Lab: Muscle Physiology

Laboratory – Muscle Physiology A. MUSCLE TONUS
Observations, Report and Conclusion: A. Define muscle tonus and give its importance * Muscle tonus refers to a state of slight muscular contraction maintained by synchronous impulses of low frequency, discharged by the spinal motor neurons. * Reflex in nature. * Muscle tonus is a small amount of tension in the muscle due to weak, involuntary contractions of its motor units. Muscle tonus is important in a sense that it governs the posture of an individual, enabling him to maintain body balance, to facilitate as well as coordinate body movements, whether simple or complex. B. Describe Spinal Shock, its duration according to species * Spinal shock is attributed to the
The higher the position of the animal in the phylogenetic scale or the higher the degree of development of the animal, the more profound is the shock and the slower is the recovery. C. What is observed when the roots of the sciatic nerve are cut * As we cut the root of the right sciatic nerve of the frog in the experiment, the right lower leg of the frog becomes limp. The right gastrocnemius muscle lost its firmness and becomes flabby while I have observed as we compared the tonicity of the muscles with the left gastrocnemius muscle (with the root of left sciatic nerve is still intact) it is different. The left gastrocnemius muscle remains firm with the sciatic nerve connected. This observation is supported with the fact that “afferent and efferent connections of the right gastrocnemius muscle with the spinal cord has been
In this junction, nerve attaches to the muscle, the impulses causes stimulation to trigger the release of acetylcholine which is combined in proteins for activation. The active form of acetylcholine causes an increase in the permeability of the membrane to sodium ions which causes depolarization due to the threshold induced by the impulses that were stimulated. Depolarization of muscle proceeds to its entire length and is followed by muscular contraction. Thus, the impulse generated in the nerve is transmitted to the