Question

7. You place your foot in the bathtub and determine the water is too hot. You pull your foot out of the bath. Based on what you learned in our sensory and motor lectures draw the neurons involved in this pathway. Things to include in your drawing A. The neurons involved in the sensory pathway and the locations where they synapse Thokarbow how many you should have for the sensory pawn B. The cortical areas of the brain involved. C The neurons involved in the motor pathway and the location where they synapse Think about how many you should have for the motor pathway sensory path won a perictal TO Tera Corter - elfoot! morco 3 new cons 8. Label the following on your drawing above: A. Who is the receptor and effector in your pathway? B. Receptor level - primary neuron C. Circuit level - secondary neuron D. Perception level - tertiary neuron E. Which neuron would be damaged in flaccid paralysis? F. Which neuron would be damaged in spastic paralysis? G. Nonsteroidal anti-inflammatory drugs such as ibuprofen inhibit the COX enzyme that is responsible for the synthesis of prostaglandins. Where in your pathway would NSAIDs work? H. Where in your pathway would an opiate such as morphine target?

Answer 1

Dendrites Sensory neuron (receptor cell) Action potential -Receptor potential Synaptic potential Muscle Motor neuron (effector cell) Spina cord Interneuron Action potential

Right side of brain Left side of brain - Interneuron Sensory pathway reaches the cerebral cortex for conscious perception Cerebral cortex An upper motor neuron from the cortex executes a motor command Thalamus Sensory pathway continues with second neuron projecting to the thalamus Upper motor neuron Interneuron Sensory axon enters the spinal cord and synapses with brain Spinal cord 2 Action potential in sensory axon Sensory neuron Sensory endings in skin Lower motor neuron The upper motor neuron contacts a lower motor neuron in the spinal cord Neuromuscular junction (8) The lower motor neuron causes contraction of the target skeletal muscle

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Somati matic sensory cortex Spinothalamic Tract Cerebrum Tertiary neuron Thalamus -Midbrain • Primary Secondary neuron Pons • Secondary Dorsal root ganglion Medulla oblongata Primary neuron cell body • Tertiary Primary neuron Spinothalamic tract of anterolateral system Spinal cord Free nerve endings Interneuron Gray commissure White commissure

• primary sensory areas are the primary cortical regions of the five sensory systems in the brain (taste, olfaction, touch, hearing and vision). Except for the olfactory system, they receive sensory information from thalamic nerve projections.
• Flaccid paralysis can be associated with a lower motor neuron lesion. This is in contrast to an upper motor neuron lesion, which often presents with spasticity, although early on this may present with flaccid paralysis.
• · It is the severing of upper motor neurons (the pyramidal tract, starting from the precentral gyrus and ending at the anterior horn in de medulla spinalis) that causes spastic paralysis. This is mostly due to hemorrhage or infarction, but other causes such as trauma
• damage can all lead to increase sensory neuron firing
  
  Aspirin works at the level of the sensory neuron
  --by decreasing PG synthesis, it reduces the sensory neuron (nociceptor) firing
  
  • NSAIDS work at the level of the signal on the neuron that receives the pain A major central target of NSAIDs is the descending pain control system
• Mechanism for pain inhibition
  reduction of inflammation
  inhibition of pain stimuli in neurons (i.e. PGs which stimulate neurons)
• Morphine works by affecting the receptors of the nervous system and results in sedation and pain relief.