Doctor And Life Saving Advice » upper arm http://healdoctor.com A Skills To Saving Your Life Wed, 31 Aug 2011 14:44:52 +0000 en hourly 1 Muscles Power http://healdoctor.com/vitamin-and-supplement/muscle-power/ http://healdoctor.com/vitamin-and-supplement/muscle-power/#comments Fri, 18 Dec 2009 09:30:49 +0000 Health Doctor http://healdoctor.com/?p=18 There are about 640 skeletal muscles in the body, forming 19477up to half of the body’s weight. Muscles cover the framework of the skeleton Skeletal muscles to give the body its shape. link two bones and pass across the joint between them. Each muscle is made up of muscle fibres that can be up to 30 cm 12 in) long but are thinner than a hair. There are three different types of muscle:

  • Skeletal muscles - The bulk of the body’s muscles are skeletal muscles, which move the body. Skeletal muscles are voluntary muscles – they do not contract on their own. In response to a nerve impulse from-the brain, the muscle contracts, pulling on the bone and moving it. Muscles can only pull and never push so they work in pairs. When the biceps contracts it pulls the firearm towards the upper arm, bending the arm at the elbow. The triceps on the opposite side of the upper arm relaxes, allowing this to happen. When the triceps contracts, the biceps relaxes and the movement is reversed.
  • Smooth muscles – Situated in the walls of the body’s hollow organs, such as the digestive tract, they perform automatic tasks such as propelling food along.
  • Cardiac muscle – This forms the non­stop pump that is the heart.
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