephrine are excitatory. Dopamine, GABA, and gIycine are inhibitory. Neurotransmitters are synthesized in the cytoplasm of the cell body ...
BIOLOGY II: CHAPTER 9: Neuromuscular Junction
... 3. Sodium ions, Na+ ,diffuse from their higher concentration (in the synaptic cleft) to their lower concentration (inside the muscle cell). Potassium ions, K+, diffuse from their higher concentration (inside the muscle cell) to their lower concentration (in the synaptic cleft). 4. Depolarization of ...
... 3. Sodium ions, Na+ ,diffuse from their higher concentration (in the synaptic cleft) to their lower concentration (inside the muscle cell). Potassium ions, K+, diffuse from their higher concentration (inside the muscle cell) to their lower concentration (in the synaptic cleft). 4. Depolarization of ...
Unit IV-D Outline
... second, traveling in jumps from one node of Ranvier to another (salutatory conduction), depolarization occurring only at the nodes utilizing less active transport; faster and uses less energy i. threshold – the minimum level of sensitivity of a nerve cell which must be exceeded by the strength of th ...
... second, traveling in jumps from one node of Ranvier to another (salutatory conduction), depolarization occurring only at the nodes utilizing less active transport; faster and uses less energy i. threshold – the minimum level of sensitivity of a nerve cell which must be exceeded by the strength of th ...
2 slides/page - University of San Diego Home Pages
... • chips of cells (pinched off cytoplasm from marrow cells) • function: clotting; fibrinogen a plasma protein seals leaks in vessels; multiple clotting factors ...
... • chips of cells (pinched off cytoplasm from marrow cells) • function: clotting; fibrinogen a plasma protein seals leaks in vessels; multiple clotting factors ...
File
... direction, it will elicit an action potential in the postsynaptic neuron, thus exciting it. (In this case, the EPSP is +20 millivolts—that is, 20 millivolts more positive than the resting value.) However, we must issue a word of warning. Discharge of a single presynaptic terminal can never increase ...
... direction, it will elicit an action potential in the postsynaptic neuron, thus exciting it. (In this case, the EPSP is +20 millivolts—that is, 20 millivolts more positive than the resting value.) However, we must issue a word of warning. Discharge of a single presynaptic terminal can never increase ...
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Nervous Tissue
... If the duration of the absolute refractory period of a nerve cell is 1millisecond (ms), this many action potentials are generated by a maximal stimulus in 1 second: a. 1 b. 10 c. 100 d. 1000 ...
... If the duration of the absolute refractory period of a nerve cell is 1millisecond (ms), this many action potentials are generated by a maximal stimulus in 1 second: a. 1 b. 10 c. 100 d. 1000 ...
Final Exam - Creighton Biology
... u. Propagation would be faster due to better insulation along the entire axon. v. Propagation would be faster due to less time taken up generating new action potentials at the nodes. w. Propagation would be slower due to less ion exchange between the cell and interstitial fluid. x. Propagation would ...
... u. Propagation would be faster due to better insulation along the entire axon. v. Propagation would be faster due to less time taken up generating new action potentials at the nodes. w. Propagation would be slower due to less ion exchange between the cell and interstitial fluid. x. Propagation would ...
（一）Functional Anatomy of the Retina
... The membrane of the receptor region is, however, electrically inexcitable; it contains no voltage-gated ionic channels and does not generate spikes. If the receptor region generated action potentials, the graded nature of the generator potential would be destroyed because as soon as the generator p ...
... The membrane of the receptor region is, however, electrically inexcitable; it contains no voltage-gated ionic channels and does not generate spikes. If the receptor region generated action potentials, the graded nature of the generator potential would be destroyed because as soon as the generator p ...
REVIEW THE NERVOUS SYSTEM
... 43. What are the spaces between adjacent neurons called? 44. A change in the environment that may be of sufficient strength to initiate an impulse is called a(an) 45. The minimum level of a stimulus that is required to activate a neuron is called the 46. The long fiber that carries impulses away fro ...
... 43. What are the spaces between adjacent neurons called? 44. A change in the environment that may be of sufficient strength to initiate an impulse is called a(an) 45. The minimum level of a stimulus that is required to activate a neuron is called the 46. The long fiber that carries impulses away fro ...
Chapter 3: The Biological Bases of Behavior
... • Glia – structural support and insulation • Neurons – communication – Soma – cell body – Dendrites – receive – Axon – transmit away – Myelin sheath – speeds up transmission – Terminal Button – end of axon; secretes neurotransmitters – Neurotransmitters – chemical messengers ...
... • Glia – structural support and insulation • Neurons – communication – Soma – cell body – Dendrites – receive – Axon – transmit away – Myelin sheath – speeds up transmission – Terminal Button – end of axon; secretes neurotransmitters – Neurotransmitters – chemical messengers ...
Eagleman Ch 3. Neurons and Synapses
... outside world are encoded by different neurons. Population coding is the idea that each stimulus is represented by a collection of neurons. ...
... outside world are encoded by different neurons. Population coding is the idea that each stimulus is represented by a collection of neurons. ...
Neuroscience 7a – Neuromuscular, spinal cord
... The contact ratio (i.e. the number of neurones that are in contact with others) can range from 1:1 to 1: 1000. Central synapses allow for multiple inputs to a single cell. They have 2 types of transmission at the post-synaptic terminal: - EPSP: Excitatory Post-Synaptic Potentials - IPSP: Inhibitory ...
... The contact ratio (i.e. the number of neurones that are in contact with others) can range from 1:1 to 1: 1000. Central synapses allow for multiple inputs to a single cell. They have 2 types of transmission at the post-synaptic terminal: - EPSP: Excitatory Post-Synaptic Potentials - IPSP: Inhibitory ...
Synaptic transmission
... • In addition, some postsynaptic neurons respond with large numbers of output impulses, and others respond with only a few. Thus, the synapses perform a selective action, often blocking weak signals while allowing strong signals to pass, but at other times selecting and amplifying certain weak signa ...
... • In addition, some postsynaptic neurons respond with large numbers of output impulses, and others respond with only a few. Thus, the synapses perform a selective action, often blocking weak signals while allowing strong signals to pass, but at other times selecting and amplifying certain weak signa ...
lesson 6
... membrane results in the inside of the neuron being 70 mV less positive than the outside ...
... membrane results in the inside of the neuron being 70 mV less positive than the outside ...
The Nervous System
... for ions such as Na+, K+, and Cl-. Depending on which gates open the postsynaptic neuron can depolarize or hyperpolarize. ...
... for ions such as Na+, K+, and Cl-. Depending on which gates open the postsynaptic neuron can depolarize or hyperpolarize. ...
Chapter 49 The Neuromuscular Junction and Muscle Contraction
... Three conformations of the Ach receptor ...
... Three conformations of the Ach receptor ...
WP - edl.io
... axon ( see fig. 10.16). However, at the nodes of Ranvier, between the Schwann cells, the myelin is absent. At these nodes there are sodium and potassium channels that allow for action potentials. The action potentials appear to jump from node to node ( really the entire myelin covered Schwann cell i ...
... axon ( see fig. 10.16). However, at the nodes of Ranvier, between the Schwann cells, the myelin is absent. At these nodes there are sodium and potassium channels that allow for action potentials. The action potentials appear to jump from node to node ( really the entire myelin covered Schwann cell i ...
- Google Sites
... impulses to the opposite side of the body. Most people exhibit hemisphere dominance for the language-related activities of speech, writing, and reading. Which hemisphere is dominant in 90% of the population? What does the non-dominant hemisphere specialize in? What are the main functions of the basa ...
... impulses to the opposite side of the body. Most people exhibit hemisphere dominance for the language-related activities of speech, writing, and reading. Which hemisphere is dominant in 90% of the population? What does the non-dominant hemisphere specialize in? What are the main functions of the basa ...
Membrane structure, I
... Become limp or flaccid when lose turgor pressure Plasmolysis - plasma membrane pulls away from cell wall ...
... Become limp or flaccid when lose turgor pressure Plasmolysis - plasma membrane pulls away from cell wall ...
Neurobiology 360: Electrical and Chemical Synapses 1a) What is
... means there must be a gate allowing information to flow in one direction while preventing it from flowing in the other. 2) Compare and contrast electrical synaptic transmission with chemical synaptic transmission. Electrical synapses in general connect two cells together via the cytoplasm (i.e. they ...
... means there must be a gate allowing information to flow in one direction while preventing it from flowing in the other. 2) Compare and contrast electrical synaptic transmission with chemical synaptic transmission. Electrical synapses in general connect two cells together via the cytoplasm (i.e. they ...
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.