Download Chapters 11c , 13 Integration and Reflexes

Chapters 11c , 13 Integration and Reflexes
neural integration
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integration
connects sensory neurons to motor neurons
integration centers
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sensory input
brain, spinal cord
motor response
appropriate reaction to change in conditions
simplest
=
1 synapse + 2 neurons
neurons connect to neurons
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neuronal pools
neurons with similar function
circuits
pattern of synaptic networks
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diverging
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converging
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reverberating
amplifying
• eg. 1 sensory neuron to several brain areas
• eg. CNS motor neuron to 1000’s skeletal muscles
concentrates input
• eg. several sensory neurons to 1 brain area
• eg. different stimuli affect 1 motor neuron
stimulates itself
• eg. rhythmic output
• eg. memory
breathing
neural processing
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serial processing
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sensory neuron connects to one interneuron or
motor neuron
stimulus always causes same motor response
parallel processing
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sensory neuron connects to several interneurons
stimulus causes several responses
many stimuli involve both
reflexes
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direct connection of stimulus to response
somatic reflex
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sensory
muscle, joint, skin
motor
skeletal muscle
visceral reflex
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sensory
organs
motor
smooth, cardiac muscle
spinal reflex
function w/o brain centers
learned reflex
w/ higher brain centers
endocrine reflex
endocrine reflex path
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control reflex path from stimulus to response
stimulus
=
change in condition
afferent signal
stimulus - change in condition
receptor
endocrine gland
integration
endocrine gland
efferent signal
hormone
effector
organ , tissue response
reflex arc
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5 components :
receptor
sensation specific
sensory neuron
integration center
synapse or interneuron
motor neuron
effector
muscle, organ
withdrawal (flexor) reflex
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pain (danger)  protective muscles flex
receptors
painful stimulus
sensory neuron
integration
interneuron
motor neuron
effector
eg.
flexor muscles
withdraw from stimulus
heat, pain , touch, surprise, sound, light
crossed extensor reflex
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contralateral extension
receptors
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reciprocal activation
painful stimulus
sensory neuron
integration
interneuron
motor neuron
effector
contralateral extensors
balance
coordination
muscle spindle
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muscle tissue
maintains “normal” length
posture, balance
prevent injury to muscle
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intrafusal fibers
noncontractile muscle fibers
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sensory neurons
stim by stretch
motor (gamma)
adjust length - contract
extrafusal fibers
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motor (alpha)
skeletal muscle fibers
contracts muscle
stretch reflex
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stretch muscle  muscle contracts
receptors
muscle spindle stretched
sensory neuron
integration
synapse
motor neuron
to muscle
effector
muscle (contracts)
serial processing
reciprocal inhibition
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stretch muscle  antagonists relax
receptors
muscle spindle stretched
sensory neuron
integration
interneuron
motor neuron
to antagonists
effector
muscles relax
parallel processing
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also: sensory to brain
DTR
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deep tendon reflexes
increase
UMN lesion
decrease
LMN lesion
Golgi tendon reflex
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stretch tendon  muscle relaxes
prevents injury to tendon
receptors
tendon stretched
sensory neuro
integration
interneuron
motor neuron
to muscle, synergists
effector
relax muscle , synergists
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parallel
contract antagonists
visceral reflex
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receptors
visceral or somatic stimuli
sensory neuron
integration
interneurons
motor neuron
ANS
effector
organs, blood vessels
eg.
cough , sneeze
swallow
BP
HR
CO2
pupils
brain , spinal cord
CNS and visceral reflex – eg. BP
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receptor
blood vessel
sensory neuron
to spinal cord
integration
neuron up spinal cord
neuron circuit in brain
neuron down spinal cord
2 motor neurons
from spinal cord
effector
smooth muscle – blood vessel
cardiac muscle
CNS as integration center
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connect “appropriate” motor responses to stimuli
increased parallel pathways
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to/from several brain areas
to several effectors
brain
spinal cord
skeletal muscles
several organs