The Muscular System

1. The Muscular System

2. or “Everything you ever wanted to know about Muscles, but were afraid to ask” !!!

3. Did you know that ? • more than 50% of body weight is muscle ! • And muscle is made up of proteins and water

5. The Muscular System • Muscles are responsible for all _______________ of the body • There are three basic types of muscle

6. Info About Muscles • Only body tissue able to ______________ • create movement by _______and ________joints • Body ________converters (many muscle cells contain many _____________)

7. 3 Types of Muscles

8. Skeletal Cardiac Smooth Three types of muscle

9. Classification of Muscle

10. Characteristics of Muscle • Skeletal and smooth muscle are elongated • Muscle cell = muscle fiber • Contraction of a muscle is due to movement of ____________________ (protein fibers) • All muscles share some terminology • Prefixes _____ and _______ refer to muscle • Prefix ________ refers to flesh

11. Shapes of Muscles • ______________- shoulder, neck • ______________- arms, legs • ____________- diaphragm, forehead • ____________- mouth, anus

12. Skeletal Muscle • Most are attached by ___________ to bones • Cells have more than one nucleus (multinucleated) • _____________- have stripes, banding • ____________- subject to conscious control • Tendons are mostly made of _______ fibers • Found in the limbs • Produce movement, maintain posture, generate heat, stabilize joints

13. Structure of skeletal muscle • Each cell (fiber) is long and cylindrical • Muscle fibers are multi-nucleated • Typically 50-60mm in diameter, and up to 10cm long • The contractile elements ofskeletal muscle cells aremyofibrils

14. Skeletal muscle - Summary • Voluntary movement of skeletal parts • Spans joints and attached to skeleton • Multi-nucleated, striated, cylindrical fibers

15. Smooth Muscle • _________________ • Spindle shaped • Single nucleus • _________________- no conscious control • Found mainly in the walls of hollow organs

16. Smooth muscle • Lines walls of _______ • Found in longitudinal or circular arrangement • Alternate contraction of circular & longitudinal muscle in the intestine leads to ____________

17. Structure of smooth muscle • Spindle shaped uni-nucleated cells • Striations not observed • ______and ________ filaments are present ( protein fibers)

18. Smooth muscle - Summary • Found in walls of hollow internal organs • Involuntary movement of internal organs • Elongated, spindle shaped fiber with single nucleus

19. Cardiac Muscle • _____________ • ______________ cells • Involuntary • Found only in the ___________ • Usually has a single nucleus, but can have more than one

20. Cardiac muscle • Main muscle of heart • Pumping mass of heart • Critical in humans • Heart muscle cells behave as one unit • Heart always contracts to it’s full extent

21. Structure of cardiac muscle • Cardiac muscle cells (_______) are short, branched and interconnected • Cells are striated & usually have 1 nucleus • Adjacent cardiac cells are joined via electrical synapses (gap junctions) • These gap junctionsappear as dark lines and are called intercalated discs

22. Cardiac muscle - Summary • Found in the heart • Involuntary rhythmic contraction • Branched, striated fiber with single nucleus and intercalated discs

23. Type of muscle Nervouscontrol Type of control Example Controlled by CNS Voluntary Lifting a glass Regulated by ANS Involuntary Heart beating Controlled by ANS Involuntary Peristalsis Muscle Control _______ Skeletal _______ ________

24. Types of Responses • _________- • A single brief contraction • Not a normal muscle function • _____________ • One contraction immediately followed by another • Muscle never completely returns to a relaxed state • Effects are compounded

25. Where Does the Energy Come From? • Energy is stored in the muscles in the form of ________ • ATP comes from the breakdown of glucose during ___________________ • This all happens in the ____________ of the cell • When a muscle is ___________(tired) it is unable to contract because of lack of _________

26. Exercise and Muscles • __________- muscles shorten and movement occurs ( most normal exercise) • ___________- tension in muscles increases, no movement occurs (pushing one hand against the other)

27. How are Muscles Attached to Bone? • ___________-attachment of a muscle that remains relatively fixed during muscular contraction • ______________-the movable attachment of a muscle as opposed to its origin • Muscles are always attached to at least 2 points • Movement (Action) is attained due to a muscle moving an attached bone

28. Insertion Origin Muscle Attachments