I need a response for each person with citation/source olanna 1. ATP is a high energy compound. It is required in many processes occurring in the human body. Muscle contraction and relaxation also requires ATP. If there is no ATP to utilize the muscle contraction or relaxation procedure stops and the muscle stays in that position only. 2.Contraction of one sternocleidomastoid turns the chin to the opposite side and also tilts the head towards the shoulder of the same side. When both sternocleidomastoids contract, they draw the head forward. All these motions will be affected if we lack sternocleidomastoid muscle. 3 Cold causes vasoconstriction and heat causes vasodilation. jada Adenosine Triphosphate is known as ATP, ATP is an energy carrying molecule that is founded in all cells of living things. ATP is an energy provider and is used for muscles to function. If there is no ATP, this can cause muscles to stiffen up or even go into rigor mortis due to the lack of energy.Sternocleidomastoids is responsible for the movement of your heads rotation. If you lacked a SCM, you could only be able to turn it partially or maybe not at all. Ultimately, it would depend of the extent of the injury, cold compressions reduces blood flow by reducing swelling and constricts the blood flow to the area known as vasoconstriction whereas heat to the ankle would dilate and help ease any stiffness this is known as vasodilation.