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Related Flashcards
Cards In This Set
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What is a nerve pathway?
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A nerve pathway are the 'directions' an impulse goes through and the simplest pathway is a reflex arc.
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What is the general concept of the pathway; it's parts and directions?
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The general concept of the pathway; it's parts and directions: Sensor----> afferent nerve--->(into CNS)---> interneuron----> (out of CNS)---->efferent neuron----> effector.
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What are reflexes?
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Reflexes are automatic, subconscious responses to changes (Stimuli) occuring both internally and externally.
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What do reflexes maintain?
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Reflexes maintain homeostasis (heart rate, b/p, breathing rate, and digestion) and automatic actions (swallowing, sneezing, coughing, and vomitting).
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What are some examples of reflexes?
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1.) Knee jerk: two neurons are/monosynaptic and involves a sensory neuron directly connecting to a motor neuron.
2.) withdrawal: three neurons are/polysynaptic; utilizes interneurons and is initiated by a painful stimuli.
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What is the spinal cord composed of?
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The Spinal cord is composed of 31 segments, each giving rise to a spinal nerve and serves as the center for spinal reflexes and the conduit for nerve impulses to and from the brain: 'two way communication'.
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Where does the spinal cord start and end?
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The spinal cord starts at the foramen magnum and ends at the 1st/2nd lumbar vertebrae at the conus medullaris.
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Where do nerve fibers extend from and what does this attach to?
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Nerve fibers extend down from where the cord ends, which is called filum terminale and this attaches to the coccyx.
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What is internal gray matter of the spinal cord?
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The internal gray matter is shaped like a butterfly and has posterior, anterior, and lateral horns. The gray matter is composed of interneurons, specifically in the anterior horns; it is also rich in blood vessels and contains neuroglial cells.
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What is the central canal?
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The central canal is continous with the ventricles of the brain and contains CSF.
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What is outside the gray matter?
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'Outside" the gray matter the spinal cord has white matter; it is divided by the gray matter into three regions on each side (anterior, lateral, and posterior columns, and each column consists of bundles of myelinated nerve tracts (axons).
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What does the peripheral nervous system include?
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The peripheral nervous system includes the cranial and spinal nerves.
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What are the somatic fibers responsible for?
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The somatic fibers are responsible for conscious activities in skin and muscle.
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What are automatic fibers responsible for?
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Automatic fibers are responsible for unconscious actions in the viscera.
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Where do the spinal nerves emerge from?
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Out of the 31 pairs of spinal nerves, each spinal nerve emerges from the cord by two short branches called roots.
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