Since the other answer got deleted, i'll just answer it for you.
a sinoatrial node is the main pacemaker that begins each heartbeat located in the junctions of superior vena cava and the right atrium. It signals from the node that spread through the atria and determines the heart rates.
Answer:The process of photosynthesis is energy-releasing because the process converts light energy into free energy that can be
used for cell functions.
Explanation:
Photosynthesis is a process used by green plants to convert light energy into chemical energy that is later released to fuel the organisms' activities. ... In these light-dependent reactions, some energy is used to release electrons from suitable substances, such as water, producing oxygen gas.
<span />An impulse moves from one neuron to another through the action of: neurotransmitters
