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Memmler’s The Human Body in Health and Disease 11 th edition

Memmler’s The Human Body in Health and Disease 11 th edition. Chapter 8 The Muscular System. Types of Muscle. Smooth Cardiac Skeletal. Smooth Muscle. Makes up walls of hollow body organs, respiratory passageways Involuntary movement Cell structure Tapered ends Single, central nucleus

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Memmler’s The Human Body in Health and Disease 11 th edition

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  1. Memmler’s The Human Body in Health and Disease11th edition Chapter 8 The Muscular System

  2. Types of Muscle • Smooth • Cardiac • Skeletal

  3. Smooth Muscle • Makes up walls of hollow body organs, respiratory passageways • Involuntary movement • Cell structure • Tapered ends • Single, central nucleus • No visible bands (striations) • Stimulated by nerve impulses, hormones, stretching

  4. Cardiac Muscle • Makes up wall of heart • Involuntary movement • Cell structure • Branching interconnections • Single, central nucleus • Striated • Membranes are intercalated disks • Stimulated by electrical impulses, nervous stimuli, hormones

  5. Skeletal Muscle • Attached to bones, muscles, or skin • Voluntary movement • Cell structure • Long and cylindrical • Multiple nuclei per cell • Heavily striated • Stimulated by nervous system

  6. Checkpoint 8-1: What are the three types of muscle?

  7. Question:Which type of muscle has intercalated disks? a. smooth muscleb. cardiac musclec. skeletal muscle

  8. Answer:b. cardiac muscle

  9. The Muscular System Skeletal muscle has three primary functions • Skeletal movement • Posture maintenance • Heat generation

  10. Checkpoint 8-2: What are the three main functions of skeletal muscle?

  11. Structure of a Muscle • Fascicles (muscle fibers) • Endomysium • Perimysium • Epimysium (deep fascia) • Tendons

  12. Structure of a skeletal muscle. • Structure of a muscle showing the tendon that attaches it to a bone. (B) Muscle tissue seen under a microscope. Portions of several fascicles are shown with connective tissue coverings. ZOOMING IN • What is the innermost layer of connective tissue in a muscle? • What layer of connective tissue surrounds a fascicle of muscle fibers?

  13. Question:What is the name of the connective tissue structure that connects muscle to bone?a. fascicleb. ligamentc. tendon

  14. Answer: c. tendon

  15. Muscle Cells in Action • Motor unit is a single neuron and all the muscle fibers it • stimulates • Neuromuscular junction (NMJ) • Neurotransmitter • Synaptic cleft • Receptors • Motor end plate

  16. Checkpoint 8-3: Muscles are activated by the nervous system. What is the name of the special synapse where a nerve cell makes contact with a muscle cell? Checkpoint 8-4: What neurotransmitter is involved in the stimulation of skeletal muscle cells?

  17. Neuromuscular junction (NMJ). (A) The branched end of a motor neuron makes contact with the membrane of a muscle fiber (cell). (B) Enlarged view of the NMJ showing release of neurotransmitter (acetylcholine) into the synaptic cleft. (C) Acetylcholine attaches to receptors in the motor end plate, whose folds increase surface area. (D) Electron microscope photograph of the neuromuscular junction.

  18. Properties of Muscle Tissue • Excitability • Action potential • Contractility • Actin • Myosin • Sarcomere • ATP

  19. Sliding filament mechanism of skeletal muscle contraction. • Muscle is relaxed and there is no contact between the actin and myosin filaments. • Cross-bridges form and the actin filaments are moved closer together as the muscle fiber contracts. (C) The cross-bridges return to their original position and attach to new sites to prepare for another pull on the actin filaments and further contraction. ZOOMING IN • Do the actin or myosin filaments change in length as contraction proceeds?

  20. Checkpoint 8-5: What are two properties of muscle cells that are needed for response to a stimulus? Checkpoint 8-6: What are the filaments that interact to produce muscle contraction?

  21. The Role of Calcium Calcium • Is released when nerve fiber stimulates muscle cell • Attaches to proteins blocking receptor sites • Allows cross-bridges to form between actin and myosin • Returns to endoplasmic reticulum (ER), which is called “sarcoplasmic reticulum” in muscle cells.

  22. Energy Sources Muscle contraction requires energy (ATP), oxidized in muscle cells from • Oxygen • Glucose or other usable nutrient Compounds in muscle cells that store oxygen, energy, or nutrients • Myoglobin • Glycogen • Creatine phosphate

  23. Checkpoint 8-7: What mineral is needed to allow actin and myosin to interact? Checkpoint 8-8: Muscle cells obtain energy for contraction from the oxidation of nutrients. What compound is formed in oxidation that supplies the energy for contraction?

  24. Oxygen Consumption • Aerobic glucose metabolism • Anaerobic glucose metabolism • Inefficient production • Lactic acid accumulation • Oxygen debt • Recovery oxygen consumption

  25. Checkpoint 8-9:When muscles work without oxygen, a compound is produced that causes muscle fatigue. What is the name of this compound?

  26. Effects of Exercise • Improved balance, joint flexibility • Increase in muscle size (hypertrophy) • Improvements in muscle tissue • Vasodilation • Strengthened heart muscle • Improved breathing and respiratory efficiency • Weight control • Stronger bones

  27. Types of Muscle Contractions • Partial (muscle tone or tonus) • Isotonic • No change in tension • Muscle length shortens • Movement • Isometric • Great increase in tension • Muscle length unchanged • No movement

  28. Question: The partially contracted state of muscle is known as what? a. tonusb. tensionc. torsion

  29. Answer:a. tonus

  30. The Mechanics of Muscle Movement Tendons attach muscles to bones • Origin—attached to more fixed part of skeleton • Insertion—attached to more moveable part of skeleton

  31. Checkpoint 8-10:Muscles are attached to bones by means of tendons: one attached to a less movable part of the skeleton and one attached to a movable part. What are the names of these two attachment points?

  32. Muscles Work Together • Many muscles function in pairs • Prime movers • Antagonists • Synergists • In development, nervous system must learn to coordinate movement. Children learning new skills may use some muscles unnecessarily or not use the correct muscles.

  33. Checkpoint 8-11: Muscles work together to produce movement. What is the name of the muscle that produces a movement as compared with the muscle that produces an opposite movement?

  34. Question:What is the name for a muscle that helps the prime mover and the antagonist muscles?a. a supplemental b. an effector c. a synergist

  35. Answer: c. a synergist

  36. Levers and Body Mechanics Musculoskeletal system as a lever system • Lever—bone • Fulcrum—joint • Force—applied by muscle Three classes of levers • First class • Second class • Third class—most body systems

  37. Three classes of levers are shown along with tools and anatomic examples that illustrate each type. R = resistance (weight); E = effort (force); F = fulcrum (pivot point).

  38. Checkpoint 8-12: Muscles and bones work together as lever systems. Of the three classes of levers, which one represents the action of most muscles?

  39. Skeletal Muscle Groups Characteristics for naming muscles (often combined) • Location • Size • Shape • Direction of fibers • Number of heads (attachment points) • Action

  40. Superficial muscles, anterior view. Associated structure is labeled in parentheses.

  41. Superficial muscles, posterior view. Associated structures are labeled in parentheses.

  42. Muscles of the Head • Facial expression (orbicularis) muscles • Orbicularis oculi • Orbicularis oris • Levator palpebrae superioris • Buccinator • Mastication (chewing) muscles • Temporalis • Masseter • Intrinsic • Extrinsic

  43. Muscles of the head. Associated structure is labeled in parentheses. ZOOMING IN •Which of the muscles in this illustration is named for a bone it is near?

  44. Question: What is the name for the muscle that surrounds the eye?a. orbicularis oculib. orbicularis orisc. frontalis

  45. Answer:a. orbicularis oculi

  46. Muscles of the Neck • Are ribbonlike • Extend up, down, or obliquely • Extend in several layers in a complex manner • Most common is sternocleidomastoid

  47. Muscles of the Upper Extremities • Position the shoulder • Move the arm • Move the forearm and hand

  48. Muscles That Move the Shoulder and Arm • Trapezius • Latissimus dorsi • Pectoralis major • Serratus anterior • Deltoid • Rotator cuff • Supraspinatus • Infraspinatus • Teres minor • Subscapularis

  49. Muscles That Move the Forearm and Hand • Brachialis • Biceps brachii • Brachioradialis • Triceps brachii • Flexor carpi • Extensor carpi • Flexor digitorum • Extensor digitorum

  50. Muscles that move the forearm and hand.

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