We get tired after exercise because our muscle fibers get tired very quickly. This is due to the major source of energy for the muscle tissue, called adenosine triphosphate, or ATP. As the muscles make use of this supply of energy, they get tired and fatigue.
Id say it would be all of the above. if you think about it our bodies mentally and physically need to rest so they can be "charged" and ready for theday. if you dont sleep you will be drowsy and not to be able to focus on any of the options
I'm not going to fully write out <span>3-4 paragraphs but I will give you some information to start out with :) I greatly enjoy doing research and writing about the things I have learned.
Arteries:
Arteries are </span>any of the muscular-walled tubes forming part of the circulation system by which blood (mainly that which has been oxygenated) is conveyed from the heart to all parts of the body. <span> Each artery is a muscular tube lined by smooth tissue and has three layers. These are the three layers and their purpose.
*The i</span>ntima-T<span>he inner layer lined by a smooth tissue called endothelium
</span>*The media- A<span> layer of muscle that lets arteries handle the high pressures from the heart
*</span>The adventitia-Connective tissue anchoring arteries to nearby tissues
Veins<span> are </span>blood vessels<span> that carry </span>blood<span> toward the </span>heart<span>. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the </span>pulmonary<span> and </span>umbilical veins<span>, both of which carry oxygenated blood to the heart. In contrast to veins, </span>arteries<span> carry blood away from the heart.
</span>Veins are classified in a number of ways, including superficial vs. deep, pulmonary vs. systemic, and large vs. small.
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*Superficial veins are those closer to the surface of the body, and have no corresponding arteries.
</span><span>*Deep veins are deeper in the body and have corresponding arteries.
</span><span>*Perforator veins drain from the superficial to the deep veins. These are usually referred to in the lower limbs and feet.
</span><span>*Communicating veins are veins that directly connect superficial veins to deep veins.
*P</span>ulmonary veins<span> are a set of veins that deliver oxygenated blood from the </span>lungs<span> to the heart.
*</span><span>Systemic veins drain the tissues of the body and deliver deoxygenated blood to the heart.
I hoped this helped and gave you some useful information. Good luck, I hope you do well on your assignment :) ~Sadie
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A it varies from state to state
