Direct diffusion of ions through these junctions allows the action potential to be transmitted with little or no delay or distortion, in effect synchronizing the response of an entire group of neurons. The transmitter molecules are then expelled from the vesicles into the synaptic cleft. True or False, Myelination of the nerve fibers in the central nervous system is the job of the oligodendrocyte. This Myelin sheath has regular gaps, where it is not present, called nodes of Ranvier. They may also be removed from the terminal by exchange with extracellular Na+a mechanism known to occur at some neuronal membranes. The period after an initial stimulus when a neuron is not sensitive to another stimulus is the ________. Receives stimuli. phase labeled D? The LibreTexts libraries arePowered by NICE CXone Expertand are supported by the Department of Education Open Textbook Pilot Project, the UC Davis Office of the Provost, the UC Davis Library, the California State University Affordable Learning Solutions Program, and Merlot. 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 B) Neurotransmitter receptors are located on the axons terminals of cells. This problem has been solved! are found only on myelinated, peripheral neuron processes. 33) A second nerve impulse cannot be generated until _____. This is where the transmission of a nerve impulse to another cell occurs. B) open ion channels to provoke rapid responses. This area is called the synaptic cleft. The speed of nerve impulse propagation varies in different types of cells. This delay may be accounted for by three factors. Which of the following is true about the movement of ions across excitable living membranes? A second nerve impulse cannot be generated until _____. A) the membrane potential has been reestablished B) the Na ions have been pumped back into the cell C) proteins have been resynthesized D) all sodium gates are closed. Whether acting upon ion channels directly or indirectly, the neurotransmitter molecules cause a sudden change in the permeability of the membrane to specific ions. Schwann cells are functionally similar to ________. (B). through voltage-gated channels. Why was the decision Roe v. Wade important for feminists? Which of the following will occur when an excitatory postsynaptic In what way does the interior surface of a cell membrane of a resting 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. An impulse from one nerve cell is communicated to another nerve cell via the ________. The change in membrane potential results in the cell becoming depolarized. For the transmission of a nerve impulse, the stages are below: Before going into the details of the process of nerve impulse transmission, lets first discuss action and resting potential states. What event is depicted in the structure labeled A? The nerve goes through a brief refractory period before racing resting potential. potential has been reestablished. 4.) Select the correct statement regarding synapses. True or False, Strong stimuli cause the amplitude of action potentials generated to increase. The point at which an impulse from one nerve cell is communicated to another nerve cell is the ________. 3.) Which of the following is not a structural feature of a neuron? a) excitatory potential c) ependymal cells A single type of channel will open, permitting simultaneous flow of The action potential is a result of the movement of ions in and out of the cell. impulse would move to the axon terminal only, C) the impulse would move to the axon terminal only, and the muscle Which ion channel opens in response to a change in membrane potential and participates in the generation and conduction of action potentials? 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). Neuroglia that control the chemical environment around neurons by The membrane of the presynaptic terminal contains voltage-dependent calcium channels that open when the membrane is depolarized by a nerve impulse, allowing Ca2+ to diffuse into the terminal along its concentration gradient. Signup as a free member below and you'll be brought back to this page to try the sample materials before you buy. It is a change in the resting state of the neuron. A) Voltage would be measured by placing one electrode inside the membrane and another outside the membrane. 3.) negatively charged and contains less sodium. Beginning at the resting potential of a neuron (for instance, 75 mV), a local potential can be of any grade up to the threshold potential (for instance, 58 mV). Ion channel. are crucial for the development of neural connections. The term central nervous system refers to the ________. True or False, Action potentials can be generated by virtually all cells of the body because all cells possess cell membranes. after-discharge circuitD) Converging circuit, Cell bodies of sensory neurons may be located in ganglia lying During the refractory period, another action potential cannot be generated. True or False, Enkephalins and endorphins are peptides that act like morphine. True or False, Reflexes are rapid, automatic responses to stimuli. a. The part of the neuron that normally receives stimuli is called ________. When the voltage has the required number of electron particles it conducts current. See answer (1) Copy. A second nerve impulse cannot be generated until: the refractory period: In what way does the interior surface of a cell membrane of a resting (nonconducting) neuron differ from the external environment? B) the impulse would spread bidirectionally. Saltatory conduction increases the speed at which a nerve signal is conducted down the length of an axon. Because the neurotransmitter chemicals are packed into separate, almost identically sized vesicles, their release into the synaptic cleft is said to be quantalthat is, they are expelled in parcels, each vesicle adding its contents incrementally to the contents released from other parcels. A nerve impulse is similar to a lightning strike. True or False, Cell bodies of sensory neurons may be located in ganglia lying outside the central nervous system. - Studocu Neurons and their thresholds, axons, dendrites, and Na+/K+ ATPases. c) sensory neurons that convey information from somatic receptors in the head, body wall, and limbs and from receptors from the special senses of vision, hearing, taste, and smell to the CNS A neuron that has as its primary function the job of connecting other neurons is called a(n) ________. Neurophysiology Practice #2 - A second nerve impulse cannot be generated until ________. Postsynaptic membrane. The box labeled D illustrates three mechanisms by which the effects of a neurotransmitter may be terminated. D) the membrane potential has been reestablished. Which of the following is correct? Axon diameter and degree of myelination determine nerve impulse C) The synaptic cleft prevents an impulse from being transmitted directly from one neuron to another. A) are crucial for the development of neural connections. myelin sheath Which ion channel opens in response to a change in membrane potential and participates in generation and conduction of action potentials? What is the role of acetylcholinesterase? answer choices all sodium gates are closed proteins have been resynthesized the Na ions have been pumped back into the cell the membrane potential has been reestablished Question 2 30 seconds Q. b) ligand-gated channel Na+ channels open: . The interior is Negatively charged and contains less sodium conduction to take place. If you consider the axon as an electrical wire or loop, nerve impulse that travels along the axon as current, and the charged particles ( sodium and potassium ions) as the electron particles then the process can be understood quite easily. For the following, indicate if the number of half-lives elapsed is: Nerve cell adhesion molecules (N-CAMs) ________. 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. Neurotransmitters are packed into small, membrane-bound synaptic vesicles. Plasma membrane exhibits voltage-gated Ca2+ channels. A neural circuit in which a single impulse is transmitted over and over is a ________. All of the following are true of graded potentials except that they ________. Which of the following is not true of graded potentials? Recordings from squid synapses and neuromuscular junctions of the frog reveal a delay of 0.5 to 4.0 milliseconds between the onset of action potential at the nerve terminal and action potential at the postsynaptic site. When a sensory neuron is excited by some form of energy, the second nerve impulse cannot be generated until proteins have been resynthesized the na ions DismissTry Ask an Expert Ask an Expert Sign inRegister Sign inRegister Home Which of the following is not characteristic of neurons? Figure 11.4. Identify three general types of effects neurotransmitters may have on postsynaptic cells. Select the correct statement regarding synapses. 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. Any stimulus below this intensity True or False, A stimulus traveling toward a synapse appears to open calcium channels at the presynaptic end, which in turn promotes fusion of synaptic vesicles to the axonal membrane. 3.) Signals are propagated along the nerve fibres in the form of nerve impulses. In a reflex arc, which neuron has its cell body inside the d) leakage channel, What is the role of acetylcholinesterase? A. the Na ions have been pumped back into the cell B. the membrane potential has been reestablished C. proteins have been resynthesized D. all sodium gates are closed, sort the chemical reactions based on whether they absorb or release energyI'm asking this next to the other people who did because the answer with the Also called a nerve impulse transmitted by ions Action Potential During this; an exceptionally strong stimulus can trigger a response Relative Refractory Period Numerous nerve impulses arriving at a synapse at closely time intervals exert a cumulative effect during this period Temporal Summation Between these myelinated sheaths, unmyelinated gaps are presently known as the nodes of Ranvier. A second nerve impulse cannot be generated until ________. A) the membrane potential has been reestablished B) the Na ions have been pumped back into the cell C) proteins have been resynthesized D) all sodium gates are closed the membrane potential has been reestablished Immediately after an action potential has peaked, which cellular gates open? b) sensory and motor neurons that supply the digestive tract A) Reverberating circuitB) Diverging circuitC) Parallel An inhibitory postsynaptic potential (IPSP) is associated with ________. A stimulus would be you burning your finger or bumping your arm. a single type of channel will open, permitting simultaneous flow of sodium and potassium. Both of the ion channels then close, and the sodium-potassium pump restores the resting potential of -70 mV. 16. B) A single type of channel will open, permitting simultaneous flow of sodium and potassium. and participates in the generation and conduction of action 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. D) Some ions are prevented from moving down their concentration gradients by ATP-driven pumps. 4.) Collections of nerve cell bodies outside the central nervous system True or False, A positive feedback cycle is the main force in the generation of graded potentials at receptor ends. In electrical transmission, the ionic current flows directly through channels that couple the cells.
March 11, 2023