SA Node<span> which is also known as the sinus node, is the natural pacemaker of
the heart. It controls the heart rate by generating electrical impulses
and then sending electrical signals through the heart muscle, causing
the heart to contract and pump blood throughout the body. </span>
The SA Node is located in the outer layer of the right atrium of the heart, near the superior vena cava. It is made up of a group of cells (myocytes) positioned on the
wall of the right atrium, at the center of the heart and near the
entrance of the superior vena cava. These cells contract at a rate of
about 70-80 times per minute, which make up the natural heart beat.
Answer:
it Changes according to the receptor.
Explanation:
Every cell has different receptors in the membrane, these receptors are specific, but different receptors can read one signal molecule, according to the receptor, this molecule can activate or inactivate different path ways.
Let me put it this way, if I give the same message to a botanist and a gardener they both are going to read it in different way even knowing it is the same.
the correct answer is carbohydrates because this fat can produce both short and fast energy.