Answer:
The slow arrival of contraction or the slow onset of contraction.
Explanation:
The T tubules function in the transformation of the action potential from the sarcolemma to the sarcopasm reticulum.
In the skeletal muscles, it is located at the junction of the A and I bands but in the cardiac muscles, it is located only at the z discs thus giving rise to to T tubules.
The cardiac muscles also do not possess as much calcium as the skeletal muscles thus, its calcium ion must come from outside producing the slow arrival of contraction or the slow onset of contraction.
Answer:
B. found in every living thing
Explanation:
Chordata because humans are vertebrates (humans have back bones)