Where does the parasympathetic branch of the nervous system arise from quizlet?
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Hole's Human Anatomy and Physiology15th EditionDavid Shier, Jackie Butler, Ricki Lewis 1,950 solutions Complete each sentence by dragging a word to the proper position. Then arrange the sentences into the order of occurrence of motor impulses in the ANS. 1. Also known as the craniosacral division, the parasympathetic nervous system has fibers exiting the CNS at the medulla oblongata. 2. Action potentials travel down the preganglionic nerve fibers of the vagus nerve, towards the effector organs. 3. These impulses arrive at the cardiac plexus where secretion of acetylcholine creates an action potential in the postganglionic neuron. 4. The impulse arrives relatively quickly at the heart, as parasympathetic postganglionic fibers are short compared to sympathetic postganglionic fibers. 5. Action potentials arriving at the sinoatrial and atrioventricular nodes of the heart cause acetylcholine to be released. 6. This parasympathetic neurotransmitter causes a decrease in heart rate and contractility. Recommended textbook solutions
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Seeley's Essentials of Anatomy and Physiology9th EditionMcGraw-Hill Education 512 solutions The ANS consists of two divisions, parasympathetic and sympathetic, which normally exert antagonistic effects on many of the same target organs. The parasympathetic division (the rest-digest system) conserves body energy and maintains body activities at basal levels. Parasympathetic effects include constricted pupils, glandular secretion, increased digestive tract motility, and smooth muscle activity leading to elimination of feces and urine. The sympathetic division prepares the body for activity (the fight-or-flight system). Sympathetic responses include dilated pupils, increased heart rate, increased blood pressure, dilated bronchioles of the lungs, increased blood glucose levels, and sweating. During exercise, sympathetic vasoconstriction shunts blood from the skin and digestive viscera to the heart, brain, and skeletal muscles. 1. An action potential in a motor neuron is propagated to the axon terminal (terminal button). 2. This local action potential triggers the opening of voltage-gated Ca2+ channels and the subsequent entry of Ca2+ into the terminal button. 3. Ca2+ triggers the release of acetylcholine (ACh) by exocytosis from a portion of the vesicles. 4. ACh diffuses across the space separating the nerve and muscle cells and binds with receptor-channels specific for it on the motor end plate of the muscle cell membrane. 5. This binding brings about the opening of these nonspecific cation channels, leading to a relatively large movement of Na+ into the muscle cell compared to a smaller movement of K+ outward. 6. The result is an end-plate potential. Local current flow occurs between the depolarized end plate and the adjacent membrane. 7. This local current flow opens voltage-gated Na+ channels in the adjacent membrane. 8. The resultant Na+ entry reduces the potential to threshold, initiating an action potential, which is propagated throughout the muscle fiber. 9. ACh is subsequently destroyed by acetylcholinesterase, an enzyme located on the motor end-plate membrane, terminating the muscle cell's response. Where does the parasympathetic nervous system arise from?The parasympathetic nervous system is described as originating in the craniosacral region, that is, from the brainstem and also the sacral plexus.
Where does the parasympathetic neurons originate from quizlet?The parasympathetic nervous system, which originates in the brain and sacral region of the spinal cord, has long cholinergic preganglionic fibers and short cholinergic postganglionic fibers.
Where on the spinal cord does the parasympathetic branch of the nervous system branch from quizlet?Parasympathetic nerves are associated with the cranial and sacral regions of the spinal cord, whereas sympathetic nerves are associated with the thoracic and lumbar regions. Stimulating the organs of digestion is a parasympathetic response.
Where does the sympathetic branch of the nervous system arise from quizlet?Preganglionic neurons of the sympathetic nervous system arise from the thoracic and lumbar regions of the spinal cord. The sympathetic nervous system has short preganglionic and long postganglionic fibers, so autonomic ganglia reside near the spinal cord.
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