This substance is released by the nervous system and excites ...

[cookcarl]

This substance is released by the nervous system and excites muscle cells (resulting in muscle contraction).
 
  A) actin
   B) myosin
   C) ATP
   D) calcium
   E) acetylcholine

Question 2

The specialized sites that are contacts between cardiac muscle cells are called what?
 
  A) Cardiac cellular gaps B) Intercalated discs
  C) Intercardiac synapses D) Cardiac potential sites

[k2629]

Answer to Question 1

E

Answer to Question 2

B