Chp 13.pdf

Physiology: Chp 12 D & Chp 13 Autonomic & Somatic Motor Control Juan J. Bustamante, Ph.D. Assistant Professor Pharmaceutical Science Phone (361) 221-0643 Email: [email protected] Office: Room 223 © 2016 Pea...

Physiology: Chp 12 D & Chp 13 Autonomic & Somatic Motor Control Juan J. Bustamante, Ph.D. Assistant Professor Pharmaceutical Science Phone (361) 221-0643 Email: [email protected] Office: Room 223 © 2016 Pearson Education, Inc.  Chapter 13 Neural reflexes Autonomic reflexes Skeletal muscle reflexes The integrated control of body movement Control of movement in visceral muscles © 2016 Pearson Education, Inc.  Reflex tests help doctors recognize brain damages, spinal injuries and neuromuscular conditions. (https://absoluteinjury.com/understanding-the-reflex-test/ © 2016 Pearson Education, Inc. © 2016 Pearson Education, Inc. Figure 13.1a Neural Reflexes Somatic motor neurons control of skeletal muscles © 2016 Pearson Education, Inc. Figure 13.5 The patellar tendon (knee jerk) reflex Slide 2 The patellar tendon (knee jerk) reflex illustrates a monosynaptic stretch reflex and reciprocal inhibition of the antagonistic muscle (a polysynaptic reflex). Stimulus: Tap to tendon stretches muscle. © 2015 Pearson Education, Inc. Figure 13.5 The patellar tendon (knee jerk) reflex Slide 3 Receptor: Muscle spindle stretches and fires. Stimulus: Tap to tendon stretches muscle. © 2015 Pearson Education, Inc. Figure 13.5 The patellar tendon (knee jerk) reflex Slide 4 Afferent path: Action potential travels through sensory neuron. Receptor: Muscle spindle stretches and fires. Stimulus: Tap to tendon stretches muscle. © 2015 Pearson Education, Inc. Figure 13.5 The patellar tendon (knee jerk) reflex Slide 5 Afferent path: Action Integrating potential travels through center: sensory neuron. Sensory neuron Receptor: Muscle synapses in spindle stretches and fires. spinal cord. Stimulus: Tap to tendon stretches muscle. © 2015 Pearson Education, Inc. Figure 13.5 The patellar tendon (knee jerk) reflex Slide 6 Afferent path: Action Integrating potential travels through center: sensory neuron. Sensory neuron Receptor: Muscle synapses in spindle stretches and fires. spinal cord. Stimulus: Tap to tendon stretches muscle. Efferent path 1: onto Somatic motor neuron monosynaptic stretch reflex Efferent path 2: Interneuron inhibiting somatic motor neuron Reciprocal inhibition polysynaptic reflex Reciprocal inhibition: antagonistic muscles must relax as the prime mover muscles contract © 2015 Pearson Education, Inc. Figure 13.5 The patellar tendon (knee jerk) reflex Slide 7 Afferent path: Action Integrating potential travels through center: sensory neuron. Sensory neuron Receptor: Muscle synapses in spindle stretches and fires. spinal cord. Stimulus: Tap to tendon stretches muscle. Efferent path 1: onto Somatic motor neuron Effector 1: Quadriceps muscle Efferent path 2: Interneuron inhibiting somatic motor neuron Effector 2: Hamstring muscle © 2015 Pearson Education, Inc. Figure 13.5 The patellar tendon (knee jerk) reflex Slide 8 Afferent path: Action Integrating potential travels through center: sensory neuron. Sensory neuron Receptor: Muscle synapses in spindle stretches and fires. spinal cord. Stimulus: Tap to tendon stretches muscle. Efferent path 1: onto Somatic motor neuron Effector 1: Quadriceps muscle Efferent path 2: Interneuron inhibiting somatic motor neuron Response: Quadriceps contracts, swinging lower leg forward. Effector 2: Hamstring muscle Response: Hamstring stays relaxed, allowing extension of leg (reciprocal inhibition). © 2015 Pearson Education, Inc.  The crossed extensor reflex Slide 1 Figure 13.6 Spinal cord Gray matter Spinal cord White matter Sensory neuron Ascending pathways Painful stimulus activates to brain nociceptor. Primary sensory neuron enters spinal cord and diverges. One collateral activates ascending pathways for sensation (pain) and Nociceptor postural adjustment (shift in center of gravity). Alpha motor Withdrawal reflex pulls foot away neurons from painful stimulus. Painful stimulus Crossed extensor reflex supports body as weight shifts away from Extensors inhibited. painful stimulus. Extensors contract as Flexors contract, weight shifts to left leg. moving foot away from painful stimulus. Flexors inhibited. © 2015 Pearson Education, Inc. Figure 13.6 The crossed extensor reflex Slide 2 Spinal cord Sensory neuron Painful stimulus activates nociceptor. Nociceptor Painful stimulus © 2015 Pearson Education, Inc. Figure 13.6 The crossed extensor reflex Slide 3 Spinal cord Gray matter Spinal cord White matter Sensory neuron Painful stimulus activates nociceptor. Primary sensory neuron enters spinal cord and diverges. Nociceptor Painful stimulus © 2015 Pearson Education, Inc. Figure 13.6 The crossed extensor reflex Slide 4 Spinal cord Gray matter Spinal cord White matter Sensory neuron Ascending pathways Painful stimulus activates to brain nociceptor. Primary sensory neuron enters spinal cord and diverges. One collateral activates ascending pathways for sensation (pain) and Nociceptor postural adjustment (shift in center of gravity). Painful stimulus © 2015 Pearson Education, Inc. Figure 13.6 The crossed extensor reflex Slide 5 Spinal cord Gray matter Spinal cord White matter Sensory neuron Ascending pathways Painful stimulus activates to brain nociceptor. Primary sensory neuron enters spinal cord and diverges. One collateral activates ascending pathways for sensation (pain) and Nociceptor postural adjustment (shift in center of gravity). Alpha motor Withdrawal reflex pulls foot away neurons from painful stimulus. Painful stimulus Extensors inhibited. Flexors contract, moving foot away from painful stimulus. © 2015 Pearson Education, Inc. Figure 13.6 The crossed extensor reflex Slide 6 Spinal cord Gray matter Spinal cord White matter Sensory neuron Ascending pathways Painful stimulus activates to brain nociceptor. Primary sensory neuron enters spinal cord and diverges. One collateral activates ascending pathways for sensation (pain) and Nociceptor postural adjustment (shift in center of gravity). Alpha motor Withdrawal reflex pulls foot away neurons from painful stimulus. Painful stimulus Crossed extensor reflex supports body as weight shifts away from Extensors inhibited. painful stimulus. Extensors contract as Flexors contract, weight shifts to left leg. moving foot away from painful stimulus. Flexors inhibited. © 2015 Pearson Education, Inc.  Skeletal Muscle Reflexes Proprioceptors are located in skeletal muscle, joint capsules, and ligaments Input signals from proprioceptors go to the CNS through sensory neurons CNS integrates input signal Somatic motor neurons carry output signal Alpha motor neurons Effectors are contractile skeletal muscle fibers, or extrafusal muscle fibers © 2016 Pearson Education, Inc.  Skeletal Muscle Reflexes Proprioceptors Joint receptors In capsules and ligaments around joints Golgi tendon organ In skeletal muscles Muscle spindle In skeletal muscles © 2016 Pearson Education, Inc. Figure 13.3 The stretch reflex © 2016 Pearson Education, Inc.  The CNS Integrates Movement Integrated, coordinated responses require input from multiple regions of the brain Movement can be Reflex, least complex, integrated at the spinal cord or brain stem Voluntary, most complex, integrated in cerebral cortex Voluntary movements require coordination between the cerebral cortex, cerebellum, and basal ganglia. Travel from cortex to spinal cord through the corticospinal tract Rhythmic, intermediate complexity; integrated in spinal cord with higher center input required © 2016 Pearson Education, Inc.  Integration of muscle reflexes © 2016 Pearson Education, Inc.  Control of voluntary movements Slide 1 Figure 13.9 Sensory input Prefrontal cortex Motor cortex Sensory cortex Planning and Motor association decision-making areas Basal Coordination and timing: Thalamus ganglia cerebellar input Feedback Brain stem Cerebellum Execution: corticospinal tract to skeletal muscles Execution: extrapyramidal influence on posture, Spinal cord balance, and gait KEY Muscle Continuous feedback Input contraction Sensory Output and receptors Feedback movement © 2015 Pearson Education, Inc. © 2016 Pearson Education, Inc.