The muscular system

function Supports the skeleton Aids in movement Controls vital processes such as breathing and heartbeat

3 Different Muscle Types Skeletal Muscle Attaches to and moves bones Striated (striped) – alternating light and dark bands Multiple nuclei in each cell Voluntary-under brain’s conscious control Example: biceps

Smooth muscle Spindle-shaped cells One nucleus/cell No striations Controls breathing & digestion

Cardiac muscle Striated Cells smaller than striated muscle 1 or 2 nuclei/cell Involuntary Found only in the heart

Muscle Fatigue If oxygen is not available muscle fatigue will set in . Cells will start making energy by Anaerobic Respiration without oxygen. Lactic Acid accumulates in the skeletal muscles and causes a burning pain in the muscles. Rest restores the oxygen

Muscle function Voluntary muscle Muscles that contract (move) only when you want them to Examples: skeletal- biceps, abdominals Involuntary muscle Muscles contract (move) on their own Examples: cardiac, stomach, etc

What connects our bones and our muscles??? Tendons Connects skeletal muscle to bones Ex. Achilles Tendon – connects gastrocnemius (calf) to heel bone Ligaments Connects bone to bone Ex. ACL – Anterior Cruciate Ligament connects femur to fibula

Malfunctions: Strain Overstretching or tearing the muscle or tendon (can be caused by improper lifting) Sprain Stretch or tear of ligament (at the joint) resulting from sudden movement (ankle,wrists) “Pulled hamstring” Tear in a hamstring muscle

Muscles There are about 650-800 muscles in your body with some conflicting opinions because what experts consider a muscle. Smallest muscle in the ear- stapedius Largest muscle –Gludeus Maximus