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30 Cards in this Set
- Front
- Back
Central Nervous System |
complex of nerve tissues controlling the activities of the body; cns, specifically, brain and spinal cord |
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Peripheral Nervous System |
the nervous system outside the brain and spinal cord |
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neuron |
specialized cells for the conduction of information |
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cell body |
contains the nucleus and most organelles |
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axons |
conduct impulses away from cell body toward other neurons or effectors |
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dendrites |
extensions leading toward the cell body; brings signals to cell bodies from other neurons |
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myelin sheath |
a fatty white substance that surrounds the axon of some nerve cells, protecting them and speeding messages along |
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sensory neuron |
take information to the CNS, have sensory receptors |
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interneuron
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completely embedded w/in the CNS; receives input from sensory and other interneurons and sends feedback back through motor neurons
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motor neuron
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takes messages from CNS t effector organs (muscles, glands or organs) |
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Describe the transmission of a nerve impulse along a neuron. |
Sensory receptor transmits impulse to cord. Synapses with interneurons in cord (integration) and up to the brain. Transmitted to motor neuron. Motor neuron carries impulse to effector muscle. |
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What is resting potential? How is it maintained? |
the amount of energy waiting to be used within a neuron; maintained by sodium potassium pumps which actively transport Na out of and K into a synapse |
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What is action potential? |
a rapid change in polarity across an axonal membrane as a nerve impulse occurs; "all or nothing" phenomenon |
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List the membrane structures involved in an action potential and the role of each. |
1. Sodium Gates- open first, Na flows down concentration gradient into an axon. Axon changes from negative to positive, "depolarize" 2. Potassium Gates- open 2nd, K flows down concentration gradient to outside axon. AP inside post synapse resumes negative charge. |
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refractory period |
time during which sodium gates in a presynapse are unable to open, preventing backflow of synapses |
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Name 2 neurotransmitters. |
ACl (acetycholine) and norepinepherine |
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synaptic cleft |
a junction between 2 nerve cells through which neurotransmitters jump from synapse to synapse |
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Explain the transmission that takes place within a synapse. |
one way transmission, from presynaptic to post synaptic; neurotransmitters are chemical messengers that cross from synapse through synaptic cleft and into the next neuron |
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Describe spinal nerves. |
the spine extends from the base of the brain. White matter, myelinated, surrounds grey matter; takes messages to the brain. Grey matter, unmyelinated, takes messages back from the brain. Dorsal root and ganglion (sensory) stem from back of spine; ventral (motor) from in front. |
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Relate the following parts of the spinal cord: central canal, grey matter, and white matter. |
the spinal cord has 3 layers. the innermost part is the central canal, center of "H" grey matter (unmyelinated cell bodies of neurons). the outer most part is called white matter, myelinated neurons. |
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Describe the reflex arc. |
automatic responses to a stimulus |
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Function of: ventricles |
hollow interconnecting cavities in the brain that connect with the hollow central canal of the spinal cord; produce and hold cerebrospinal fluid, the substance that cushions and protects the CNS |
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Function of: brain stem |
contains midbrain, pons and medulla oblongata |
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Function of: cerebrum |
the largest portion of the brain in humans that receives sensory input, processes it, and commands voluntary motor responses |
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Function of: grey matter |
contains brain's cell bodies of neurons; includes regions of the brain involved in muscle control and sensory perception |
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Function of: white matter (fibers) |
connects grey matter through axons |
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Function of: cerebellum |
receives sensory input from joints, muscles and other sensory pathways about position of body parts; maintains body posture |
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Function of: medulla oblongata |
regulates vital functions (heartbeat, breathing, blood pressure) and contains the reflex centers (vomiting, coughing, sneezing, hiccuping, and swallowing)omit "limbic system and higher mental functions" |
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Explain the autonomic nervous system. |
a part of the PNS subdivided categorically between the sympathetic "fight of flight" and the parsympethetic "rest and digest"; automatic and involuntary impulses |
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Name the 2 divisions of the autonomic nervous system and what they are responsible for. |
*Sympathetic, "fight or flight" *Parasympathetic, "rest and digest" |