Trace the sympathetic nerve pathway through a ganglion to an effector.?
462432
The sympathetic nerves arise in the brain in the reticular formation, a diffuse set of nuclei (cell bodies in the brain or spinal cord) and send axons (bioelectrical transmission lines) the the lateral horn of the spinal cord.  The reticular formation receives incoming pain signals as well as higher input from the hypothalamus, cortex and elsewhere.  The axons descending to the lateral horn snynape (form chemical connections that communicate with the next neuron by chemicals known as neurotransmitters) with the cell bodies of motor neurons.  These motor neurons send myelinated (myelin is a biological insulator) axons to the ganglia (collections of cell bodies outside the brain and spinal cord) for the sympathetic nervous system.  These ganglia include a long chain that entends from the cervical to the lumbar regions, plus other ganglia in the head and adbominal cavity.  This synapse typically releases the neurotransmitter, acetylcholine, which acts on nicotinic type "N" receptors - nicotinic-ganglionic receptors.   Nicotinic "N' receptors are distinguished from nicotinic "M" receptors (the neuromuscular junction) that serve skeletal muscle by differing responsiveness to pharmacological agents.  The post-synaptic (cell that receives the chemical signal) neurons are not mylenated and project to the visceral organs, skin, and blood vessels where they release neurotransmitters (norepinephrine or, in the case of skin, acetylcholine) that act on the effector organs.
346325
A reflex action is a stereotyped (involuntary) motor response elicited by a defined stimulus. 1 A reflex action is mediated via the reflex arc.\n\nA reflex arc is the neural pathway that mediates a reflex. It generally does not involve the brain. In higher animals it is composed of a spinal "reflex integration center" composed of interneurons to connect affector (sensory stimulation) and effector (response) signals. While the reflex generation may be initiated by nociceptive input, extensive processing takes place within the spinal cord. The neural connection from the primary sensory neurons to the motor neurons is a poly-synaptic pathway (Andersen).\n\nIn lower animals reflex interneurons not necessarily inolve the spinal cord, see e.g., lateral giant neuron of crayfish.\n\nA reflex to a stimulus is almost simultaneous, as the reflex arc doesn't involve the brain at all.\nA reflex action or reflex is a biological control system linking stimulus to response and mediated by a reflex arc. Reflexes can be built-in or learned. It occurs very quickly before thinking. Before the message is sent to the brain the spine picks it up and sends it back to the muscle causing spasm.\n\nSimple reflex\nA simple reflex is entirely automatic and involves no learning.\n\nAn example is the escape reflex (e.g., the sudden withdrawal of a hand in response to a pain stimulus), or the patellar reflex (the jerking of a leg when the kneecap is tapped). Sensory cells (receptors) in the stimulated body part send signals to the spinal cord along a sensory nerve cell. Within the spine a reflex arc switches the signals straight back to the muscles of the body (in this case the arm or the leg) (effectors) via an intermediate nerve cell and then a motor nerve cell; contraction of the leg occurs, and the muscle contracts (the arm or leg jerks upwards). Only three nerve cells are involved, and the brain is only aware of the response after it has taken place. Such reflex arcs are particularly common in animals, and have a high survival value, enabling organisms to take rapid action to avoid potential danger.\n\nConditioned reflex\nA conditioned reflex involves the modification of a reflex action in response to experience (learning). A stimulus that produces a simple reflex response becomes linked with another, possibly unrelated, stimulus. For example, a dog may salivate (a reflex action) when it sees its owner remove a tin-opener from a drawer because it has learned to associate that stimulus with the stimulus of being fed.\n\nReaction time\nFor a reflex, reaction time or latency is the time from the onset of a stimulus until the organism
176044
When u insert two electrodes to measure impulse travelling along a nerve, two recordings are obtained.\nThis is because recording occurs, once when the impulse reaches the site of the first electrode, Secondly, the reading is obtained when the impulse reaches the second electrode site.\nThis recording is known Biphasic record.
786890
veins transmit deoxygenised blood toward the heart (except for pulmonary veins), while nerves transmit electrical impulses from the brain to sensory organs, or vice versa. \n\nsimple as that! peace.
91844
When we perceive an immediate danger, our brain processes incoming signal and sends a message to the whole body to mobilize resources for defense ("fight") or retreat ("flight"). The major recipient of these brain signals are adrenal glands, which secrete hormone epinephrine (adrenalin). Adrenalin is released into blood stream, binds to its receptors on various cells and initiates a  "launch" sequence: it makes liver to release glucose into blood, it elevates heart rate and increases blood pressure, diverts blood flow from at the moment non-essential organs (like digestive tract) to muscles etc. It happens in the matter of seconds, so the individual becomes ready to face or evade the incoming danger.
201239
The dorsal root ganglion relays somatasesensory information from that afferent sensory nerve fibers to the spinal cord and ultimately sensory cortex of the brain in the parietal cortex.\n\nFor example, if you burn your little finger, the pain receptors will stimulate the sensory portion of the ulnar nerve. The ulnar nerve will "fire" with an action potential into the brachial plexus and those cords will carry that stimulation up to the dorsal root ganglions at the specific cervical levels for the ulnar nerve (C7 & C8 ish). The dorsal root will relay that stimulus to the dorsal sensory tracts of the spinal cord where it will head toward the brain; crossing over to the opposite side of the head at the brainstem.
738730
Your "thought" of movement starts in the precentral gyrus, the signal travels to the cerebellum via pontine nuclei, then the action potential is sent, but it is sloppy movement and still needs calibration.  This is done after afferent signals from the proprioceptive neurons combine with the first set of efferents and the 2 are compared.  The signals then are refined by the precentral gyrus and secondary impusles for the same movement are again sent down the pathway.
883112
Just an overview.\nthere are nerves that are attached to the muscles.\nSome also are controlled by hormones. The nervous system signals to the glands to secrete hormones. \n\nJust remember that the nervous system has major divisions: the central nervous system (brain and spinal cord), autonomic nervous system (sympathetic and parasympathetic), peripheral nervous student (nerves). Those nerves are all spread out through our body. Always remember that those divisions of the nervous system communicate with each other.\n\nYou must really read books to know. I can't place all the details here.
201083
I'm not quite sure what you are asking, but I think the answer you want is that each ganglion contains the cell bodies of the sensory neurones.\nUnipolar motor neurones have their cell bodies within the spinal cord.
157160
Somatic pathways send signals to your body that a person has conscious control over.  These pathways are responsible for moving muscles.  example: running, making a fist, moving your eyeball, etc.\nAutonomic pathways send signals to your body that a person does not have conscious control over.  These pathways are responsible for your reflexs.  example: when you stick your hand in a fire, your hand will pull back before your brain/consciousness sends a message to pull back the hand, heart beating, lungs breathing, etc.\n\nThe overall difference is the component parts of the pathways (what kind of neurons) and to what part of the brain the pathways lead to (motor cortex/etc or brainstem)
276026
"As the action potential envelops the bouton (the terminal bouton at the end of the axon), the synaptic vesicles attach to the bouton membrane at the active zone.  Once attached they release their chemical messenger into the synaptic cleft where it diffuses to the post synaptic membrane.  There the chemical messenger combines with a receptor protein, a process that alters the ionic conductance and consequently the membrane potential of the post synaptic cell.  This may initiate an action potential in the post synaptic neuron."\n\nTo summarize:\nThe action potential arrives at the synaptic junction.  There it stimulates the release of the chemical messenger, known as a neurotransmitter, into the synaptic cleft.  If enough neurotransmitter chemicals cross the synaptic cleft and attach to receptors on the 2nd neuron, a new action potential is initiated in the 2nd neuron.
360558
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?
325686
shingles......thye follow the nerve
802253
nervous system\n\nendocrine system
1108277
"Many nerve cells are of the basic type illustrated above. Some kind of stimulus triggers an electric discharge of the cell which is analogous to the discharge of a capacitor. This produces an electrical pulse on the order of 50-70 millivolts called an action potential. The electrical impulse propagates down the fiber-like extension of the nerve cell (the axon). The speed of transmission depends upon the size of the fiber, but is on the order of tens of meters per second - not the speed of light transmission that occurs with electrical signals on wires. Once the signal reaches the axon terminal bundle, it may be transmitted to a neighboring nerve cell with the action of a chemical neurotransmitter. "\n\ni studied this once when i was in matriculation college. i found this quite useful. hope this will help ya..\n\ngood luck
548091
try this link and it should answer your question it is with diagram!\n\nhttp://en.wikipedia.org/wiki/Central_nervous_system
696929
Neuronal activity is very complex, while influx of one molecule into the hilloc causes its depolarisation in one neuron it leads to hyperpolarisation in another.  With sufficient depolarisation and build up of Excitation K+ and Na+ activity beggins.  for every 2K+ brought into the cell 3Na+ are emitted from the cell.  This causes a cascade down the cell due to comple intracellular events of the depolarization being propagated down the axon.  This is electrical activity and so can be detected with electrodes.  There are many different types of proteins some of which are voltage sensitive along the length of the axon.  The local change in voltage activates these other channels leading to further depolarization and propogation moving along on.  This allows the depolarization to effectivley jump from one node of ranvier to the next (none insulated parts of neuron).  Talking of insulation, the mylin sheeth is made of schwan cells which promots signal propogation much like plastic covering copper.\n\nThe internal signals are very complex and would require a diagram, but involve Gproteins and Ca++.......