Warm
Ringer solution:
The latent
period, contraction period and relaxation period decreases. The height of
contraction increases.
Cold
Ringer solution:
The latent
period, contraction period and relaxation period increases. The height of
contraction decreases.
Q.1 What is the physiological basis of changes noticed in
SMC due to an increase in muscle temperature?
- Increase in temperature increases the excitability and hastens various metabolic processes in the muscle. It also decreases the viscosity. The total twitch duration decreases, with all the three periods reduced.
- Very High temperature, (45 to 50°C and above) causes coagulation of muscle proteins, the muscle shortens, and goes into an irreversible state called “heat rigor’.
Q.2 What is rigor mortis?
- Rigor mortis is shortening and rigidity of muscles, occurs some hours after death. The rigidity is due to loss of all the ATP which is required for detachment of cross-bridges which are fixed to actin filaments in an abnormal and resistant manner.
- The appearance and disappearance of rigidity helps in identifying the time of death.