Do you know the parts of the nervous system that are involved in a spinal reflex?
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Depends on the reflex. Myotatic is the simplest. One synapse.\n\nAfferent Ia axon (originating in a muscle spindle) enters the spinal cord and synapses on an alpha motor neuron innervating the same muscle, causing it to fire. This reflex mediates the "knee-jerk" your doctor checks for.\n\nhttp://academic.uofs.edu/faculty/kosmahle1/courses/pt351/lect351/reflxarc.JPG\n\nExample in picture form.
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Afferent (sensory) nerves originate from the dorsal (back) horn. They are classified as pseudounipolar cells and the cell body of the neuron is a bit farther from the dendrites. The dorsal root ganglion is a collection of the cell bodies for the sensory pseudounipolar cells. All sensory nerves have ganglia.
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They're named and numbered according to the spinal vertebrae. Each pair of spinal nerves exits the spine just below the pedicle (bone that comes out from the main body of the vertebra and goes backwards to form the lamina, or bony covering over the back of the spinal cord.)\n\nCervical - there are 7 cervical vertebrae (called C1-C7) and 8 pairs of cervical spinal nerves (this is the only exception in the system). C1 nerves come out on TOP of the C1 vertebra, C2 nerves on top of C2 etc., C7 on top of C7 and C8 just below the pedicle of C7, between the C7 and T1 vertebrae (see below.)\n\nThoracic - there are 12 thoracic vertebrae (T1-T12) and hence 12 pairs of thoracic spinal nerves.\n\nLumbar - 5 lumbar vertebrae, ditto.\n\nSacral - the vertebrae in the sacrum are fused together but there are still little holes for the nerves to come out. There are 5 sacral nerves, S1-S5.
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I. COMPARISON OF SOMATIC AND AUTONOMIC NERVOUS SYSTEMS (ANS)\n\n     A. Sensory neurons of the somatic nervous system receive input from the special senses, general somatic senses, and proprioceptors; sensory neurons of the ANS receive input from the special senses, general visceral senses, and general somatic senses.\n\n     B. The somatic nervous system operates under conscious control; the ANS operates without conscious control.\n    \n     C. The axons of the motor neurons of the somatic nervous system extend from the CNS synapse directly to an effector and release acetylcholine, whereas autonomic pathways consist of two sets of motor (efferent) neurons.\n\n        1. The axon of the first (preganglionic) motor neuron of the ANS extends from the CNS and synapses in a ganglion with the second neuron.\n        2. The second (postganglionic) motor neuron synapses on an effector. Preganglionic fibers release the neurotransmitter acetylcholine and postganglionic fibers release acetylcholine or norepinephrine. \n\n     D. Somatic nervous system effectors are skeletal muscles, and ANS effectors include cardiac and smooth muscle, and glands.\n    \n     E. The somatic nervous system responds to neurotransmitters as excitation while the ANS response to neurotransmitters is excitation or inhibition.\n\n     F. A summary of the similarities of and differences between the somatic and autonomic nervous systems is presented.\n\n     G. The output (efferent) part of the ANS is divided into two principal parts: the sympathetic and the parasympathetic. Organs that receive impulses from both sympathetic and parasympathetic fibers are said to have dual innervation. III. \n\nANATOMY OF AUTONOMIC MOTOR PATHWAYS\n\n     A. Overview\n\n        1. Preganglionic neurons are myelinated; postganglionic neurons are unmyelinated.\n         2. The first of two autonomic motor neurons is called a preganglionic neuron.\n             a. Its cell body is in the brain or spinal cord.\n             b. Its myelinated axon, called a preganglionic fiber pathway, passes out of the CNS as part of a cranial or spinal nerve, later separating from the nerve and extending to an autonomic ganglion where it synapses with the postganglionic neuron.\n        3. The postganglionic neuron pathway, the second neuron in the autonomic motor circuit, lies entirely outside the CNS.\n            a. Its cell body and dendrites are located in an autonomic ganglion, where it makes synapses with one or more preganglionic fibers.\n            b. The axon of a postganglionic neuron, the postganglionic fiber, is unmyelinated and terminates in a visceral effector. \n         4. The cell bodies of sympathetic preganglionic neurons are in the lateral gray homs of the 12 thoracic and first 2 or 3 lumbar segments; the cell bodies of parasympathetic preganglionic neurons are in cranial nerve nuclei (III, VII, IX, and X) in the brain stem and lateral gray horns of the second through fourth sacral segments of the cord.\n         5. Autonomic ganglia are classified as:\n              a. sympathetic trunk (vertebral chain) ganglia (on both sides of spinal column)\n              b. prevertebral (collateral) ganglia (anterior to spinal column);\n              c. parasympathetic terminal (intramural) ganglia (near or inside visceral effectors). 6. In addition to autonomic ganglia, the ANS contains autonomic plexuses. \n\n     B. Sympathetic and Parasympathetic Divisions\n\n         1. Sympathetic preganglionic neurons synapses with postganglionic neurons in ganglia of the sympathetic trunk or prevertebral ganglia.\n         2. Parasympathetic preganglionic neurons synapses with postganglionic neurons in terminal ganglia.\n        3. The salient anatomical features of the sympathetic and parasympathetic divisions are compared. \n\nTransmission of Autonomic Stimuli\n\nLike other nerves, those of the autonomic nervous system convey their messages to the appropriate end organs (blood vessels, viscera,
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The brain is part of the nervous system.  The smallest component of the nervous system are axons, which have a head and a tail.  Millions of these line up head to tail and form the nerve endings in your body.  In the space between each head and tail (called a synapse) chemicals can flow.  When something happens (you prick yourself), an axon signals chemicals to flow between the synapse, activate the next axon, and the next until the message reaches your brain and you react.  Different drugs affect the ability for these chemicals to flow across the synapse (speeding up, slowing down, or not at all) or wipe out axons all together leaving gaps in the message chain.
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Your question is hard to understand, but here is some basic information about the nervous system in humans/animals.  \n\n\nThe nervous system of an animal coordinates the activity of the muscles, monitors the organs, constructs and also stops input from the senses, and initiates actions. Prominent participants in a nervous system include neurons and nerves, which play roles in such coordination.\n\nThe nervous system of vertebrate animals are often divided into a central nervous system (CNS) and the peripheral nervous system (PNS). The CNS consists of the brain and spinal cord. The PNS consists of all other nerves and neurons that do not lie within the CNS. The large majority of what are commonly called nerves (which are actually axonal processes of nerve cells) are considered to be PNS. The peripheral nervous system is divided into the somatic nervous system and the autonomic nervous system. For example, the human brain is part of the nervous system.
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During muscle contraction the strands of collagen are stretched as the muscle shortens. This stretching deforms the terminals of the Ib afferent axon, opening stretch-sensitive cation channels. As a result, the axon is depolarized and fires nerve impulses up to the central nervous system via the spinal cord. The action potential frequency signals the force being developed within the muscle.\n\nThis sensory feedback plays an important role in spinal reflexes and in the central control of muscle contraction. Specifically, it is postulated that because a Golgi tendon organ exists in serial connection with muscle fibers, it can measure the tension that each muscle contraction builds up. The Ib afferent axon synapses with interneurons within the spinal cord and also relays information to the brain. One of the main spinal reflexes receiving an input from the Ib afferent is the autogenic inhibition reflex, which is involved with the regulation of the force profile of on-going muscle contractions.\n\nThe ascending pathways to the cerebellum are the dorsal and ventral spinocerebellar tracts and are involved in the cerebellar regulation of movement.
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Autonomous nerve-sys.-regulates our organs and vital functions.\nNerve endings-contain neurotransmitters in  its fluid.\nneurons-bundles of nerve cells.\nElectrical impulses-together with chem. transmits messages.\nsynapse-Impulse jump to dendrites from here.
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Smooth muscle. It is part of the autonomic nervous system. This muscle helps to control the pressure and flow in the arteries of the body.
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Sympathetic nervous system
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try this link and it should answer your question it is with diagram!\n\nhttp://en.wikipedia.org/wiki/Central_nervous_system
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Plesse go to this website \n\nhttp://www.umm.edu/spinecenter/education/anatomy_and_function_of_the_spine.html
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Reflex responses actually occur in the spinal cord; so the flight reflex, if already triggered (i.e., the chicken sees that axe a'comin') could keep firing even after the brain is no longer in the picture. \n\nThe chicken has a limited amount of time, of course, since it's bleeding out, but during that period, anything that's happening on the reflex level still can happen.\n\nAn old biology experiment (I take that back - after searching, it's apparently still being done) involved essentially cutting off a frog's head in such a manner that there was no brain left, but the spinal cord and peripheral nerves were intact. Said frog would turn itself back over if rolled onto its back, and would jerk its foot away from a shock, demonstrating that the reflexes are handled in the spinal cord, not the brain. (Sorry about your head, pal.)
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Your brain is mostly damaged in the part where a certain part of the spinal cord is damaged. Neurons do not regenerate. They get killed and don't come back. Nerve cells don't normally regenerate themselves.
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Sympathetic:\n\nDivision: Preganglionic neurons in spinal cord\n\nAutonomic outflow from the thoracic and high lumbar segments of the spinal cord\n\nGenerally excitatory in action\n\nHeart: increases rate\nAdrenal glands: stimulates secretion\nLiver: increases glucose output\n\nParasympathetic:\n\nDivision: Fibers leave through cranial nerves and sacral segments of spinal cord \n\nAutonomic outflow from the cranial nerves, low lumbar and sacral spinal cord\n\nGenerally inhibitory in action\n\nBronchi: causes constriction\nSalivary glands: increases secretion\nHeart: decreases rate\n\n\nI don't quite know what you mean by receptors and subdivisions, however. The ANS controls most involuntary organs in the body, and any organ that is controlled by the ANS must have receptors for it to act upon. Is the reference to epinepherine and norepinepherine receptors, or something else?
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There are twelve pairs of thoracic spinal nerves.\nThe intercostal muscles, the muscles of the thorax (pectoralis major and minor, latissimus dorsi, etc.), and the paraspinal, psoas, abdominal and oblique muscles.   The upper thoracic spinal nerves are also part of the brachial plexus, which innervates the arms.
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There are a lot of physical and psychological reactions that could be called reflexes.  Can you narrow down the question a little?