Concept explainers
Introduction:
The autonomic nervous system comprises of sympathetic and parasympathetic divisions. Both these systems innervate the visceral organs and have their own effects on the target organs. The sympathetic system operates in the heart, lungs, and smooth muscles and it executes its effect on flight or fight response to create organs excitation. On the contrary, the parasympathetic system innervates the same organ and it effects executes during rest or digest mode. The innervation of an organ by sympathetic and parasympathetic system is said to be the dual innervation. In some cases, the autonomic nervous system does not need the dual innervation. There are some cases of organs, where there is no need of dual innervation.
Want to see the full answer?
Check out a sample textbook solutionChapter 15 Solutions
Anatomy and Physiology
- Select all of the statements from the list below that are true. Within a single axon, an action potential is always of the same magnitude. (In other words, it always looks the same on a trace of the membrane potential.) All excitatory post-synaptic potentials trigger an action potential. Graded potentials are always hyperpolarizing. The action potential always moves in one direction along an axon. Integration of sensory information is a major function of the central nervous system. All axons in the body are myelinated.arrow_forwarda channel can be gated mechanically, voltage or by a ligand. When you hear a sound all three of these type channels are being utilized. Explain generally where/how each of these channels are being utilized starting from hearing the sound, through travelling down a nerve to transmission to another nerve.arrow_forwardMultiple sclerosis (MS) is a disorder that causes the destruction of myelin sheaths surrounding neurons. People with MS display many symptoms, including slurred speech, double vision, and poor muscle coordination. What is the direct effect of MS on nerve impulse transmission? Select one: The movement of impulses along neurons is slower than normal. Dendrites cannot be stimulated by acetylcholine, therefore impulses are not generated in neurons. The threshold level of stimulation for neurons is greater than normal. Axons cannot sectete acetylcholine, therefore impulses are not able to travel across synapses. Oarrow_forward
- Which of the following statements is true? Chemical messengers within cells are always the main determinant of the effector response. Dual innervation is always present in all organs and glands; one branch enhances the function or secretion, while the other branch inhibits it. The beating of the heart is regulated only by the sympathetic division. Some blood vessels contain alpha adrenergic receptors that cause vasoconstriction in the presence of epinephrine, whereas others have beta adrenergic receptors that cause vasodilation in the presence of epinephrine.arrow_forwardUsing the cardiovascular, respiratory and digestive systems as examples, explain how dual innervation regulates the function of each system.arrow_forwardA laboratory experiment is set up where you have two fully functional nerves properly aligned so that it potentially can transmit an action potential through a synapse to the second nerve. The buffer outside the cells contain Na+, H+ and Cl- as the only inorganic ions. When you stimulate the nerve, surprisingly the second nerve does not respond. What is the most likely explanation for the failure of the second nerve response? State why you chose your answer. a. The lack of K+ in the buffer prevents propagation of the action potential b. Neurotransmitter is not being released into the synaptic space. c. An action potential can only be initiated by opening a ligand-gated channel. d. Although neurotransmitter is released, it is unable to stimulate opening of the second nerve' ligand-gated channel. e. Repolarization of the axon does not occur in this buffer.arrow_forward
- Two separate post-synaptic interneurons receive synaptic potentials from afferent neurons in the periphery. The dendrites of one these interneurons receive an excitatory post-synaptic potential (EPSP) and an inhibitory post-synaptic potential (IPSP) of equal magnitude at the same time. The dendrites of the other interneuron receive one excitatory post-synaptic potential that is the same sized as the EPSP and IPSP received by the other interneuronarrow_forwardDefine the term reciprocal innervation?arrow_forwardWhy are there multiple receptor subtypes for eachneurotransmitter? Why not a few receptors and lots ofneurotransmitters acting on each receptor?arrow_forward
- Figure 35.26 Which of the following statements is false? The parasympathetic pathway is responsible for relaxing the body, while the sympathetic pathway is responsible for preparing for an emergency. Most preganglionic neurons in the sympathetic pathway originate in the spinal cord. Slowing of the heartbeat is a parasympathetic response. Parasympathetic neurons are responsible for releasing norepinephrine on the target organ, while sympathetic neurons are responsible for releasing acetylcholine.arrow_forwardWhich of the following statements regarding postsynaptic potentials is correct? IPSPs are the result of influx of potassium ions and EPSPs are the result of efflux of sodium ions. IPSPs are the result of efflux of potassium ions and EPSPs are the result of influx of chloride ions. IPSPs are the result of efflux of potassium ions and EPSPs are the result of influx of sodium ions. IPSPs are the result of efflux of chloride ions and EPSPs are the result of efflux of calcium ions.arrow_forwardWhy are many drugs that are used to treat nervous system diseases or to affect brain function targeted to specific receptors rather than particular neurotransmitters?arrow_forward
- Human Physiology: From Cells to Systems (MindTap ...BiologyISBN:9781285866932Author:Lauralee SherwoodPublisher:Cengage LearningConcepts of BiologyBiologyISBN:9781938168116Author:Samantha Fowler, Rebecca Roush, James WisePublisher:OpenStax CollegeBiology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStax