muscular system by: emily brosten stephanie elhard james valley vocational technical center
TRANSCRIPT
Introduction
• 1. 600 muscles in the body
• 2. Muscles are ~ made of bundles of muscle fibers which are held together by connective tissue.
• Voluntary ~ you can willfully control muscles
*facial expressions, chewing, swallowing, and movement of the head
• Involuntary ~ function without the person thinking about contracting the muscles. *digestive system, heart muscles, and blood vessels**Some muscles are both voluntary and involuntary ~ example eye blinking
• 1. Cardiac muscles ~ cells are packed so closely together its hard to tell one cell from another. ~forms walls of the heart ~contact to circulate blood ~involuntary
• 2. Visceral/Smooth muscles~found in internal organs of the body
*digestive, respiratory system, blood vessels, and eyes. ~muscles contract to cause movement in these areas ~involuntary function without the person thinking about contracting the muscle
• 1. Attaches to bones to provide voluntary movement.
• 2. During contractions provide heat and energy.
• 1.Tendon ~ strong, tough connective tissue cord, connect muscle to bone *Achilles Tendon (attaches to calf muscle and heel bone) *lumbodorsal fascia (surrounds the deep muscles of the back and trunk)
• 2. Fascia ~ tough, sheet-like membrane that covers and protects tissue*lumbodorsal fascia (surrounds the deep muscles of the back and trunk)
• 3.Origin ~ When a muscle attaches to the bone, the end doesn’t move.-usually attaches closer to the trunk of the body-where the muscle begins
1. Contractability ~ ability to shorten and thicken (when muscles work they contract that is they get shorter and thicker)
• 2. Extensibility ~ ability to stretch (when muscle is relaxed it becomes longer and thinner) *some muscles work while others relax *
• 3.Elasticity ~ ability to return to original length
• 4. Irritability ~ability to respond to stimulus
• 5. Tone ~ slight tension in the muscles at all times, even at rest
• 1. Adduction ~ moving a body part toward the midline
• 2. Abduction ~ moving a body part away from the midline
• 8. Depressors: lower a part of the body
• 9. Supination: the act of rotating the arm so the palm of the hand is upward.
Terminology
• Muscle tone: muscles that are partially contracted at all times, even when they may not be in use.
• Contracture: severe tightening of a flexor muscle that results in bending of a joint.
• Myology: my/o = muscles» ology = study of
– the study of muscles