LAB 10 REFLEX ACTION: REFLEX TIME

• Experiment 10

  Reflex Action: Reflex Time
• Materials and equipment

  • Tron stand
  • clamps
  • 0.05% HCL
  • 0.5% HCl soln.
  • 1% novocaine
  • 30% acetic acid soln.
  • 1% sodium bicarbonate soln.
  • 1% HCl soln.
• Reflex Time

  1. Single pith a frog, wait until there is recovery from spinal shock. And suspend it by a wire hook passed through the lower jaw.

  2. Dip the left toes in 0.05% HCl soln. for 1 min. Determine how reflex time.

  3. Bathe the left foot in 1% sodium bicarbonate soln., then bathe it in water. Let the frog rest for three minutes.

  4. Repeat procedure 2 using 0.5% HCl soln. Then repeat procedure 3.

  5. Repeat procedure 2 using 1% HCl soln. Then repeat procedure 3.
• Purposive Nature of Reflexes


  1. Moisten a small piece of filter paper with 30% acetic acid and place it on the ventral aspect of the thigh. Note the response of the animal.

  2. Remove the filter paper and rinse the thigh with tap water. Let the frog rest for five minutes.

  3. Repeat procedure 1 several times, each time changing the location of the filter paper.
• Effect of Anesthesia on Reflex Time


  1. Single pith another frog. Determine the reflex time with 1% HCl soln., using the procedure above.

  2. Dip the left foot in 1% novocaine. After two minutes, dry the foot with filter paper and take the reflex time.
• The Reflex Arc


  1. The moment the left foot in (C) becomes irritable once more, cut all the roots of the left sciatic nerve and test for the presence of a reflex action. Do the same on the right.

  2. Destroy the spinal cord and determine again the possibility of a reflex action.