A & P Ch 6 Musclular System Student PPT

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A & P Ch 6 Musclular System Student PPT

  1. 1. Muscular System – Ch 6 Dancing frog legs: http://www.youtube.com/watch?v=dmQSP8uUwL8© 2012 Pearson Education, Inc.
  2. 2. The Muscular System Ch 6 GoalsOverview of Muscle Tissues1. Describe similarities and differences in the structure and function of the three types of muscle tissue and indicate where they are found in the body.2. State the 4 main functions of the muscular system and list the main parts of the muscular system.3. Define and explain the role of the following: endomysium, perimysium, epimysium, tendon, and aponeurosis. and label them on a diagram.Microscopic Anatomy of Skeletal Muscle4. Describe the microscopic structure of skeletal muscle and explain the role of actin- and myosin- containing myofilaments and label a sarcomere diagram.Skeletal Muscle Activity5. Describe how an action potential is initiated in a muscle cell. (neuromuscular junction, acetylcholine, Ca++…)6. Describe the events of muscle cell contraction (myosin heads binding to actin fibers & sliding them past…).8. Describe three ways in which ATP is regenerated during muscle activity.9. Define oxygen debt and muscle fatigue and list possible causes of muscle fatigue.10. Describe the effects of aerobic and resistance exercise on skeletal muscles and other body organs.Muscle Movements, Types, and Names11. Define origin, insertion, prime mover, antagonist, synergist, and fixator as they relate to muscles.12. Demonstrate or identify the different types of body movements. (flexion, extension, hyperextension, rotation, abduction, adduction, supination, pronation, opposition)Gross Anatomy of Skeletal Muscles14. Name and locate the major muscles of the human body (on a torso model, muscle chart, or diagram) and state the action of each.© 2012 Pearson Education, Inc.
  3. 3. The Muscular SystemMuscles are responsible forall types of body movement • Movement of • Skeleton • Facial expressions • Eyeball • Goosebumps • Iris to control amt of light into eye • Heart beating • Substances through body© 2012 Pearson Education, Inc.
  4. 4. Characteristics of Muscles •Skeletal and smooth muscle cells are elongated (muscle cell = muscle fiber) •Contraction and shortening of muscles is due to the movement of microfilaments •All muscles share some terminology •Prefixes myo and mys refer to ―muscle‖ •Prefix sarco refers to ―flesh‖ • Composes almost 50% of body mass© 2012 Pearson Education, Inc.
  5. 5. 3 Basic Muscle Types© 2012 Pearson Education, Inc.
  6. 6. Skeletal Muscle Characteristics• Most are attached by tendons to bones• Cells are multinucleate• Striated—have visible banding• Voluntary—subject to conscious control• Responds fastest to stimuli© 2012 Pearson Education, Inc.
  7. 7. Connective Tissue Wrappings of Skeletal Muscle• Cells are surrounded and bundled by connective tissue • Endomysium—encloses a single muscle fiber (cell) • Perimysium—wraps around a fascicle (bundle) of muscle fibers • Epimysium—covers the entire skeletal muscle • Fascia—on the outside of the epimysium; covers & separates muscles Short video showing live human fascicles being stimulated http://www.youtube.co m/watch?v=1- dpnqNupns© 2012 Pearson Education, Inc.
  8. 8. Muscle fiber Blood vessel (cell) Perimysium Epimysium (wraps entire muscle) Fascicle (wrapped by perimysium) Endomysium (between fibers) Tendon Bone© 2012 Pearson Education, Inc. Figure 6.1
  9. 9. Skeletal Muscle Attachments• Epimysium blends into a connective tissue attachment • Tendons—cord-like structures • Mostly collagen fibers • Often cross a joint due to toughness and small size • Aponeuroses—sheet-like structures • Attach muscles indirectly to bones, cartilages, or connective tissue coverings© 2012 Pearson Education, Inc.
  10. 10. Skeletal MuscleAttachments• Sites of muscle attachment • Bones • Cartilages • Connective tissue coverings • Some facial muscles attached from skull to skin – allow for facial expressions© 2012 Pearson Education, Inc.
  11. 11. Skeletal Muscle Functions Yea, I’m hot •Produce movement stuff. •Maintain posture •Stabilize joints •Generate heat© 2012 Pearson Education, Inc.
  12. 12. Microscopic Anatomy of Skeletal Muscle •Sarcolemma—specialized plasma membrane •Myofibrils—long organelles inside muscle cell •Sarcoplasmic reticulum—specialized smooth endoplasmic reticulum© 2012 Pearson Education, Inc.
  13. 13. Sarcolemma Myofibril Dark Light Nucleus (A) band (I) band (a) Segment of a muscle fiber (cell)© 2012 Pearson Education, Inc. Figure 6.3a
  14. 14. Microscopic Anatomy of Skeletal Muscle• Myofibrils are aligned to give distinct bands • I band = light band • Contains only thin filaments • A band = dark band • Contains the entire length of the thick filaments© 2012 Pearson Education, Inc.
  15. 15. Microscopic Anatomy of Skeletal Muscle• Sarcomere—contractile unit of a muscle fiber (area b/t two Z discs)• Organization of the sarcomere • Myofilaments • Thick filaments = myosin filaments • Thin filaments = actin filaments© 2012 Pearson Education, Inc.
  16. 16. Microscopic Anatomy of Skeletal Muscle• Thick filaments = myosin filaments • Composed of the protein myosin • Has ATPase enzymes • Myosin filaments have heads (extensions, or cross bridges) • Myosin and actin overlap somewhat• Thin filaments = actin filaments • Composed of the protein actin • Anchored to the Z disc© 2012 Pearson Education, Inc.
  17. 17. Sarcomere M line Z disc Z disc Thin (actin) filament Thick (myosin) filament (c) Sarcomere (segment of a myofibril)© 2012 Pearson Education, Inc. Figure 6.3c
  18. 18. Microscopic Anatomy of Skeletal Muscle• At rest, within the A band there is a zone that lacks actin filaments • Called either the H zone or bare zone• Sarcoplasmic reticulum (SR) • Stores and releases calcium • Surrounds the myofibril© 2012 Pearson Education, Inc.
  19. 19. Thick filament Bare zone Thin filament (d) Myofilament structure (within one sarcomere)© 2012 Pearson Education, Inc. Figure 6.3d
  20. 20. The Nerve Stimulus and Action Potential • Skeletal muscles must be stimulated by a motor neuron (nerve cell) to contract • Motor unit—one motor neuron and all the skeletal muscle cells stimulated by that neuron© 2012 Pearson Education, Inc.
  21. 21. Axon terminals at neuromuscular junctions Spinal cord Motor Motor unit 1 unit 2 Nerve Axon of Motor neuron motor cell bodies neuron Muscle Muscle fibers (a)© 2012 Pearson Education, Inc. Figure 6.4a
  22. 22. The Nerve Stimulus and Action Potential Axon terminals at neuromuscular junctions Muscle fibers •Neuromuscular junction •Association site of axon terminal of the motor neuron and muscle Branching axon to motor unit (b)© 2012 Pearson Education, Inc. Figure 6.4b
  23. 23. © 2012 Pearson Education, Inc. Figure 6.5
  24. 24. The Nerve Stimulus and Action Potential •Synaptic cleft •Gap between nerve and muscle •Nerve and muscle do not make contact •Area between nerve and muscle is filled with interstitial fluid© 2012 Pearson Education, Inc.
  25. 25. Transmission of Nerve Impulse to Muscle Synaptic vesicle containing ACh 1 Action potential reaches axon terminal of motor neuron. Axon terminal of motor neuron Mitochondrion 2 Calcium (Ca2+) channels Ca2+ Ca2+ open and Ca2+ enters the axon Synaptic terminal. Sarcolemma cleft Fusing synaptic vesicle Sarcoplasm 3 Ca2+ entry causes some ACh of muscle fiber synaptic vesicles to release their Folds of contents (acetylcholine, a ACh receptor sarcolemma neurotransmitter) by exocytosis. 4 Acetylcholine diffuses across the synaptic cleft and binds to receptors in the sarcolemma.© 2012 Pearson Education, Inc. Figure 6.5, step 4
  26. 26. Transmission of Nerve Impulse to Muscle Ion channel in 5 ACh binds and channels open Na+ K+ sarcolemma opens; that allow simultaneous passage ions pass. of Na+ into the muscle fiber and K+ out of the muscle fiber. More Na+ ions enter than K+ ions leave and this produces a local change in the electrical conditions of the membrane (depolarization), which eventually leads to an action potential.© 2012 Pearson Education, Inc. Figure 6.5, step 5
  27. 27. Transmission of Nerve Impulse to Muscle ACh Degraded ACh Ion channel closed; Na+ ions cannot pass. 6 ACh effects are ended by its breakdown in the synaptic cleft by the enzyme acetylcholinesterase. Acetylcholinesterase K+© 2012 Pearson Education, Inc. Figure 6.5, step 6
  28. 28. The Sliding Filament Theory of Muscle Contraction• Activation by nerve causes myosin heads (cross bridges) to attach to binding sites on the thin filament• Myosin heads then bind to the next site of the thin filament and pull them toward the center of the sarcomere• This continued action causes a sliding of the myosin along the actin• The result is that the muscle is shortened (contracted)© 2012 Pearson Education, Inc.
  29. 29. Myosin Actin Z H Z I A I (a) Z Z I A I (b) Figure 6.7a–b© 2012 Pearson Education, Inc.
  30. 30. © 2012 Pearson Education, Inc.
  31. 31. Muscle Response to Strong Stimuli •Muscle force depends upon the number of fibers stimulated •More fibers contracting results in greater muscle tension •Muscles can continue to contract unless they run out of energy© 2012 Pearson Education, Inc.
  32. 32. Energy for Muscle Contraction •Initially, muscles use stored ATP for energy •ATP bonds are broken to release energy •Only 4–6 seconds worth of ATP is stored by muscles •After this initial time, other pathways must be utilized to produce ATP – there are 3 pathways to produce ATP© 2012 Pearson Education, Inc.
  33. 33. Energy for Muscle Contraction •Direct phosphorylation of ADP by creatine phosphate (CP) •CP supplies are exhausted in less than 15 seconds •About 1 ATP is created per CP molecule© 2012 Pearson Education, Inc.
  34. 34. Energy for Muscle Contraction• Anaerobic glycolysis and lactic acid formation • Reaction that breaks down glucose without oxygen • Glucose is partially broken down to produce about 2 ATP• This reaction is not as efficient, but is fast • Huge amounts of glucose are needed • Lactic acid produces muscle fatigue© 2012 Pearson Education, Inc.
  35. 35. Energy for Muscle Contraction•Aerobic respiration (with Oxygen) •Glucose is broken down to CO2 & H2O, releasing energy (about 32 ATP) •In mitochondria •Slower reaction that requires continuous O2© 2012 Pearson Education, Inc.
  36. 36. Muscle Fatigue and Oxygen Deficit •When a muscle is fatigued, it is unable to contract even with a stimulus •Common cause for muscle fatigue is oxygen debt •Oxygen must be ―repaid‖ to tissue to remove oxygen deficit •Oxygen is required to get rid of accumulated lactic acid •Increasing acidity (from lactic acid) and lack of ATP causes the muscle to contract less© 2012 Pearson Education, Inc.
  37. 37. Effect of Exercise on Muscles •Exercise increases muscle size, strength, and endurance •Aerobic (endurance) exercise (biking, jogging) results in stronger, more flexible muscles with greater resistance to fatigue •Makes body metabolism more efficient •Improves digestion, coordination •Resistance (isometric) exercise (weight lifting) increases muscle size and strength© 2012 Pearson Education, Inc.
  38. 38. Five Golden Rules of Skeletal Muscle Activity 1. With a few exceptions, all skeletal muscles cross at least one joint. 2. Typically, the bulk of a skeletal muscle lies proximal to the joint crossed. 3. All skeletal muscles have at least two attachments: the origin and the insertion. 4. Skeletal muscles can only pull; they never push. 5. During contraction, a skeletal muscle insertion moves toward the origin.© 2012 Pearson Education, Inc.
  39. 39. Muscles and Body Movements •Movement is attained due to a muscle moving an attached bone •Muscles are attached to at least two points •Origin •Attachment to a moveable bone •Insertion •Attachment to an immovable bone© 2012 Pearson Education, Inc.
  40. 40. Muscle contracting Origin Brachialis Tendon Insertion© 2012 Pearson Education, Inc. Figure 6.12
  41. 41. Types of Body Movements • Flexion • Decreases the angle of the joint • Brings two bones closer together • Typical of bending hinge joints like knee and elbow or ball- and-socket joints like the hip • Extension • Opposite of flexion • Increases angle between two bones • Typical of straightening the elbow or knee • Extension beyond 180° is hypertension • Great video showing these: http://www.youtube.com/watch?v=-GCgaoRdeaU© 2012 Pearson Education, Inc.
  42. 42. © 2012 Pearson Education, Inc. Figure 6.13a
  43. 43. © 2012 Pearson Education, Inc. Figure 6.13b
  44. 44. Types of Body Movements •Rotation •Movement of a bone around its longitudinal axis •Common in ball-and-socket joints •Example is when you move atlas around the dens of axis (shake your head ―no‖)© 2012 Pearson Education, Inc.
  45. 45. © 2012 Pearson Education, Inc. Figure 6.13c
  46. 46. Types of Body Movements •Abduction •Movement of a limb away from the midline •Adduction •Opposite of abduction •Movement of a limb toward the midline© 2012 Pearson Education, Inc.
  47. 47. Special Movements •Supination •Forearm rotates laterally so palm faces anteriorly •Radius and ulna are parallel •Pronation •Forearm rotates medially so palm faces posteriorly •Radius and ulna cross each other like an X© 2012 Pearson Education, Inc.
  48. 48. © 2012 Pearson Education, Inc. Figure 6.13g
  49. 49. Special Movements •Opposition •Move thumb to touch the tips of other fingers on the same hand© 2012 Pearson Education, Inc.
  50. 50. © 2012 Pearson Education, Inc. Figure 6.13h
  51. 51. Types of Muscles •Prime mover—muscle with the major responsibility for a certain movement •Antagonist—muscle that opposes or reverses a prime mover •Synergist—muscle that aids a prime mover in a movement and helps prevent rotation •Fixator—stabilizes the origin of a prime mover© 2012 Pearson Education, Inc.
  52. 52. Naming Skeletal Muscles •By direction of muscle fibers •Example: Rectus (straight) •By relative size of the muscle •Example: Maximus (largest)© 2012 Pearson Education, Inc.
  53. 53. Naming Skeletal Muscles •By location of the muscle •Example: Temporalis (temporal bone) •By number of origins •Example: Triceps (three heads)© 2012 Pearson Education, Inc.
  54. 54. Naming Skeletal Muscles •By location of the muscle’s origin and insertion •Example: Sterno (on the sternum) •By shape of the muscle •Example: Deltoid (triangular) •By action of the muscle •Example: Flexor and extensor (flexes or extends a bone)© 2012 Pearson Education, Inc.
  55. 55. Head and Neck Muscles •Facial muscles •Frontalis—raises eyebrows •Orbicularis oculi—closes eyes, squints, blinks, winks •Orbicularis oris—closes mouth and protrudes the lips •Buccinator—flattens the cheek, chews •Zygomaticus—raises corners of the mouth •Chewing muscles •Masseter—closes the jaw and elevates mandible •Temporalis—synergist of the masseter, closes jaw© 2012 Pearson Education, Inc.
  56. 56. Head and Neck Muscles •Neck muscles •Platysma—pulls the corners of the mouth inferiorly •Sternocleidomastoid—flexes the neck, rotates the head© 2012 Pearson Education, Inc.
  57. 57. Cranial Frontalis aponeurosis Temporalis Orbicularis oculi Occipitalis Zygomaticus Buccinator Masseter Orbicularis Sternocleidomastoid oris Trapezius Platysma© 2012 Pearson Education, Inc. Figure 6.16
  58. 58. Muscles of Trunk, Shoulder, Arm •Anterior muscles •Pectoralis major—adducts and flexes the humerus •Intercostal muscles •External intercostals—raise rib cage during inhalation •Internal intercostals—depress the rib cage to move air out of the lungs when you exhale forcibly© 2012 Pearson Education, Inc.
  59. 59. Muscles of Trunk, Shoulder, Arm •Muscles of the abdominal girdle •Rectus abdominis—flexes vertebral column and compresses abdominal contents (defecation, childbirth, forced breathing) •External oblique—flex vertebral column; rotate trunk and bend it laterally •Internal oblique—flex vertebral column; rotate trunk and bend it laterally •Transversus abdominis—compresses abdominal contents© 2012 Pearson Education, Inc.
  60. 60. Muscles of Trunk, Shoulder, Arm •Posterior muscles •Trapezius—elevates, depresses, adducts, and stabilizes the scapula •Latissimus dorsi—extends and adducts the humerus •Erector spinae—back extension •Quadratus lumborum—flexes the spine laterally •Deltoid—arm abduction© 2012 Pearson Education, Inc.
  61. 61. Muscles of Trunk, Shoulder, Arm •Muscles that arise from the shoulder girdle and cross the shoulder joint to insert into the humerus include: •Pectoralis major •Latissimus dorsi •Deltoid PLAY A&P Flix™: Muscles that act on the shoulder joint and humerus: An overview. PLAY A&P Flix™: Muscles of the pectoral girdle. PLAY A&P Flix™: Muscles that cross the glenohumeral joint. PLAY A&P Flix™: Movement at the glenohumeral joint: An overview.© 2012 Pearson Education, Inc.
  62. 62. Muscles of the Upper Limb •Biceps brachii—supinates forearm, flexes elbow •Brachialis—elbow flexion •Brachioradialis—weak muscle; elbow flexion •Triceps brachii—elbow extension (antagonist to biceps brachii) PLAY A&P Flix™: The elbow joint and forearm: An overview. PLAY A&P Flix™: Muscles of the elbow joint. PLAY A&P Flix™: Movement at the elbow joint.© 2012 Pearson Education, Inc.
  63. 63. Muscles of the Upper Limb •Muscles of the forearm, which insert on the hand bones and cause their movement include: •Flexor carpi—wrist flexion •Flexor digitorum—finger flexion •Extensor carpi—wrist extension •Extensor digitorum—finger extension PLAY A&P Flix™: Muscles that act on the wrist and fingers: An overview. PLAY A&P Flix™: Movements of the wrist and fingers (a). PLAY A&P Flix™: Movements of the wrist and fingers (b).© 2012 Pearson Education, Inc.
  64. 64. Muscles of the Lower Limb •Muscles causing movement at the hip joint include: •Gluteus maximus—hip extension •Gluteus medius—hip abduction, steadies pelvis when walking •Iliopsoas—hip flexion, keeps the upper body from falling backward when standing erect •Adductor muscles—adduct the thighs PLAY A&P Flix™: Muscles that act on the hip joint and femur: An overview. PLAY A&P Flix™: Movement at the hip joint: An overview.© 2012 Pearson Education, Inc.
  65. 65. Gluteus medius Gluteus maximus Adductor magnus Iliotibial tract Biceps femoris Semitendinosus Hamstring group Semimembranosus Gastrocnemius (a)© 2012 Pearson Education, Inc. Figure 6.20a
  66. 66. 12th 12th rib thoracic vertebra Iliac crest lliopsoas Psoas major lliacus 5th lumbar vertebra Anterior superior iliac spine Sartorius Adductor group Rectus femoris Quadriceps Vastus lateralis Vastus medialis Patella Patellar ligament (c)© 2012 Pearson Education, Inc. Figure 6.20c
  67. 67. Muscles of the Lower Limb •Muscles causing movement at the knee joint •Hamstring group—thigh extension and knee flexion •Biceps femoris •Semimembranosus •Semitendinosus© 2012 Pearson Education, Inc.
  68. 68. Gluteus medius Gluteus maximus Adductor magnus Iliotibial tract Biceps femoris Semitendinosus Hamstring group Semimembranosus Gastrocnemius (a)© 2012 Pearson Education, Inc. Figure 6.20a
  69. 69. Muscles of the Lower Limb •Muscles causing movement at the knee joint •Sartorius—flexes the thigh •Quadriceps group—extends the knee •Rectus femoris •Vastus muscles (three) PLAY A&P Flix™: Muscles that cross the knee joint: An overview.© 2012 Pearson Education, Inc.
  70. 70. Muscles of the Lower Limb •Muscles causing movement at ankle and foot •Tibialis anterior—dorsiflexion, foot inversion •Extensor digitorum longus—toe extension and dorsiflexion of the foot •Fibularis muscles—plantar flexion, foot eversion •Soleus—plantar flexion PLAY A&P Flix™: Muscles that act on the ankle and foot: An overview. PLAY A&P Flix™: Posterior muscles that act on the ankle and foot. PLAY A&P Flix™: Movements of the ankle and foot.© 2012 Pearson Education, Inc.
  71. 71. Fibularis longus Tibia Fibularis brevis Soleus Tibialis anterior Extensor digitorum longus Fibularis tertius (a)© 2012 Pearson Education, Inc. Figure 6.21a
  72. 72. Gastrocnemius Soleus Calcaneal (Achilles) tendon Medial malleolus Lateral malleolus (b)© 2012 Pearson Education, Inc. Figure 6.21b
  73. 73. Facial • Frontalis Facial • Orbicularis oculi • Temporalis • Zygomaticus • Masseter • Orbicularis oris Neck Shoulder • Platysma • Trapezius • Sternocleidomastoid Thorax • Deltoid • Pectoralis minor • Pectoralis major Arm • Serratus anterior • Triceps brachii • Biceps brachii • Intercostals • Brachialis Abdomen • Rectus abdominis Forearm • External oblique • Brachioradialis • Internal oblique • Flexor carpi radialis • Transversus abdominis Pelvis/thigh • lliopsoas Thigh • Sartorius • Adductor muscle Thigh (Quadriceps) • Rectus femoris • Gracilis • Vastus lateralis • Vastus medialis Leg • Fibularis longus Leg • Extensor digitorum longus • Gastrocnemius • Tibialis anterior • Soleus© 2012 Pearson Education, Inc. Figure 6.22
  74. 74. Neck • Occipitalis • Sternocleidomastoid • Trapezius Shoulder/Back • Deltoid Arm • Triceps brachii • Brachialis • Latissimus dorsi Forearm • Brachioradialis • Extensor carpi radialis longus • Flexor carpi ulnaris • Extensor carpi ulnaris Hip • Extensor digitorum • Gluteus medius • Gluteus maximus Thigh lliotibial tract • Adductor muscle • Hamstrings: Biceps femoris Semitendinosus Semimembranosus Leg • Gastrocnemius • Soleus • Fibularis longus Calcaneal (Achilles) tendon© 2012 Pearson Education, Inc. Figure 6.23

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