Term
| Spinal segments C 1-8 receive information from where? |
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Definition
| Back of head, neck, shoulders, hands, and most of the skin of the arms. |
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Term
| Spinal segments T 1-12 receive information from where? |
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Definition
| Most of the skin of the arms, trunk of the body. |
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Term
| Spinal segments L 1-5 receive information from where? |
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Definition
| Waist, thighs, upper and lower legs, and partly feet |
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Term
| Spinal segments S1-5 and sacrococc. segment receive information from where? |
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Definition
| Back of legs, butt, and most of the skin of feet. |
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Term
| The transfer of information occurs only in ___ of the spinal cord? |
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Definition
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Term
| The axons that carry information make up the ______ of the spinal cord? |
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Definition
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Term
| What is responsible for fine motor control? |
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Definition
| The lateral corticospinal tract |
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Term
| What is resonsible for the gross motor control? |
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Definition
| The ventral corticospinal tract. |
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Term
| How are the neurons that make up the sensory component wired? Discriminative sensation.. |
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Definition
1st order: Touch and pressure receptions > Large myelinated a-alpha and beta fibers > thru white matter > Dorsal column-med, lemniscal pathways > gray matter or medulla
2nd order: Arcuate fibers cause to switch sides> white matter or midbrain> grey matter of Ventrolat nucleus of thalamus
Third order neurons: Precentral gyrus |
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Term
| How are the neurons that make up the sensory component wired? Non- discriminative... |
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Definition
Pain, hot and cold and proprioseption of jt.
First order neuron: |
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Term
| Name the sensory receptors found on the skin. |
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Definition
| Free nerve endings, Meissner corpuscle, End bulof of Krause, Pacinian corpuscle, Ruffini ending ( Muscle spindle and Golgi Tendon Organ are found in muscle) |
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Term
| What will take place to the permeability of the receptor plasma membrane to sodium if a finger is laid lightly at the back of the hand? |
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Definition
| Increase as it wants to propagate stimulus to somatosensory cortex. |
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Term
| What will take place with the sodium entry into the cell if a finger is laid lightly at the back of the hand? |
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Definition
| Increase as increase in plasma membrane permeability. |
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Term
| What will change in the membrane potential of the receptor if a finger is laid lightly at the back of the hand? |
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Definition
| Membrane potential inside the cell will increase as positive charges increase in the ICF. |
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Term
| If there is a change in potential to the parameters if a finger is laid lightly at the back of the hand what is the potential called? |
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Definition
| Receptor potential: entry of Na+ into the receptor region which causes the depolarization of the membrane of the receptor. |
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Term
| List the steps in the transduction of an incident sensory stimulus from the point of contact to the generation of the action potential on the nerve fiber. |
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Definition
| 1) Initial stimulus 2) increase in permeability of receptor membrane to Na+ 3) passive Na+ channels open 4) increase in membrane potential 5) creation of receptor potential 6)opening of voltage gated sodium channels 7) propagation of depolarization towards trigger point at node of ranvier 8) reaching threshold stimulus 9) depolarization to threshold potential and create AP |
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Term
| Indicate the changes that will take place in the size of receptor potential when the receptor potential increases. |
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Definition
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Term
| Indicate the changes that will take place in the size of action potential when the receptor potential increases. |
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Definition
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Term
| Indicate the change that will take place in the frequence of receptor potential when the receptor potential increases. |
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Definition
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Term
| Indicate the change that will take place in the action potential in receptor when the receptor potential increases. |
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Definition
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Term
| Does a receptor potential always give rise to an action potential whenever it is produced? |
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Definition
| No- the receptor potential decremental spread may result in insufficient depolarization (sub threshold stimulus) |
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Term
| At what part of the neuron is the receptor potential generated? |
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Definition
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Term
| In what type of neuron is the receptive field generated? (peripheral sensory, central sensory, or motor neuron)? |
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Definition
| Peripheral sensory neuron |
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Term
| List the sequence of events that describes how an AP on one spot on the membrane gives rise to another on an adjacent part or at another node on the nerve fiber. |
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Definition
| 1. Depolarization 2. wave of Na+ influx in down concentration gradient 3. Repolarization behind it with K+ efflux 4. Depolarization of entire region 5. If strong enough when reachines next node in myelinated or next spot in unmyelinated- create AP w/ opening of voltage gated ion channels |
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Term
| If the generation of action potential in the nervefiber in the intate individual unidirection or bi-direction? Explain. |
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Definition
| Unidirection b/c refractory periods prevent the backward propagation of APs. The area behind the AP is repolarized with K outflow. |
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Term
| How does the increase Ca2+ in ECF affect the excitability of the nerve fiber membrane? |
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Definition
| Increased excitability as more calcium can flow in and cause calmodulin activation and synapsin activation resulting in greater NT release. |
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Term
| How does the decrease ECF Ca2+ affect the excitability of the nerve fiber membrane? |
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Definition
| Decrease in excitability as decrease Ca2+ it means less ability to activate calmodulin results in less synapsin phosphorylation and less NT release. |
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Term
| How does High ECF K+ affect the excitability of the nerve fiber membrane? |
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Definition
| Increased excitation as easier to depolarize as more is depolarized. |
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Term
| How does low ECF K+ affect the excitability of the nerve fiber membrane? |
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Definition
| Decreased excitability due to hyperpolarization. |
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Term
| How does local anesthetics affect the excitability of the nerve fiber membrane? |
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Definition
| Decreased excitability as they stabilize the local lipid bi-layer and don't allow for Na+ passage. |
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Term
| What does the speed of conduction of action potentials depend on? |
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Definition
| Myelination-Myelinated fibers conduct impulses faster (5x-50x) bc AP only occurs at nodes of Ranvier which have high concentration of voltage-gated ion channels. |
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Term
| Define saltatory conduction. What type of neuron is involved in this process? |
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Definition
| It involves action potential jumping from node to node between myelinated neurons. |
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Term
| Arrange the fibers in the correct sequence of their fiber sizes and conduction velocities. |
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Definition
| A-alpha, a beta, A gamma, A delta, C |
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Term
| What type of relationship exists between the size of the fiber and condution velocity (direct or inverse)? |
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Definition
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Term
| What type of information does A-alpha- Beta fibers carry? |
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Definition
| receptor carrying info from the encapsulated endings used in 2 point discrimination, vibration and conscious proprioception. |
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Term
| What type of information does A- delta fibers carry? |
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Definition
| associated with cooling and 1st pain. |
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Term
| What type of information does C fibers carry? |
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Definition
| convey 2nd pain and warming > post-ganglionic autonomics |
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Term
| List the sequence of events that take place in the presynaptic terminals when action potential arrives at the axon terminals and how these give rise to exocytosis of the neurotransmitters. |
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Definition
| 1. AP depolarizes the terminal 2. Open voltage-gated Ca2+ channels 3. Ca2+ rushes into cell and down concentration gradient 4. Ca2+ interacts with calmodulin 5. which activates protein kinase 6. induces phosphorylation of synapsin 7. Causes migration of vesicles containing NT to the part of the presynaptic membrance which function as release site 8. Transmitter binds to presynaptic membrane- release NT into synaptic cleft by exocyosis. |
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Term
| List the events that will take place in the postsynaptic neuron when the following neurotransmitters bind to the postsynaptic membrane (from beginning of binding to the change in membrane potential): Glutamate, ACH, Asparate, Substance R, Enkcephalins |
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Definition
1. Travel across synaptic cleft 2. Binds to the postsynaptic membrane 3. open chemically gated ion channel 4. Na+ flows in 5. Excitatory depolarization of region (EPSP)
6. Decrementally spreads towards the axon hillock 7. once reach axon hillock, if strong enough stimulus- open voltage gated Na+ channels and cause AP. |
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Term
| List the events that will take place in the postsynaptic neuron when the following neurotransmitters bind to the postsynaptic membrane: GABA, Glycine, Norepinephrine, Dopamine, Serotonin |
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Definition
| 1. Travel across synaptic cleft 2. Bind to the postsynaptic membrane 3. Open chemmically gated ion channels 4. Causes K+ to flow out and Cl- to flow in 5. Hyperpolarization of membrane 6. IPSP |
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Term
| Define excitatory postsynaptic potentials. In what parts of the neuron are they generated? |
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Definition
| EPSPs are excitatory depolarizations of the receptive region of the post synaptic neuron on the dendrite and soma. |
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Term
| Does the EPSP have anything in common with receptor potential? |
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Definition
| 1. Local depolarization with decremental spread with Na+ influx towards site causing AP generation 2. Does not generate a nerve impulse on receptive area 3. Must reach trigger point. |
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Term
| What are the differences between the EPSP and receptor potential? |
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Definition
| 1. EPSP occurs as a result of opening chemically gated ion channels on the post synaptic membrane in response to Ach, Glutamate, Asparate, Substance P, Enkcephalins 2. receptor potentials occur on the presynaptic neuron as a result of opening of passive Na+ channels. |
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Term
| Define inhibitory postsynaptic potential. What part of the neuron is it generated? |
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Definition
| IPSP is a wave of K+ efflux and Cl= that hyperpolarizes the membrane in response to NT opening of chemically gated Na+ channels in response to NT : NE, Dopamine, Serotonin, and GABA |
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Term
| Does IPSP increase or decrease the chances of a postsynaptic neuron to generate an AP? |
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Definition
| Decrease as the membrane becomes hyperpolarized and therefore creates more difficulty to reach threshold of depolarization at the axon hillock therefore no voltage gated Na+ channels open and therefore no resultant influx of Na+. |
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Term
| Will the discharge of single presynaptic terminal always give rise to an action potential in a postsynaptic neuron in the CNS? |
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Definition
| No, the potential will spread decdrementally down the axons and the intensity may not be large enough to produce an AP. The stimulus may activate inhibitory NT such as GABA, NE, D2, and SE |
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Term
| Will the number of sensory receptor units activated increase or decrease as the intensity of the stimulus increases? |
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Definition
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Term
| Will the size of receptor potential increase or decrease as the intensity of the stimulus increases? |
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Definition
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Term
| Will the frequency of action potentials in the nerve fiber increase or decrease as the intensity of the stimulus increases? |
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Definition
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Term
| Will the size of the EPSP increase or decrease as the intensity of the stimulus increases? |
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Definition
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Term
| Will the size of the fiber increase or decrease as the intensity of hte stimulus increases? |
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Definition
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Term
| Define the concept of divergence in the CNS. Is it a presynaptic or a postsynaptic phenomenon? What role does it play in the transmission of information in the CNS? |
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Definition
| Divergence in the CNS results from the idea of creating IPSP or EPSP as a result of inhibitory or excitatory NT binding to eliminate unnecessary information and focus on important stimuli only and occurs at the postsynaptic neuron. |
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Term
| Define spatial summation. Is it a presynaptic or postsynaptic event? |
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Definition
| involves the firing of multiple pre-synaptic terminals to create a gret enough potential to create a post synaptic potential on the post synaptic neuron. The process is originated on the presynaptic neurons; however the summation itself occurs on the post synaptic dendrites. |
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Term
| What effect (increase or decrease) does spatial summation have on the size of the EPSP; IPSP? |
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Definition
| Increases the size and there are multiple inputs occuring which summate and increse the amplitude of the EPSP. |
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