Explain how the spinal nerves are grouped and numbered.?
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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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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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The axial skeleton forms the central axis of the body. It consists of the skull, the vertebral column, the ribs and the sternum or breastbone.  There are 80 bones total in the axial skeleton, and I'm sorry but I'm not going to type them all out for you.  I will, however, provide you with some links so that you can see what they are if you need to know all 80.  They have great diagrams.\n\nhttp://webschoolsolutions.com/patts/systems/skeleton.htm#axial\nhttp://www.botany.uwc.ac.za/sci_ed/grade10/manphys/axial.htm
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There is no F.  The vertebrae are divided into C (cervical), T (thorax), L (lumbar), S (sacral) and O (coccyx)
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the motor neurons in the peripheral nervous system.
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It is the peripheral nervous system.  It is a system of nerves that are outside the brain and spinal cord (the ones that extend into your arms and legs and into your chest and abdomen).
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here are the anwsers in order from top to bottom \n-T\n-T\n-F\n-F \nhope this helps
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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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Sensory = afferent and dorsal\nMotor = efferent and ventral
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hey! read a fish book. they always how a diagram of disecting parts or body anatomys. hint: for more info... go to this website:
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...\n\nThe bony arches of the vertebrae have two types of projection: one, called the spinous process, extends backwards from the arch in the mid-line (it is these spinous processes which are felt all down the back); the other, the transverse processes, extend laterally on each side from a position posterior to the intervertebral foramen.\n\nIf one now considers the vertebral column as a structural unit, one sees the column of vertebral bodies anteriorly, joined by the intervertebral discs as bricks are joined by mortar, with the bony arches behind. These bony arches have paired pedicles which enclose the intervertebral foramina on each side just behind the vertebral bodies. Farther back on each side one encounters the transverse processes, and finally in the mid-line of the back, the spinous processes. The whole column is bound together with various ligaments of great strength, on the anterior and posterior surfaces of the vertebral bodies and on the bony arches, their processes, and their joints. The muscles further strengthen and cushion the vertebral column.\n\nWithin the vertebral column, the circles formed by the bony arches described above are aligned to constitute a canal, called the spinal canal. The spinal canal contains the spinal cord, the trunk of nerves which is in continuity with the brain above. Neither the brain nor the spinal cord are in contact with the bones which protect them. These delicate nerve structures are completely enveloped by three concentric membranes, the meninges; respectively, the dura mater, the arachnoid, and the pia mater.\n\n...
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http://en.wikipedia.org/wiki/Neurons
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This is called the "sensory homunculus" and the "motor homunculus" diagrams.  Do a google image search for either of these terms:\n\nHere are many versions of the "sensory homunculus" diagram.\nhttp://images.google.com/images?svnum=10&hl=en&lr=&q=sensory+homunculus&btnG=Search\n\nAnd here's the "motor homunculus" diagram:\nhttp://images.google.com/images?svnum=10&hl=en&lr=&q=motor+homunculus&btnG=Search\n\nI found a version here:\nhttp://en.wikipedia.org/wiki/Trigeminal_nerve#Touch.2FPosition_Sensation\n\nThe following page has a more explanatory version, but the above is more up-to-date:\nhttp://www.karger.com/gazette/67/Field/art_4.htm
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all the many nerves attached to your spinal cord, i think.
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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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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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its this thing called reflex arc. see this pic n u might get it. it has stuff to do with neurons n i dont feel like writing the whole crap.\nlol thnx hmmm didnt see wat is said :) its actually\nhttp://dtc.pima.edu/~biology/201alpha/lesson10/reflexarc.jpg