Cell Membranes The boundary of the cell, sometimes called the
... The boundary of the cell, sometimes called the plasma membrane, separates internal metabolic events from the external environment and controls the movement of materials into and out of the cell. This membrane is very selective about what it allows to pass through; this characteristic is referred to ...
... The boundary of the cell, sometimes called the plasma membrane, separates internal metabolic events from the external environment and controls the movement of materials into and out of the cell. This membrane is very selective about what it allows to pass through; this characteristic is referred to ...
MS Word Version - Interactive Physiology
... 16. (Page 8.) When does the voltage-sensitive gate open? 17. (Page 8.) What is the function of the time-sensitive inactivation gate? 18. (Page 8.) What happens to the voltage gated sodium channels at the peak of the action potential? 19. (Page 9.) When do the voltage-gated potassium channels open? 2 ...
... 16. (Page 8.) When does the voltage-sensitive gate open? 17. (Page 8.) What is the function of the time-sensitive inactivation gate? 18. (Page 8.) What happens to the voltage gated sodium channels at the peak of the action potential? 19. (Page 9.) When do the voltage-gated potassium channels open? 2 ...
GDI
... 1.Inactive (GDP-bound) prenylated Rab GTPases are bound to GDI, which masks their isoprenyl anchor and thereby keeps the Rab in a soluble cytosolic form. 2.Membrane attachment of Rabs requires the function of a GDF that dissociates the GDI–Rab complex and allows the prenyl anchor to be inserted into ...
... 1.Inactive (GDP-bound) prenylated Rab GTPases are bound to GDI, which masks their isoprenyl anchor and thereby keeps the Rab in a soluble cytosolic form. 2.Membrane attachment of Rabs requires the function of a GDF that dissociates the GDI–Rab complex and allows the prenyl anchor to be inserted into ...
Neuron Structure and Function
... - gap junctions link the cytosol of two cells - provide a passageway for movement of very small molecules and ions between the cells - gap junction channels have a large conductance - NO synaptic delay (current spread from cell to cell is instantaneous) - important in some reflexes - chemical synaps ...
... - gap junctions link the cytosol of two cells - provide a passageway for movement of very small molecules and ions between the cells - gap junction channels have a large conductance - NO synaptic delay (current spread from cell to cell is instantaneous) - important in some reflexes - chemical synaps ...
motor unit
... On repeated stimulation by successive action potentials, the cytosolic concentration of Ca2+ remains high The prolonged availability of Ca2+ in the cytosol permits more of the cross bridges to continue participating in the cycling process for a longer time With an increase in the frequency of action ...
... On repeated stimulation by successive action potentials, the cytosolic concentration of Ca2+ remains high The prolonged availability of Ca2+ in the cytosol permits more of the cross bridges to continue participating in the cycling process for a longer time With an increase in the frequency of action ...
Notes- Nerve Impulses and Junctions
... FACT 1: Lentils represent sodium ions. There are more sodium ions outside the nerve cell than inside, so there are more pintos in the “outside” pan. Lima beans represent potassium ions, pinto beans represent chloride ions, and the wads of construction paper represent proteins. In a real cell, there ...
... FACT 1: Lentils represent sodium ions. There are more sodium ions outside the nerve cell than inside, so there are more pintos in the “outside” pan. Lima beans represent potassium ions, pinto beans represent chloride ions, and the wads of construction paper represent proteins. In a real cell, there ...
Checkpoint Answers
... A. are multipolar and carry impulses toward the CNS. *B. are pseudounipolar and carry impulses toward the CNS. C. are bipolar and carry impulses away from the CNS. D. are multipolar and carry impulses away from the CNS. 4. Schwann cells and oligodendrocytes have similar functions. true 5. Regenerati ...
... A. are multipolar and carry impulses toward the CNS. *B. are pseudounipolar and carry impulses toward the CNS. C. are bipolar and carry impulses away from the CNS. D. are multipolar and carry impulses away from the CNS. 4. Schwann cells and oligodendrocytes have similar functions. true 5. Regenerati ...
Chapter 2 – Action potential - Fun-Mooc
... it mean, exactly? It means that the interior surface of the membrane is increasingly less negative with respect to the exterior one, and even inverts, i. e. becomes more positive than the exterior surface. Then, the membrane repolarizes and returns to its initial values. What causes the two phases? ...
... it mean, exactly? It means that the interior surface of the membrane is increasingly less negative with respect to the exterior one, and even inverts, i. e. becomes more positive than the exterior surface. Then, the membrane repolarizes and returns to its initial values. What causes the two phases? ...
Chapter 12 Notes: Nervous Tissue 2014
... slower when cooled _________________________________________________________ ...
... slower when cooled _________________________________________________________ ...
The Cell Membrane Selectively Permeable Membrane
... material transported across the membrane. The membrane is selectively permeable (or semi‐permeable) meaning that certain molecules can cross the membrane and others cannot. ...
... material transported across the membrane. The membrane is selectively permeable (or semi‐permeable) meaning that certain molecules can cross the membrane and others cannot. ...
Neuron File
... between the axon of one neuron and a dendrite or soma of another. Synaptic signals may be excitatory or inhibitory. If the net excitation received by a neuron over a short period of time is large enough, the neuron generates a brief pulse called an action potential, which originates at the soma and ...
... between the axon of one neuron and a dendrite or soma of another. Synaptic signals may be excitatory or inhibitory. If the net excitation received by a neuron over a short period of time is large enough, the neuron generates a brief pulse called an action potential, which originates at the soma and ...
BI 201 Human Anatomy & Physiology
... What about the effects of Ca2+ ions on the resting potential? When extracellular Ca2+ ions are reduced then they _________ _____ ______ (including gated Na+ channels, which causes them to open). What is the result of Hypocalcemia? ...
... What about the effects of Ca2+ ions on the resting potential? When extracellular Ca2+ ions are reduced then they _________ _____ ______ (including gated Na+ channels, which causes them to open). What is the result of Hypocalcemia? ...
Handout 3 - Engineering Class s
... activated by an increase in intracellular free Ca2+ (and because of voltage-dependence of Ca2+ channels, also exhibits a voltage-dependence indirectly) rapid kinetics; activated with 1-2 msec; total duration of 20-50 msec responsible for repolarization and hyperpolarization of membrane highly sensit ...
... activated by an increase in intracellular free Ca2+ (and because of voltage-dependence of Ca2+ channels, also exhibits a voltage-dependence indirectly) rapid kinetics; activated with 1-2 msec; total duration of 20-50 msec responsible for repolarization and hyperpolarization of membrane highly sensit ...
The Generation of Brain Waves
... such as acetylcholine) are released into the synaptic space and drift to the dendrite of the next cell stimulating that cell membrane to depolarize and pass along the impulse. This depolarization is called an excitatory postsynaptic potential (EPSP). An inhibitory postsynaptic potential (IPSP) resul ...
... such as acetylcholine) are released into the synaptic space and drift to the dendrite of the next cell stimulating that cell membrane to depolarize and pass along the impulse. This depolarization is called an excitatory postsynaptic potential (EPSP). An inhibitory postsynaptic potential (IPSP) resul ...
11-1 FUNCTIONS OF THE NERVOUS SYSTEM 1. Sensory input
... A. Stimulus strength: A weak stimulus produces a small graded potential, whereas a stronger stimulus produces a larger graded potential. B. Stimulus frequency: If stimuli (of the same strength) are applied rapidly, one after the other, the effect of the second stimulus summates, or accumulates, prod ...
... A. Stimulus strength: A weak stimulus produces a small graded potential, whereas a stronger stimulus produces a larger graded potential. B. Stimulus frequency: If stimuli (of the same strength) are applied rapidly, one after the other, the effect of the second stimulus summates, or accumulates, prod ...
ANSWERS TO CHAPTER 8
... skeletal muscle; Autonomic nervous system: involuntary, innervates smooth muscle, cardiac muscle, and glands. 3. Multipolar neurons: several dendrites and one axon, includes motor neurons; bipolar neurons: one dendrite and one axon, found in the eye and nose; unipolar neurons: a single process that ...
... skeletal muscle; Autonomic nervous system: involuntary, innervates smooth muscle, cardiac muscle, and glands. 3. Multipolar neurons: several dendrites and one axon, includes motor neurons; bipolar neurons: one dendrite and one axon, found in the eye and nose; unipolar neurons: a single process that ...
Nervous System Dr. Ali Ebneshahidi © 2016 Ebneshahidi
... 4. Absolute refractory period: cell can not be stimulated during this phase (Na+ - K+ pump restores the electrical condition) [pumps 3 Na+ outside, 2 K+ inside]. © 2016 Ebneshahidi ...
... 4. Absolute refractory period: cell can not be stimulated during this phase (Na+ - K+ pump restores the electrical condition) [pumps 3 Na+ outside, 2 K+ inside]. © 2016 Ebneshahidi ...
Ions in Your Life
... receptors and prevent neurotransmitters from being used. Excitation and extra excitation occurs and neurotransmitter stops being produced by the body itself. Neurotransmitters are blocked from going through reuptake transporters by original neuron. Extra excitation occurs and body stops producing ne ...
... receptors and prevent neurotransmitters from being used. Excitation and extra excitation occurs and neurotransmitter stops being produced by the body itself. Neurotransmitters are blocked from going through reuptake transporters by original neuron. Extra excitation occurs and body stops producing ne ...
AP Biology Study Guide
... 4. Define a resting potential and explain how it is created. 5. Explain how an action potential is produced and the resting membrane potential restored. 6. Explain (a) how an action potential propagates itself along a neuron, (b) why action potentials move in only one direction, and (c) how action p ...
... 4. Define a resting potential and explain how it is created. 5. Explain how an action potential is produced and the resting membrane potential restored. 6. Explain (a) how an action potential propagates itself along a neuron, (b) why action potentials move in only one direction, and (c) how action p ...
BIO201 Crimando Vocab 6 BIO201 Nervous System I Vocabulary
... Cation more concentrated in extracellular fluid (ECF): ____________________ Cation more concentrated in intracellular fluid (ICF): ____________________ Ion channel that opens in response to chemical binding: ____________________ Ion channel that opens in response to local change in membrane voltage: ...
... Cation more concentrated in extracellular fluid (ECF): ____________________ Cation more concentrated in intracellular fluid (ICF): ____________________ Ion channel that opens in response to chemical binding: ____________________ Ion channel that opens in response to local change in membrane voltage: ...
LESSON 2.3 WORKBOOK How fast do our neurons signal?
... This is not a great solution because the energy required to keep the Na+/K+ pump working to repolarize the axon membrane is huge. So axons have come up with another strategy, which is to have the action potential jump along the axon rather than progress down it (think of the action potential pogo-st ...
... This is not a great solution because the energy required to keep the Na+/K+ pump working to repolarize the axon membrane is huge. So axons have come up with another strategy, which is to have the action potential jump along the axon rather than progress down it (think of the action potential pogo-st ...
W7 Lecture
... BUT only Na+ can move. Ion movement: Na+ crosses into Compartment 2; but K+ stays in Compartment 2. ...
... BUT only Na+ can move. Ion movement: Na+ crosses into Compartment 2; but K+ stays in Compartment 2. ...
Neuromuscular junctions
... 1 The presynaptic membrane is depolarized. 2 Ca2+ channels on the presynaptic membrane open. 3 There is an Influx of Ca2+2 ions from the synaptic cleft into the synaptic bulb. 4 Vesicles move towards presynaptic membrane. 5 Vesicles fuse with presynaptic membrane. 6 Neurotransmitter e.g. acetylcholi ...
... 1 The presynaptic membrane is depolarized. 2 Ca2+ channels on the presynaptic membrane open. 3 There is an Influx of Ca2+2 ions from the synaptic cleft into the synaptic bulb. 4 Vesicles move towards presynaptic membrane. 5 Vesicles fuse with presynaptic membrane. 6 Neurotransmitter e.g. acetylcholi ...
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.