Kinesiology 2230A/B Lecture Notes - Glycolysis, Titin, Enzyme
Document Summary
Spinal cord injury: you lose all function below the injury. Sacral: lose all but some innervation to lower legs. Lumbar: lose some function in legs (may have some adduction of legs) The action potential moves down the cell (sarcolemma) membrane. Ap then passes through t tubules which are perpendicular to the myofibrils. This stimulates the release of calcium from the sarcoplasmic reticulum (where it is stored): this bathes the contractile proteins which gives a contraction of the filaments. (fence like structure) The sarcoplasmic reticulum functions to uptake calcium from the sarcoplasm and to release calcium into the sarcoplasm to initiate contraction and sequester it during relaxation. On both sides of a t-tubule are dilated end sacs of the sarcoplasmic reticulum called the terminal cisternae. A t-tubule, together with its two terminal cisternae, is called a muscle triad: terminal cisternae is where the calcium is stored.