Survey of Anatomy and Physiology Chap 7


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  • Survey of Anatomy and Physiology Chap 7

    1. 1. 7 The Muscular System: Movement for the Journey
    2. 2. Muscular System Overview  Muscle: general term for all contractile tissue  Contractile property of muscle tissue allows it to become short and thick in response to nerve impulse and then to relax once impulse removed  Alternative contraction and relaxation causes movement
    3. 3. Muscular System Overview  Muscle cells elongated; resemble fibers such as those in rope  Muscle tissue constructed of bundles of these fibers, each approximately the diameter of a human hair
    4. 4. Types of Muscles
    5. 5. Types of Muscles Skeletal muscles  Voluntary muscles  Under conscious control  Derive name from attachment of muscle to skeletal system  Striated (striped) muscle
    6. 6. Types of Muscles  Smooth muscles  Involuntary muscles  Not under our conscious control  Does not have striped appearance  Found within certain organs, blood vessels, airways; sometimes called visceral muscle
    7. 7. Types of Muscles  Smooth muscles  Allows for internal movement of food  Facilitates movement of blood by changing diameter of blood vessels
    8. 8. Types of Muscles  Cardiac muscle  Involuntary; specialized muscle with striated appearance  Found solely in heart  Contraction of muscle causes heart contract; internal movement (circulation) of blood
    9. 9. Figure 7-1 The three types of muscle: skeletal, cardiac, and smooth.
    10. 10. Test Your Knowledge Review 4 Questions for Section 7-1
    11. 11. Skeletal Muscles  Attached to bones, provide movement for body  Tendons: fibrous tissues that attach skeletal muscles to bones  Ligaments: attach bone to bone  Some muscles attach directly to bone or soft tissue without tendon
    12. 12. Skeletal Muscles  Called voluntary because movement controlled by conscious thought  Responsible for movement, giving body its shape and form, maintaining body posture, and heat generation
    13. 13. Figure 7-2 Anterior and posterior view of major muscles. Shoulder Thoracic Arms & Legs Ribs
    14. 14. Figure 7-2 (continued) Anterior and posterior view of major muscles. Buttocks
    15. 15. Figure 7-3 Skeletal facial muscles.
    16. 16. Figure 7-4 Skeletal muscles of the posterior and anterior trunk
    17. 17. Figure 7-5 Skeletal muscles of the shoulder, arm, and hand
    18. 18. Figure 7-6 Skeletal muscles of the hip and leg
    19. 19. Contraction and Relaxation
    20. 20. Figure 7-7 Coordination of antagonistic muscles to perform movement. Muscles that cause movement are called agonists or primary movers
    21. 21. Contraction and Relaxation
    22. 22. Contraction and Relaxation  Diaphragm: primary Diaphragm mover of breathing  Dome-shaped muscle separates abdominal cavity and thoracic cavity  Responsible for performing major work of bringing atmospheric air into lungs  Muscle under both voluntary and involuntary control
    23. 23. Figure 7-8 The diaphragm: The major muscle of breathing
    24. 24. Movement Terminology  Rotation: circular movement Rotation that occurs around an axis  Abduction: to move away from Abduction midline of body  Adduction: movement toward Adduction midline of body
    25. 25. Figure 7-9 The types of skeletal movement Extension of left forearm. Extension: Extension Increasing angle between two bones connected at a joint Muscle that straightens the joint is called extensor muscle
    26. 26. Figure 7-9 The types of skeletal movement Flexion of left forearm Flexion: Flexion Opposite of extension, decreasing angle between two bones Muscle that bends the joint is called flexor muscle
    27. 27. Figure 7-9 (continued) The types of skeletal movement Flexion and extension of the leg Extension is needed when you kick a football Flexion occurs when you bend your leg to sit down
    28. 28. Ataxia Some muscular diseases can cause ataxia, a condition ataxia of irregular muscle movement and lack of muscle coordination
    29. 29. Test Your Knowledge Review 9 Questions for Section 7-2
    30. 30. Muscular Movement at the Cellular Level How does this muscle tissue cause a coordinated and smooth contraction?
    31. 31. Muscle Contraction Step-by-Step Begins at the Neuromuscular Junction
    32. 32. MUSCLE TISSUE COMPONENTS • • • • • • • • Epimysium Fasciculus Endomysium Perimysium Sarcomere Myofibril Actin Myosin
    33. 33. Functional Unit of the Muscle  Typical muscle surrounded by connective tissue, continuous with tendon, called epimysium  Inside muscle are bundles of muscle fibers surrounded by perimysium called fascicles  Muscle fibers elongated cells up to 12 inches (30 centimeters) in length
    34. 34. Functional Unit of the Muscle  Muscle fiber encased in connective tissue sheath (endomysium); filled with cylinders (myofibrils) endomysium myofibrils  Sarcomeres  Myofibril made of protein threads arranged in contractile units; two types of protein threads Thick myofilaments made up of protein myosin Thin ones made up of protein actin
    35. 35. Functional Unit of the Muscle  Sarcomeres (cont'd)  Actin and myosin filaments arranged in repeating units (sarcomeres) (sarcomeres separated from each other by dark bands called Z lines  Give striated appearance to skeletal muscle  Each myofibril made up of several sarcomeres
    36. 36. ATP and Calcium  Energy molecule adenosine triphosphate (ATP) and calcium (Ca) needed for contraction and relaxation  ATP provides energy to help myosin heads form and break crossbridges with actin  When muscle relaxed, calcium stored away from actin and myosin in sarcoplasmic reticulum (SR)
    37. 37. Sarcoplasmic Reticulum (SR) vs. Endoplasmic Reticulum (ER) SR are found mainly in smooth & skeletal muscles While both have protein molecules in their cells, the endoplasmic reticulum mainly synthesizes protein molecules, while the sarcoplasmic reticulum (a type of smooth ER) stores and pumps calcium ions. The sarcoplasmic reticulum contains large stores of calcium, which it sequesters and then releases when the muscle cell is stimulated
    38. 38. Muscular System: Neuromuscular Junction Watch the Video of “Neuromuscular Junction”
    39. 39. Muscle Contraction Step-by-Step
    40. 40. Muscular System: Muscle Contraction Watch the Video of “Muscle Contraction”
    41. 41. Muscle Contraction Step-by-Step
    42. 42. Muscular Fuel  Muscles, like all tissue, needs fuel in the form of nutrients and oxygen to survive and function  Body stores glycogen in the muscle, where it waits muscle to be converted to useable energy source  When needed, glycogen converted to glucose which releases energy
    43. 43. Muscular Fuel  Muscles with very high demands store fat and use it as energy  Energy release causes heat production; this is why production strenuous/prolonged exercises can overheat our bodies  Higher demand muscles have richer blood supply to carry oxygen to muscles giving those muscles a darker color
    44. 44. Test Your Knowledge Review 6 Questions for Section 7-3
    45. 45. Smooth Muscle  Also called visceral muscle, found in organs (except heart), blood vessels (vasodilatation and vasoconstriction), and bronchial airways vasoconstriction  Ability to expand and contract essential to internal processes of body (digestion and regulation of blood pressure)
    46. 46. Smooth Muscle  During asthma attack, smooth muscles in airways of lungs constrict, making it difficult to get air into and out of lungs  Causes wheezing sound
    47. 47. Smooth Muscle  Special type of smooth muscle (sphincter) found sphincter throughout digestive system  Donut-shaped muscles act as doorways to let materials in and out by alternately contracting and relaxing
    48. 48. Cardiac Muscle  Forms walls of the heart  Contraction of cardiac muscle squeezes blood out of chambers of the heart, causing blood to circulate through the body  Involuntary  Fibers shorter; receive richer supply of blood than any other muscle in body
    49. 49. Cardiac Muscle  Fibers connected by intercalated discs, causing one fiber to discs contract and then pull next one into contraction creating domino effect; contraction occurs, allowing blood to be squeezed out of the heart and into the body  Does not regenerate; damage regenerate often leads to tissue death causing scarring of heart tissue; scar tissue does not help muscles of the heart to contract
    50. 50. Figure 7-11 Heart and intercalated discs.
    51. 51. Muscle Movements in Pairs Pair off with a partner and perform various muscle movements. Check his/her accuracy Movements will show rotation, abduction, adduction, extension and flexion of these body parts:
    52. 52. Exam Chapters 6 and 7 Exam will be on Oct 29 at 9:30 •Multiple Choice •Fill in the Blanks •Short Essays (taken directly from the Short Essays at end of Chap 6 and 7) •Extra Credit: Read page 149 “Muscle Tone”