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50 Cards in this Set
- Front
- Back
What are the two main types of reflexes?
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Learned (acquired) reflexes and inborn (intrinsic) reflexes
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What are acquired reflexes?
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They are complex reflexes that result from practice or repetition
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What are intrinsic reflexes?
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They are simple reflexes that are rapid, predictable motor responses to a stimulus
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Are intrinsic reflexes involuntary or voluntary?
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Involuntary (even if reflex involves voluntary skeletal muscles)
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What are the five steps to the reflex arc?
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1. Sensory receptor
2. Sensory neuron caries afferent input to the CNS 3. Integration center 4. motor neuron carries efferent output from CNS to effectors 5. Effector |
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Most sensory neurons are unipolar or multipolar?
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unipolar!
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Motor and association neurons are unipolar or multipolar?
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Multipolar!
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What are the two types of reflexes, scientifically?
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Autonomic reflexes and Somatic reflexes
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What are autonomic reflexes?
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Autonomic reflexes are involuntary that involve smooth muscle, cardiac muscle and glands
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What are some examples of autonomic reflexes?
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Pupils dilating, salivate when hungry, etc
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What are somatic reflexes?
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Somatic reflexes are involuntary reflexes that involve skeletal muscle
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What are 3 important facts about spinal somatic reflexes?
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1. Integration occurs in the spinal cord
2. Do not require input from the brain, occur even when the brain is damaged 3. brain usually dampens the reflex |
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TRUE OR FALSE: Somatic reflexes are involuntary even though they involve voluntary skeletal muscles.
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True
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What are stretch reflexes?
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Stretch reflexes are the simplest somatic spinal reflex
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What is the stimulus for stretch reflexes?
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A stretch in a skeletal muscle
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What are the responses to stretch reflexes?
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1. Reflex contraction of stretched muscle
2. Reflex relaxation of opposing muscle |
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Skeletal muscles often work in what kind of pairs?
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Opposing!
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If both opposing muscles contract at the same time, what occurs?
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No movement
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During the stretch reflex, one muscle ______ while the opposing muscle ______.
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Contracts. Relaxes
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What is the purpose of the stretch reflex?
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To maintain muscle tone in large postural muscles
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What are the sensory receptors in muscles?
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muscle spindles
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What are muscle spindles?
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Muscle spindles are proprioceptors which give you your "body sense"
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What do muscle spindles detect?
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They detect changes in muscle length
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When a muscle is unstretched, APs are generated at what kind of rate?
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Constant rate
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When a muscle is stretched, APs are generated at what kind of rate?
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Increasing rate
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A muscle responds to stretch by doing what?
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Contracting
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When only motor neurons are activated and extrafusal muscle fibers contract, the muscle spindle becomes what? What happens to APs?
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Slack and no APs are fired
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When both extrafusal and intrafusal muscle fibers contract, muscle spindle tension is what?
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maintained!
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What activates the muscle spindle?
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A stretch
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A stretch excites sensory neurons that synapse directly with what?
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Motor neurons in the spinal cord
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What are the sensory receptors in muscles?
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muscle spindles
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What are muscle spindles?
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Muscle spindles are proprioceptors which give you your "body sense"
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What do muscle spindles detect?
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They detect changes in muscle length
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When a muscle is unstretched, APs are generated at what kind of rate?
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Constant rate
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When a muscle is stretched, APs are generated at what kind of rate?
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Increasing rate
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A muscle responds to stretch by doing what?
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Contracting
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When only motor neurons are activated and extrafusal muscle fibers contract, the muscle spindle becomes what? What happens to APs?
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Slack and no APs are fired
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When both extrafusal and intrafusal muscle fibers contract, muscle spindle tension is what?
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maintained!
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What activates the muscle spindle?
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A stretch
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A stretch excites sensory neurons that synapse directly with what?
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Motor neurons in the spinal cord
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Motor neurons cause stretched muscles to what?
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contract
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Which reflexes are the only reflexes that are monosynaptic?
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Stretch reflexes!
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What is an example of a monosynaptic stretch reflex?
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Patellar (knee-jerk) reflex
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During the patellar reflex, which muscle is stretching and contracting?
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Quadriceps!
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What is reciprocal inhibition?
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Sensory neurons excite interneurons that then inhibit motor neurons to opposing muscles
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Is reciprocal inhibition monosynaptic or polysynaptic?
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Polysynaptic
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If motor neurons are firing, muscles are always what?
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Contracting
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Which neurons fire APs while the patellar reflex is activated?
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Sensory neuron, motor neuron to quadriceps, and interneurons
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Sensory neuron causes EPSPs or IPSPs in the motor neuron to quadriceps and in the interneuron?
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EPSPs!
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Interneuron causes EPSPs or IPSPs in motor neuron to the hamstrings?
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IPSPs!
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