VPB 121: Veterinary Physiology - II (2+1)

TETANUS-PROCEDURE

• Arrange the apparatus as for recording the single muscle twitch.
• Dissect out a frog and isolate the gastrocnemius muscle and Sciatic nerve complex.
• Attach the tendon of the muscle to the lever at such a distance to record contraction of about 1 inch height.
• With the help of clutch and gear set the speed of the drum at slow. Substitute the spring key with the adjustable vibrating reed.
• Apply the point of the lever to the drum surface and draw the base line about 1” from the lower edge of the drum. Determine threshold stimulus.
• Apply few stimuli of the vibrating reed by suitably changing the stimuli rate of 5,7,10,15 and 20 per second and take separate recording of contraction for each stimulation rate by manipulating the short circuiting key.
• Replace the adjustable vibrating reed with Neef’s ham­mer in the primary circuit.
• Record the contraction of the muscle at a rate of about 100 stimuli per second.