a. a second nerve impulse cannot be generated until: the membrane potential has been re-established: in what way does the interior surface of a cell membrane of a resting (nonconducting) neuron differ from the external enviroment? property of being electrically coupled. serotonin C) nitric oxide D) endorphin, A neuron that has as its primary function the job of connecting other c) voltage-gated channel B) A nerve impulse occurs if the excitatory and inhibitory effects are equal. The signal is transmitted in the form of ions and therefore it is much faster than chemical synapses. Sodium is the principal ion in the fluid outside of cells, and potassium is the principal ion in the fluid inside of cells. Signup as a free member below and you'll be brought back to this page to try the sample materials before you buy. Which result of the stimulus applied is the likely cause of the It persists for only 2 milliseconds. The action potential is +40 mV. Schwann cells are functionally similar to ________. True or False, A positive feedback cycle is the main force in the generation of graded potentials at receptor ends. During the repolarization state, efflux of potassium ions through the potassium channel occurs. This site is using cookies under cookie policy . The point at which an impulse from one nerve cell is communicated to another nerve cell is the ________. concentrated at the nodes of Ranvier. One is the vertebrate neuromuscular junction, and the other is the giant synapse of the squid Loligo. 3. If somehow the synaptic gap doesnt allow the passage of nerve impulse, the transmission of nerve impulse will not occur and consequently required response too. repolarization occurs with the flow of K+ out of the cell. )Which neuron is a sensory neuron found in a reflex arc? Explain how and why an action potential occurs. B) are crucial in the production of neurotransmitters, C) are crucial for the development of neural connections. True or False, A graded potential that is the result of a neurotransmitter released into the synapse between two neurons is called a postsynaptic potential. b) dendrite are crucial for the development of neural connections. Which of the following neurotransmitters inhibits pain and is mimicked by morphine, heroin, and methadone? This process is called repolarization. the amplitude of action potentials generated to increase. The first channels to open are the sodium ion channels, which allow sodium ions to enter the cell. One mechanism, the sodium-potassium pump, maintains the resting potential, and another, the various ion channels, helps create the action potential. The resting membrane potential refers to the non-excited state of the nerve cell at rest when no nerve impulse is being conducted. Any distraction in this process can have drastic effects on the body. Seeley's Essentials of Anatomy and Physiology, Andrew Russo, Cinnamon VanPutte, Jennifer Regan, EXAM 2 Q's and A's from other persons test, three half-lives the membrane potential has been re-established: all sodium gates are closed. ii. Choose the statement that is most correct about membrane potential. C) Spinal reflexes are an example of serial processing. True or False, In myelinated axons the voltage-regulated sodium channels are concentrated at the nodes of Ranvier. returned it's base level or even more negative. 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. The interior is _____, negatively charged and contains less sodium, The substance released at axon terminals to propagate a nervous impulse is called a(n) _____. Thus, no sodium ions will move inside the membrane. analyzes sensory information, stores information, makes decisions. Ciliated CNS neuroglia that play an active role in moving the cerebrospinal fluid are called ________. The sodium-potassium pump is a mechanism of active transport that moves sodium ions out of cells and potassium ions into cells. Which of the following is not a special characteristic of neurons? potential (EPSP) is being generated on the dendritic membrane?A) Third, they are metabolized into inactive compounds by enzymes in the synaptic cleft. spinal cord? the inferior is ____ negatively charged and contains less sodium 30 The speed of nerve impulse propagation varies in different types of cells. Which of the following is an excitatory neurotransmitter secreted by motor neurons innervating skeletal muscle? When a stimulus is applied to resting membrane, sodium ions freely pass inside the cell and membrane is now said to be in depolarized phase. In a reflex arc, which neuron has its cell body inside the Axon- Helps in the propagation of nerve impulses to the target cell. Which of the following describes the nervous system integrative function? A second nerve impulse cannot be generated until ________. the membrane potential has been reestablished. What does the central nervous system use to determine the strength of a stimulus? What generally determines the effects of a neurotransmitter on a postsynaptic cell? 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. However, the velocity of conduction along the nerve fibre is dependent upon several factors. B) Sodium gates will open first, then close as potassium gates open. The part of a neuron that conducts impulses away from its cell body is called a(n) ________. At the neuromuscular junction, brief depolarizations measuring no more than one millivolt can be observed in the postsynaptic muscle membrane, even when it is at rest. Besides, Myelin Sheath also helps in accelerating the rate of signal conduction (about 20 times). Nerve impulse can be defined as a signal that transmits along the nerve fibers. The all-or-none phenomenon as applied to nerve conduction states that the whole nerve cell must be stimulated for conduction to take place. Mastering A&P Human Anatomy & Physiology 10th Edition Marieb. Which of the following is not a structural feature of a neuron? It is a short duration of time during which a new nerve impulse cannot be generated in a neuron, after initiation of a previous action potential. D) the membrane potential has been reestablished. In order a nerve impulse to be generated there needs to be a stimulus. Collections of nerve cell bodies outside the central nervous system are called ________. A) The release of neurotransmitter molecules gives cells the The sodium-potassium pump moves both ions from areas of lower to higher concentration, using energy in ATP and carrier proteins in the cell membrane. sodium and potassium. Receives stimuli. 1. Tecle, with a mass of 65.0 kg, is standing by the boards at the side of an ice skating rink. 3.) Neurotransmitter inactivation is carried out by a combination of three processes. Select the correct statement about synapses. In myelinated neurons, ion flows occur only at the nodes of Ranvier. Exactly which ions now permeate the membrane vary according to the neurotransmitters and their receptors (see the section Neurotransmitters and neuromodulators), but the net result of a change in ion diffusion is a change in electrical potential across the membrane. This page titled 11.4: Nerve Impulses is shared under a CK-12 license and was authored, remixed, and/or curated by Suzanne Wakim & Mandeep Grewal via source content that was edited to the style and standards of the LibreTexts platform; a detailed edit history is available upon request. 3.) summationD) Threshold stimulus, The nodes of Ranvier are found only on myelinated, peripheral neuron processes. The interior is Negatively charged and contains less sodium Which of the following is true about the movement of ions across excitable living membranes? A second nerve impulse cannot be generated until ____, the membrane potential has been reestablished. Which of the following is not a D) Cells with gap junctions use chemical synapses C. 11 B) Neurotransmitter receptors are located on the axons terminals of cells. What is the role of acetylcholinesterase? This is called repolarization of the membrane. Due to the difference in the concentration of ions inside and outside the membrane, a potential gradient is established ranging between -20-200mV ( in the case of humans, the potential gradient in the polarized state is nearly -70mV). interior is ________. Immediately after an action potential has peaked, which cellular gates open? central processes. D) erratic transmission of nerve impulses. b) Schwann cells A) The release of neurotransmitter molecules gives cells the property of being electrically coupled. Particularly the ions included in this process are sodium and potassium ions. frequency of action potentials 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) ________. Nerve impulse can be defined as a signal that transmits along the nerve fibers. Figure 11.4. Which of the following is correct? second nerve impulse CANNOT be generated until membrane potential has been reestablished 29 interior surface of a cell membrane of a resting (nonconducting) neuron differ from the external environment? potentials?A) ligand-gated channel. These chemical signals are neurotransmitters. When information is delivered within the CNS simultaneously by different parts of the neural pathway, the process is called ________ processing. It is a static state and both the sodium and potassium channels are closed during this state maintaining a high concentration of sodium ions outside and high potassium ions concentration inside the cell. Neurophysiology Practice #2 - A second nerve impulse cannot be generated until ________. (nonconducting) neuron differ from the external environment? Figure \(\PageIndex{3}\)shows in greater detail how the sodium-potassium pump works. This series of activations, by propagating the action potential along the fibre with virtually no reduction in amplitude, gives the nerve impulse its regenerative property. As a result, the action potential signal "jumps" along the axon membrane from node to node rather than spreading smoothly along the membrane, as they do in axons that do not have a myelin sheath. - Studocu Neurons and their thresholds, axons, dendrites, and Na+/K+ ATPases. True or False, Strong stimuli cause the amplitude of action potentials generated to increase. The period after an initial stimulus when a neuron is not sensitive to another stimulus is the ________. a) afforestation neuron Join over 22,000 learners who have passed their exams thanks to us! The EPP is actually made up of multiple MEPPs, which arise when an activated terminal releases hundreds of neurotransmitter quanta. Temperature directly correlates with the transmission of nerve impulses. As a result of this, the membrane becomes hyperpolarized and have a potential difference of -90 mV. This is because We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739.