50 points (all of my points) and brainiest to the best ! you will write about muscles in a 250-word essay that includes an introduction, body, and conclusion. your essay should be in your own words, and should contain original content. in order to avoid plagiarism, be sure to cite your sources. conduct research using at least two sources to locate additional information about muscles. some key words for your search might include the following: three different types of muscles skeletal muscle striated muscle smooth muscle cardiac muscle muscle fibers slow-twitch muscle fibers fast-twitch muscle fibers muscle contractions concentric contraction eccentric contraction isometric contraction keep the following questions in mind while conducting your research: what are muscles? what are the functions of muscles? why are they so important within the human body? how many muscles are found within the human body? what are three different types of muscles? what are the two basic types of muscle fibers? what are different types of muscle contractions?

Muscles in the body us with a lot of things for example, if i wanted to lift a heavy box and had no muscle i would just collapse where i was because of the fact muscles hold us together. overall they are 650 muscle in the human body, all of them have different purposes and ways to keep us together. there are three types of muscle in the body skeletal, smooth, and cardiac muscle. skeletal muscle are attached to the bone and with movement. smooth muscle, this is found in the wall of our organs, such as our stomach, this muscle with movement   as well, without this muscle, we would only be allowed to eat small amounts. the cardiac muscle is the heart muscle and probably the most important one. these are only found in the walls of the heart and the heart pump blood to the other parts of your body. we have two different types of muscle fibers, slow twitch and fast twitch. slow twitch muscles enable long-endurance feats such as distance running. fast twitch fatigue faster but are used in powerful bursts of movements like sprinting. there are three different types of muscle contractions concentric, eccentric, isometric. concentric contraction causes muscles to shorten, thereby generating force.   eccentric contractions cause muscles to elongate in response to a greater opposing force. isometric contractions generate force without changing the length of the muscle.: //athleticquickness.com/muscle-contraction-types-part-1/

People who utilizes the progression principle will ensure their exercise program increases in frequency, intensity, time, and type. the changes need to happen gradually in order to ensure they make gains in their fitness program. a person who doesn't utilize the progression principle can still gain health benefits from exercising, but will not continue to improve in cardiovascular fitness.

1. the answer is a parasite