The Muscular System

General Muscle Functions

the body and its parts to move or to move thingsMuscular tissue enables the body and its parts to move or to move things the ability of muscle fibers to contractMovement caused by the ability of muscle fibers to contract elasticMuscle fibers are elastic –have memory by converting chemical energy into mechanical energy, which causes movementMuscle cells shorten by converting chemical energy into mechanical energy, which causes movement Poor ability to repair itselfPoor ability to repair itself

Types Three Types of Muscle Tissue Classified according to –Voluntary or Involuntary –Striated or non-striated –Appearance Continuous CylindersContinuous Cylinders BranchingBranching Smooth SheetsSmooth Sheets SkeletalSkeletal CardiacCardiac SmoothSmooth

A. Skeletal Basic MovementBasic Movement Threadlike / Cylindrical StriatedStriated –Microscopic Stripes Voluntary – You Control ContractionsVoluntary – You Control Contractions –Speed –Rate –Intensity Red Meat40% to 50% of body weight – Red Meat

B. Cardiac Branching cylinders that reconnect Controls Heart Rate – Heart Pumping / Squeezing InvoluntaryInvoluntary –Controlled by Brain / Hormones intercalated disksCharacterized by unique dark bands called intercalated disks –Interconnected nature of cardiac muscle cells allows heart to contract efficiently as a unit

C. Smooth or Visceral Smooth Sheet-like / Cells taperSmooth Sheet-like / Cells taper Found in walls of hollow organs (Visceral) –Digestive Tract –Blood Vessels –Bladder Lacks cross stripes or striations when seen under a microscope –Appears Smooth –Involuntary Moves substances through body –Controlled by brain / hormones / nerves