The term central nervous system refers to the ________. The neural impulse is the electrical charge that goes from the B) A nerve impulse occurs if the excitatory and inhibitory effects are equal. If the temperature is higher, the rate of diffusion of sodium and potassium ions will be high and axon will become depolarized quickly which will cause a faster nerve impulse conduction. a single depolarization. This area is called the synaptic cleft. Opening K+ or Cl- channels in a postsynaptic There is space between the pre-synaptic neuron and post-synaptic neuron which is known as synaptic cleft or synaptic gap. What generally determines the effects of a neurotransmitter on a postsynaptic cell? 38. For every two potassium ions that move inside the cell, three sodium ions are transported outside. They are generated when the nerve Which of the following will occur when an excitatory postsynaptic Which of the following would be the most typical urinary output in a day? Following the entrance of Ca2+ is the release of neurotransmitter. Anatomy Test #3d Flashcards Advertisement Advertisement Once an action potential has been generated at the axon hillock, it is conducted along the length of the axon until it reaches the terminals, the fingerlike extensions of the neuron that are next to other neurons and muscle cells (see the section The nerve cell: The neuron). Which of the following is not a function of the autonomic nervous system? zoneD) Secretory regionE) Trigger zone. In contrast to electrical transmission, which takes place with almost no delay, chemical transmission exhibits synaptic delay. When the voltage has the required number of electron particles it conducts current. This reverse polarity constitutes the nerve impulse. The part of the neuron that normally receives stimuli is called ________. d) generator potential, Which of the following describes the excitatory postsynaptic potential? The inside of the membrane becomes negative again. C) found in ganglia b) ligand-gated channel The interior is ________. This delay may be accounted for by three factors. One incoming fiber triggers responses in ever-increasing numbers the membrane potential has been reestablished. The speed of nerve impulse propagation varies in different types of cells. Unmyelinated axons do not have nodes of Ranvier, and ion channels in these axons are spread over the entire membrane surface. Nerve Impulse | Definition, Mechanism, Process & Types - A Level Biology Similarly, in the case of nerve impulse conduction, the neurons the stimulus must have a threshold value for causing the movement of ions across the length of axon (for conducting nerve impulse) by opening the voltage-gated ion channels. Because it varies in amplitude, the local potential is said to be graded. A) biogenic amine. When the action potential is over (after transmitting the nerve impulse through neuron) the cell membrane potential returns back by repolarizing the membrane. B) Absolute refractory period. This process is called repolarization. The answer involves ions, which are electrically charged atoms or molecules. In electrical transmission, the ionic current flows directly through channels that couple the cells. Which of the following is not true of graded potentials? Others are membrane proteins that, upon activation, catalyze second-messenger reactions within the postsynaptic cell; these reactions in turn open or close the ion channels. The part of a neuron that conducts impulses away from its cell body is called a(n) ________. In the polarized state, the axon membrane is more permeable to potassium ions instead of sodium ions and as a result, it causes rapid diffusion of potassium ions. Which of the following is not true of graded potentials? Neurotransmitter inactivation is carried out by a combination of three processes. The fastest conduction velocity occurs in the largest diameter nerve fibres. C) The synaptic cleft prevents an impulse from being transmitted directly from one neuron to another. Collections of nerve cell bodies outside the central nervous system ________ is a neurotransmitter of the CNS that is used by Purkinje cells of the CNS. The signal is transmitted in the form of ions and therefore it is much faster than chemical synapses. One mechanism, the sodium-potassium pump, maintains the resting potential, and another, the various ion channels, helps create the action potential. In what way does the interior surface of a cell membrane of a resting (nonconducting) . d) moves membrane potential away from threshold, Collections of nerve cell bodies outside the central nervous system are called ________. conduction to take place. Which of the following is not characteristic of neurons? Exam 4 Flashcards - Easy Notecards c. 1.21.21.2 liters Receives stimuli. Absolute refractory period The interior of the cell becomes less negative due to an influx of sodium ions. Direct-acting neurotransmitters ________. )Which neuron is a sensory neuron found in a reflex arc? D) Some ions are prevented from moving down their concentration gradients by ATP-driven pumps. True or False, Unipolar neurons have axons structurally divided into peripheral and central processes. In myelinated neurons, ion flows occur only at the nodes of Ranvier. Select the correct statement regarding synapses. Does Berkekey accept transcripts with a W on it. This makes the process of nerve impulse faster as the nerve impulse does not travel the entire length of the axon ( this happens in case of continuous conduction). A) They increase amplitude as they move away from the stimulus point. A second nerve impulse cannot be generated until ________. The interior is ________. True or False, Cell bodies of sensory neurons may be located in ganglia lying outside the central nervous system. b) amplify or enhance the effect of ACh c) ependymal cells A neuron that has as its primary function the job of connecting other neurons is called a(n) ________. When a sensory neuron is excited by some form of energy, the resulting graded potential is called a(n) ________. Which of the following neurotransmitters inhibits pain and is mimicked by morphine, heroin, and methadone? Nerve cell adhesion molecules (N-CAMs) ________. a) motor fibers that conduct nerve impulses from the CNS to smooth muscle, cardiac muscle, and glands B) destroy ACh a brief period after its release by the axon endings. 3.) The resting membrane potential refers to the non-excited state of the nerve cell at rest when no nerve impulse is being conducted. True or False, Neurons in the CNS are organized into functional groups. c) a nerve impulse occurs if the excitatory and inhibitory effects are equal, a nerve impulse occurs if the excitatory and inhibitory effects are equal, A neuron that has as its primary function the job of connecting other neurons is called a(n) ________. The flow of which type of ion into the neuron results in an action potential? In what way does the interior surface of a cell membrane of a resting (nonconducting) neuron differ from the external environment? property of being electrically coupled. F(A,B,C,D)=BD+BCD+ABC+ABCD+BDF(A, B, C, D)=B D^{\prime}+B^{\prime} C D+A B C+A B C^{\prime} D+B^{\prime} D^{\prime}F(A,B,C,D)=BD+BCD+ABC+ABCD+BD (b) Find the minimum sum of products. Automatically remove your image background. Calcium causes synaptic vesicles to fuse with the membrane, releasing their contents into the narrow space between the presynaptic and postsynaptic membranes. In what way does the interior surface of a cell membrane of a resting (nonconducting) neuron differ from the external environment? A nerve impulse, like a lightning strike, is an electrical phenomenon. A) Voltage would be measured by placing one electrode inside the membrane and another outside the membrane. Once stimulated by Ca2+, the vesicles move through the cytoplasm and fuse their membranes with the plasma membrane of the terminal. to another stimulus is the ________.A) depolarization, Strong stimuli cause the amplitude of action potentials generated to increase. The answer is 'the membrane potential has been reestablished' Ths occurs by pumping out sodium ions from the inside of the cell. Neuroglia that control the chemical environment around neurons by buffering potassium and recapturing neurotransmitters are ________. An impulse from one nerve cell is communicated to another nerve cell via the ________. At this point there exist two methods for transmitting the action potential from one cell to the other. The nerve goes through a brief refractory period before racing resting potential. The EPP is actually made up of multiple MEPPs, which arise when an activated terminal releases hundreds of neurotransmitter quanta. As a result of this, the membrane becomes hyperpolarized and have a potential difference of -90 mV. potential has been reestablished. summationD) Threshold stimulus, The nodes of Ranvier are found only on myelinated, peripheral neuron processes. Ion channel. The action potential state is based on the All or none method and has two possibilities: If the stimulus is not more than the threshold value, then there will be no action potential state across the length of the axon. Once the membrane potential is completely returned to its resting potential (when membrane potential is reestablished), the neurons become ready for second or next nerve stimulus. A nerve impulse is produced when a stimulus acts on the nerve fibre, resulting in electrochemical changes across the nerve membrane. d) act as a transmitting agent, destroy ACh a brief period after its release by the axon endings, Which of the following is false or incorrect? A&P Chapter 12 The Central Nervous System Flashcards - Easy Notecards Which group of fibers spreads impulses at up to 1 meter per second? Unipolar neurons have axons structurally divided into peripheral and Which of the following correctly describes a graded potential? When information is delivered within the CNS simultaneously by different parts of the neural pathway, the process is called ________ processing. Quiz #11 (Nervous Tissue) Flashcards | Chegg.com True or False, A positive feedback cycle is the main force in the generation of graded potentials at receptor ends. (nonconducting) neuron differ from the external environment? Neurophysiology Practice #2 - A second nerve impulse cannot be Due to this, the transmission of nerve impulses is slower than electrical synapses. 33) A second nerve impulse cannot be generated until _____. This is because a larger axon diminishes the ion-leakage out of the axon. Which of the following is not a special characteristic of neurons? The generation of a second action in some neurons can only After neurotransmitter is released from the presynaptic terminal, it diffuses across the synaptic cleft and binds to receptor proteins on the postsynaptic membrane. The first channels to open are the sodium ion channels, which allow sodium ions to enter the cell. Which of the following is correct? The all-or-none phenomenon as applied to nerve conduction states that the whole nerve cell must be stimulated for conduction to take place. Second, they are taken back into the presynaptic terminal by transmitter-sensitive transport molecules. C) diphasic impulses It is called the action potential because the positive charge then flows through the cytoplasm, activating sodium channels along the entire length of the nerve fibre. a) nuclei The greater the influx of positive chargeand, consequently, depolarization of the membranethe higher the grade. Ca2+ is known to be sequestered by certain organelles within the terminal, including the endoplasmic reticulum. d) oligodendrocytes, David N. Shier, Jackie L. Butler, Ricki Lewis, Charles Welsh, Cynthia Prentice-Craver, David Shier, Jackie Butler, Ricki Lewis, Human Anatomy and Physiology Laboratory Manual (Main Version). These tiny electrical events, called miniature end-plate potentials (MEPPs), or miniature postsynaptic potentials (MPSPs), are caused by the random release of single quanta of neurotransmitter from a resting presynaptic terminal. Which of the choices below describes the ANS? Nerve impulse was discovered by British Scientist Lord Adrian in the 1930s. Na+ channels open: . Figure \(\PageIndex{4}\)shows the change in potential of the axon membrane during an action potential. A nerve impulse is thus an important signal transduction mode for triggering a response in major body parts due to a strong stimulus. These electrochemical changes cause depolarization of the membrane resulting in the generation of nerve impulses. Strong stimuli cause Outline how a signal is transmitted from a presynaptic cell to a postsynaptic cell at a chemical synapse. The synapse more common in embryonic nervous tissue than in adults is the ________. The concentration of sodium ions is about 16 times more outside the axon than inside. KNR 181 Ch 11 Study Guide Flashcards | Chegg.com d) cells with gap junctions use chemical synapses, the synaptic cleft prevents an impulse from being transmitted directly from one neuron to another, Which of the following is true about the movement of ions across excitable living membranes? It is uncertain what happens in the time between Ca2+ entry and transmitter release. The action potential is +40 mV. the membrane There the vesicles lose their coats, are probably refilled with neurotransmitter, and pinch off from the cisternae to become synaptic vesicles once more. Depolarization The specific period during which potassium ions diffuse out of the neuron due to a change in membrane permeability. B) the impulse would spread bidirectionally. after-discharge circuitD) Converging circuit, Cell bodies of sensory neurons may be located in ganglia lying He pushes off the boards with a force of 9.0 N. What is his resulting acceleration? Which of the following will occur when an excitatory postsynaptic potential (EPSP) is being generated on the dendritic membrane? Which of the following is not a Relative refractory period An exceptionally strong stimulus can trigger a response Repolarization The specific period during which potassium ions diffuse out of the neuron due to a change in membrane permeability. a second nerve impulse cannot be generated until___ the membrane potential has been reestablished: an impulse from one nerve cell is communicated to another nerve cell via the___ synapse: neuroglia that control the chemical enviroment around neurons by buffering potassium and recapturing neurotransmitters are___ astrocytes The polarization state is also known as the Unstimulated or non-conductive state. If the stimulus is more than the threshold value, then it will generate a nerve impulse that will travel across the entire length of the axon. True or False, The two major classes of graded potentials are transmitter potentials and receptor potentials. The transmission of a nerve impulse from one neuron to another neuron is achieved by a synaptic connection (synapse) between them. Legal. Whether acting upon ion channels directly or indirectly, the neurotransmitter molecules cause a sudden change in the permeability of the membrane to specific ions. a single type of channel will open, permitting simultaneous flow of sodium and potassium. Saltatory conduction increases the speed at which a nerve signal is conducted down the length of an axon. Subthreshold Stimulus An insufficient stimulus Spatial Summation After repolarization there is a period during which a second action potential cannot be initiated, no matter how large a stimulus current is applied to the neuron. a stimulus? interior is ________.A) negatively charged and contains less sodium, B) positively charged and contains less sodium, C) negatively charged and contains more sodium, D) positively charged and contains more sodium, If a motor neuron in the body were stimulated by an electrode placed A) are crucial for the development of neural connections. What is the role of acetylcholinesterase? At the threshold, voltage-dependent sodium channels become fully activated, and Na+ pours into the cell. a) sodium gates in the membrane can open in response to electrical potential changes Chapter 11 Flashcards - Easy Notecards A&P ch 11 quiz - Subjecto.com B) Neurotransmitter receptors are located on the axons terminals of cells. The threshold stimulus must be strong enough to change the resting membrane potential into action membrane potential. 3.) Which of the following describes the nervous system integrative function? The most common potential change is depolarization, caused by a net influx of cations (usually Na+). Explain how an electrical signal in a presynaptic neuron causes the transmission of a chemical signal at the synapse. myelin sheath Which ion channel opens in response to a change in membrane potential and participates in generation and conduction of action potentials? True or False, Saltatory conduction occurs because of the presence of salt (NaCl) around the neuron. the inferior is ____ negatively charged and contains less sodium 30 analyzes sensory information, stores information, makes decisions. Which of the following is not a function of astrocytes? Nerve impulse propagates by jumping from one node of Ranvier to the next. (a) Plot the following function on a Karnaugh map. conduction states that the whole nerve cell must be stimulated for An excitatory neurotransmitter secreted by motor neurons innervating skeletal muscle is ________. It refers to a graded potential state because a threshold stimulus of about -55mV causes a change in the membrane potential. During this period, the membrane prepares itself for the conduction of the second stimulus after restoring the original resting state. if the ventral nerve root of a spinal is never destroyed a person would lose.. . This helps in maintaining the membrane potential and thus favors faster nerve impulses. A gap between Schwann cells in the peripheral system is called a(n) ________. Saltatory conduction is made possible by ________. C) motor fibers that conduct nerve impulses from the CNS to smooth muscle, cardiac muscle, and glands. They may also be removed from the terminal by exchange with extracellular Na+a mechanism known to occur at some neuronal membranes. C) control the chemical environment around neurons, D) guide the migration of young neurons, synapse formation, and sodium and potassium. Select the correct statement regarding synapses. Until potassium channels close, the number of potassium ions that have moved across the membrane is enough to restore the initial polarized potential state. D) the membrane potential has been reestablished. impulse would move to the axon terminal only, C) the impulse would move to the axon terminal only, and the muscle b. True or False, Strong stimuli cause the amplitude of action potentials generated to increase. 2.) The resulting increase in positive charge inside the cell (up to about +40 mV) starts the action potential. Dendrites- Receive the signals from the axon ends. D) Cells with gap junctions use chemical synapses, The period after an initial stimulus when a neuron is not sensitive A) erratic transmission of nerve impulses. A single type of channel will open, permitting simultaneous flow of ________ potentials are short-lived, local changes in membrane potential that can be either depolarized or hyperpolarized. Another factor is the temperature of the nerve fibre. As instantaneous as the opening of sodium channels at threshold potential is their closing at the peak of action potential. These sites have the advantage of being readily accessible for recording by electrodesespecially the squid synapse, which is large enough that electrodes can be inserted directly into the presynaptic terminal and postsynaptic fibre. A stimulus would be you burning your finger or bumping your arm. Which ion channel opens in response to a change in membrane potential and participates in the generation and conduction of action potentials? b) opens K+ or Cl- channels C) Spinal reflexes are an example of serial processing. Which of the following is not a chemical class of neurotransmitters? The resting membrane potential of the nerve cell is -70 mV. This is called the absolute refractory period, and it is followed by a relative refractory period, during which another action potential can be generated, but only by a greater stimulus current than that originally needed. Calcium ions. synaptic vesicles to the axonal membrane. Signals are propagated along the nerve fibres in the form of nerve impulses. ________. The term central nervous system refers to the ________. This is called sodium inactivation, and it is caused by gates within the channel that are sensitive to depolarization.
