Term
| The central nervous system |
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Definition
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Term
| peripheral nervous system |
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Definition
| the nerves connecting the brain and spinal cord to other parts of the body (all nerves) |
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Term
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Definition
| division of the human nervous system that regulates involuntary actions |
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Term
| What are the three main parts of a neuron? |
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Definition
| dendrites, cell body, axon |
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Term
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Definition
| nerve cell including its processes(axons and dendrites) |
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Term
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Definition
| conduct impulses to the cell body of the neuron |
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Term
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Definition
| conducts impulses away from the cell body of the neuron |
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Term
| neurons are classified according to? |
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Definition
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Term
| What are the 3 different types of neurons? |
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Definition
| sensory, motor, and interneurons |
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Term
| What do sensory neurons do? |
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Definition
| conduct impulses to the spinal cord and brain |
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Term
| What do motor neurons do? |
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Definition
| conduct impulses away from brain and spinal cord to muscles and glands |
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Term
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Definition
| conduct impulses from sensory to neurons to motor neurons |
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Term
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Definition
| they are supporting cells and they bring the cells of the nervous tissue together structurally and fuctionally |
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Term
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Definition
| bundle of peripheral axons |
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Term
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Definition
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Term
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Definition
| brain or cord tissue composed primarily of myelinated axons(tracts) |
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Term
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Definition
| brain or cord tissue composed primarily of cell bodies and unmyelinated fibers |
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Term
| What kind of tissue is nerve coverings? |
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Definition
| Fibrous connective tissue |
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Term
| what does the endoneurium do? |
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Definition
| surrounds individual fibers within a nerve |
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Term
| what does the perineurium do? |
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Definition
| surrounds a group of nerve fibers (fascicle) |
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Term
| What does the epineurium do? |
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Definition
| surrounds the entire nerve |
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Term
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Definition
| allows an impulse to travel in only one direction |
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Term
| What happens in a reflex arc? |
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Definition
| nerve impulses are conducted from receptors to effectors over neuron pathways or reflex arc |
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Term
| conduction by a reflex arc results in? |
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Definition
| a reflex(that is contraction by a muscle or secretion by a gland |
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Term
| What is the simplest reflex arc? |
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Definition
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Term
| What does a two-neuron arc consist of? |
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Definition
| sensory neurons synapsing in the spinal cord with motor neurons |
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Term
| What does the three neuron arc consist of? |
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Definition
| sensory neurons synapsing in the spinal cord with interneurons that synapse with motor neurons |
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Term
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Definition
| self-propagating wave of electrical disturbance that travels along the surface of a neuron membrane |
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Term
| What is the mechanism of nerve impulses? |
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Definition
1. a stimulus triggers the opening of Na+ channels in the plasma membrane of the neuron
2. inward movement of positive sodium ions leaves a slight excess of negative ions outside at a stimulated point; marks the beginning of a nerve impulse |
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Term
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Definition
| junction between adjacent neurons |
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Term
| What are the 2 communicating systems of the body? |
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Definition
| nervous system and the endocrine system |
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Term
| How are the nervous system and the endocrine system different? |
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Definition
nervous system transmits info very rapidly by nerve impulses conducted from one body area to another
the endocrine system transmits info more slowly by chemical secretion and circulated throughout the body |
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Term
| What are the organs of the nervous system? |
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Definition
1.brain and spinal cord
2. nerves of the body
3.specialized sense organs such as eyes and ears
4. microscopic sense organs like the ones in the skin |
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Term
| What are the 2 types of cells found in the nervous system? |
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Definition
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Term
neurons conduct______
glia____neurons |
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Definition
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Term
| Sensory neurons can also be called______neurons |
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Definition
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Term
| motor neurons can be called______neurons |
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Definition
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Term
| Interneurons can be called____or_____neurons |
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Definition
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Term
| what is myelin? what forms it? |
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Definition
lipoid substance(white and fatty) found in the myelin sheath around some nerve fibers
-scwann cells |
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Term
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Definition
| wrap around some axons outside the CNS |
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Term
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Definition
| axons outside the cns that are surrounded by a segmented wrapping of myelin |
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Term
| What are nodes of Ranvier? |
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Definition
| indentations between adjacent scwann cells |
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Term
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Definition
| outer cell membrane of a scwann cell |
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Term
| Which has the potential to regenerate the brain and spinal cord or the PNS? why? |
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Definition
| Pns bc the brain and spinal cord have no neurilemma which plays a significant role in regeneration of cut and injured axons |
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Term
| What is action potentials? |
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Definition
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Term
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Definition
| a region of unmyelinated nerve tissue (PNS) |
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Term
| What happens at the synapse? |
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Definition
1. the nerve impulse stops at the synapse
2.chemical signals are sent across the gap
3.then the impulse continues along the dendrites,cell body, and axon of the motor neuron
4. then the motor neuron forms a synapse with the effector |
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Term
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Definition
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Term
| What is the effector? 2 types? |
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Definition
an organ that puts the nerve signals into effect(the responding organ)
-muscles or glands |
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Term
| what is a withdrawal reflex? |
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Definition
| a reflex that moves the body part away from the an irritating stimulus |
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Term
| All interneurons lie where? |
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Definition
| within the gray matter of the brain or spinal cord |
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Term
| how does a nerve impulse travel? |
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Definition
1. they have to be intitiated by a stimulus which is pressure temp or chemical reaction
2.the membrane of each neuron has a positive outside and a negative inside.
3.when a section of the membrane is stimulated Na+ rushes inward and it moves on down the line |
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Term
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Definition
| when a nerve impulse encounters myelin and jumps from one mode of ranvier to the next |
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Term
| What 3 structures make up a synapse? |
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Definition
1. synaptic knob
2. synaptic cleft
3.the plasma membrane of the postsynaptic neuron |
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Term
| presynaptic neuron? postsynaptic neuron? |
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Definition
1. a neuron situated proximal (nearest) to a synapse
2.a neuron situated distal to the synapse |
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Term
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Definition
| tiny bulge at the end of a terminal branch of a presynaptic nuerons axon |
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Term
| each synaptic knob contains what? |
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Definition
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Term
| What is the synpatic cleft? |
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Definition
| space between the a synaptic knob and the plasma membrane of a postsynaptic neuron |
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Term
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Definition
| chemicals in which neurons communicate |
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