The muscular system

functionfunction

• Supports the Supports the skeletonskeleton

• Aids inAids in movementmovement

• Controls vital Controls vital processes processes such as such as breathing and breathing and heartbeatheartbeat

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3 Different Muscle Types3 Different Muscle Types

• Skeletal MuscleSkeletal Muscle– Attaches to and moves bonesAttaches to and moves bones– Striated (striped)Striated (striped) – –

alternating light and dark bandsalternating light and dark bands– Multiple nuclei in each cellMultiple nuclei in each cell– VoluntaryVoluntary-under brain’s -under brain’s

conscious controlconscious control•Example: bicepsExample: biceps

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• Smooth muscleSmooth muscle

– Spindle-shaped cellsSpindle-shaped cells– One nucleus/cellOne nucleus/cell– No striationsNo striations– Controls breathing & digestionControls breathing & digestion

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• Cardiac muscleCardiac muscle

– StriatedStriated– Cells smaller than striated muscleCells smaller than striated muscle– 1 or 2 nuclei/cell1 or 2 nuclei/cell– InvoluntaryInvoluntary– Found only in theFound only in the heart heart

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Muscle FatigueMuscle Fatigue

• If oxygen is not available muscle If oxygen is not available muscle fatigue will set in . Cells will start fatigue will set in . Cells will start making energy by making energy by Anaerobic Anaerobic Respiration without oxygen.Respiration without oxygen.

• Lactic AcidLactic Acid accumulates in the accumulates in the skeletal muscles and causes a skeletal muscles and causes a burning pain in the muscles. burning pain in the muscles.

• Rest restores the oxygen Rest restores the oxygen

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Muscle functionMuscle function

• Voluntary muscleVoluntary muscle– Muscles that contract (move) only Muscles that contract (move) only

when you want them towhen you want them to– Examples: skeletal- biceps, Examples: skeletal- biceps,

abdominalsabdominals

• Involuntary muscleInvoluntary muscle– Muscles contract (move) on their ownMuscles contract (move) on their own– Examples: cardiac, stomach, etcExamples: cardiac, stomach, etc

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What connects our bones What connects our bones and our muscles???and our muscles???

• TendonsTendons– Connects skeletal muscle to bonesConnects skeletal muscle to bones– Ex. Achilles Tendon – connects Ex. Achilles Tendon – connects

gastrocnemius (calf) to heelgastrocnemius (calf) to heel bonebone

• LigamentsLigaments– Connects bone to boneConnects bone to bone– Ex. ACL – Anterior Cruciate LigamentEx. ACL – Anterior Cruciate Ligament

connects femur to fibulaconnects femur to fibula

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Malfunctions:Malfunctions:

• StrainStrain– Overstretching or tearing the Overstretching or tearing the muscle or muscle or

tendon tendon (can be caused by improper lifting)(can be caused by improper lifting)• SprainSprain

– Stretch or tear of Stretch or tear of lligamentigament (at the joint) (at the joint) resulting from sudden movement resulting from sudden movement (ankle,wrists)(ankle,wrists)

• ““Pulled hamstringPulled hamstring””– Tear in a hamstring muscleTear in a hamstring muscle

• Shin splintShin splint– An inflammatory condition of the front part of An inflammatory condition of the front part of

the tibiathe tibia

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MusclesMuscles

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 –Gluteus Maximus s9