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

3. How are Muscles Attached to Bone? skeletal muscles are attached to bones on each end by tendons. The origin is the fixed attachment, while the insertion moves with contraction Muscles are always attached to at least 2 points

4. The Muscular System Muscles are responsible for all movement of the body There are three basic types of muscle Skeletal Cardiac Smooth

5. 3 Types of Muscles

6. Three types of muscle SkeletalCardiacSmooth

7. Classification of Muscle Skeletal- found in limbs Cardiac- found in heart Smooth- Found in viscera Striated, multi- nucleated Striated, 1 nucleus Not striated, 1 nucleus voluntaryinvoluntary

8. Characteristics of Muscle Skeletal and smooth muscle are elongated Muscle cell = muscle fiber Contraction of a muscle is due to movement of microfilaments (protein fibers)

9. Shapes of Muscles Triangular- shoulder, neck Spindle- arms, legs Flat- diaphragm, forehead Circular- mouth, anus

10. The Skeletal Muscles There are about 650 muscles in the human body. They enable us to move, maintain posture and generate heat and stabilize joints.

11. Skeletal Muscle Most are attached by tendons to bones Cells have more than one nucleus (multinucleated) Striated- have stripes, banding Voluntary- subject to conscious control Tendons are mostly made of collagen fibers Found in the limbs

12. Structure of skeletal muscle Each cell (fibre) is long and cylindrical Muscle fibres are multi-nucleated Typically 50-60mm in diameter, and up to 10cm long The muscle fibers are bound together with delicate areolar tissue, which is condensed on the surface to form a fibrous envelope, the epimysium

13. pennate muscles Muscles whose fibers run obliquely to the line of pull are referred to as pennate muscles(they resemble a feather)

14. pennate muscles uni pennate (e.g., extensor digitorum longus). bipennate (e.g., rectus femoris). multipennate (e.g., acromial fibers of the deltoid)

15. Skeletal muscle - Summary Voluntary movement of skeletal parts Found in limbs Multi-nucleated, striated, cylindrical fibres

16. Smooth Muscle Smooth muscle consists of long, spindle-shaped cells closely arranged in bundles or sheets. No striations Spindle shaped Single nucleus Involuntary- no conscious control Found mainly in the walls of hollow organs

17. Smooth muscle Lines walls of viscera Found in longitudinal or circular arrangement Alternate contraction of circular & longitudinal muscle in the intestine leads to peristalsis

18. Structure of smooth muscle Spindle shaped uni-nucleated cells Striations not observed Actin and myosin filaments are present( protein fibers)

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

20. Cardiac Muscle Cardiac muscle consists of striated muscle fibers that branch and unite with each other Striations Branching cells Involuntary Found only in the heart Usually has a single nucleus, but can have more than one

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

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

23. Muscle Control Type of muscle Nervous control Type of control Example Skeletal Controlled by CNS Voluntary Lifting a glass Cardiac Regulated by ANS Involuntary Heart beating Smooth Controlled by ANS Involuntary Peristalsis

24. Where Does the Energy Come From? Energy is stored in the muscles in the form of ATP ATP comes from the breakdown of glucose during Cellular Respiration This all happens in the Mitochondria of the cell

25. Muscle Attachments Origin Insertion

26. Flexion Types of Musculo-Skeletal Movement

27. Extension

28. Hyperextension

29. Abduction, Adduction & Circumduction

30. Rotation

31. More Types of Movement…… Inversion- turn sole of foot medially Eversion- turn sole of foot laterally Pronation- palm facing down Supination- palm facing up Opposition- thumb touches tips of fingers on the same hand