January 5, 2015 Journal: How do the skeletal and muscular systems interact?

Muscular System

The movement of the body both externally and internally

Muscle All the contractile tissue in our bodies Muscles contract, becoming short and thick, in response to a nerve impulse Muscles relax, becoming elongated, when the nerve impulse is removed

Muscle cells Elongated and resemble fibers in our clothing Bundle together to form muscular tissues

What are the three types of muscles?

Skeletal Muscle Overview Voluntary muscles (under conscious control) attached to the bones of the skeletal system Appear striped, so may also be called striated Control external movements such as walking or lifting weights

Smooth Muscle Overview Involuntary muscles (not under conscious control) that do not have a striated appearance Found within organs, blood vessels, and airways so can also be called visceral muscle Allows for the internal movement of food Allows for the movement of blood and air by changing the diameter of the passageways

Cardiac Muscle Overview Specialized muscle found only in the heart Involuntary muscle that is striated in appearance Makes up the walls of the heart and make it contract causing blood circulation

January 7, 2015 Journal: ◦ What are the differences between cardiac, skeletal, and smooth muscle?

How Skeletal Movement Happens

Contraction and Relaxation Contraction: shortening of the muscle fibers Relaxation: lengthening or relaxing of the muscle fibers Movement occurs when certain muscles contract while others relax

Agonists Also known as primary movers The muscle that causes the movement Ex: When touching your fingers to your shoulder, the biceps on top of your humerus are the agonists

Point of Origin The end of the muscle that is attached to the bone that is stationary or not moving Ex: When touching your fingers to your shoulder, the end of your biceps by your shoulder is the point of origin

Point of Insertion The end of the muscle that is attached to the moving bone Ex: When you are touching your fingers to your shoulder it is the end of the biceps near your elbow

Synergistic Muscles Muscles that assist the primary mover Ex: When touching your fingers to your shoulder, your wrist muscles and your finger muscles may also move

Antagonists Muscles that move in the opposite direction of the primary mover Ex: When touching your fingers to your shoulder, the triceps must relax while the biceps contract

Name the agonist, point of origin, point of insertion, synergistic muscles, and antagonist for the following examples: Straightening your leg when sitting in a chair Flexing your toes back towards your body