Frog Muscle Lab Report
Results A left gastrocnemius muscle of a frog (L=3.2cm in situ) was used in experiment 1 and 2, while a right gastrocnemius muscle of a frog (L=3.4cm in situ) was used in experiment 3. The sciatic nerve of the frog was placed over the stimulatory electrodes covered with a piece of a Kimwipe moistened with Ringer's solution. The relationship between muscle length, force production and velocity of contraction was studied.
Force transduced calibration
In order to get a more accurate data from force transducer, a calibration was made. A series of weight (10-60 grams) was suspended from the "notched" position and the hole position of the blade of a force transducer. Fig 1 shows a positive linear relationship between displacement and load in notch position, and it shows a more positive linear relationship (a steeper slope) between displacement and load in hole position.
Measurement of a single twitch
Fig 2 shows a single twitch of a frog gastrocnemius muscle after a stimulus at 1.0Hz frequency, 10ms duration, and 2.0V intensity. A twitch peak of this single twitch is measure as 58.72g.
Measurement of partial tetany and complete tetany …show more content…
A partial tetany can be observed when the muscle does not relax completely between stimuli, and a complete tetany can be observed when there is no relaxation between contractions and maximal tension is developed. Fig 3a shows a measurement of partial tetany. With increasing frequency of stimulation, there is less and less time for the muscle fiber to relax between stimuli. Fig 3b shows a measurement of complete tetany. With increasing frequency of stimulation, the contractions eventually fuse, and a smooth powerful tetanus is seen. The peak tetany amplitude is 149.79g, the time to achieve tetany is 0.56s, and the time for relaxation is
Force transduced calibration
In order to get a more accurate data from force transducer, a calibration was made. A series of weight (10-60 grams) was suspended from the "notched" position and the hole position of the blade of a force transducer. Fig 1 shows a positive linear relationship between displacement and load in notch position, and it shows a more positive linear relationship (a steeper slope) between displacement and load in hole position.
Measurement of a single twitch
Fig 2 shows a single twitch of a frog gastrocnemius muscle after a stimulus at 1.0Hz frequency, 10ms duration, and 2.0V intensity. A twitch peak of this single twitch is measure as 58.72g.
Measurement of partial tetany and complete tetany …show more content…
A partial tetany can be observed when the muscle does not relax completely between stimuli, and a complete tetany can be observed when there is no relaxation between contractions and maximal tension is developed. Fig 3a shows a measurement of partial tetany. With increasing frequency of stimulation, there is less and less time for the muscle fiber to relax between stimuli. Fig 3b shows a measurement of complete tetany. With increasing frequency of stimulation, the contractions eventually fuse, and a smooth powerful tetanus is seen. The peak tetany amplitude is 149.79g, the time to achieve tetany is 0.56s, and the time for relaxation is