![]() Therefore, preganglionic SNS fibers are short, while postganglionic SNS fibers are long as they have the longer route to pass in order to reach their target tissues. SNS ganglia are found close to the SNS centers, in contrast with PSNS ganglia which are farther from the PSNS centers. ![]() A ganglion is a neural tissue outside of the CNS which comprises of the neuronal bodies of the second-order neurons whose axons (postganglionic fibers) provide autonomic innervation to the organs. Their axons (preganglionic fibers) synapse with the bodies of the postganglionic (second-order) neurons, which are found within autonomic ganglia. Preganglionic (first-order) neurons are found within the gray matter of the CNS. This article will discuss the anatomy and the function of the autonomic nervous system. Orthostatic (postural) hypotension, dysfunctions of the urinary bladder, impotency Decreased gland secretion, except for sweat glands Contraction of cardiac muscle by stimulating conduction system Sacral outflow: pelvic splanchnic nerves – supply descending colon, sigmoid colon, rectum, bladder, penis or clitoris Cranial outflow: branches of oculomotor (CN III), facial (CN VII), glossopharyngeal (CN IX), and vagus (CN X) nerves – supply head, neck, heart, larynx, trachea, bronchi, lungs, liver, gallbladder, stomach, pancreas, kidney, small intestine, proximal large intestine Ganglia: ciliary, pterygopalatine, otic, submandibular, abdominopelvic ganglia on the walls of the abdominopelvic organs Lumbar splanchnic nerves (T12-元) – supply pelvic visceraĬenters: brainstem (cranial outflow), S2-S4 segments of spinal cord (sacral outflow) The greater, lesser, and the least thoracic splanchnic nerves (T7-T11) – supply abdominal viscera Cardiopulmonary splanchnic nerves (T4-T6) – supply thoracic viscera Periarterial carotid nerve plexuses (T1-T3) – supply head and neck Ganglia: paravertebral ganglia (sympathetic trunk), prevertebral (collateral/preaortic) ganglia Key facts about the autonomic nervous systemĬenters: intermediolateral columns of spinal cord T1-L2/元 Smooth muscle (walls of the blood vessels, walls of the hollow organs). ![]() Functionally, the ANS is divided into sympathetic (SNS) and parasympathetic (PSNS) nervous systems. Morphologically, the ANS is divided into central and peripheral parts.
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