Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Chapter 8: The Muscular System
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease Key Terms acetylcholineinsertion spasm actinsynapse myalgia myoglobin tendon bursitismyosintonus neuromuscular junction tropomyosin neurotransmitter troponin origin glycogen
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease Types of Muscle Learning Outcome 1.Compare the three types of muscle tissue.
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease Types of Muscle
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease Types of Muscle ✓ Checkpoint 8-1What are the three types of muscle? Exam Question: Which ones are voluntary? Which one is visceral? Which one is in heart? Which ones are striated?
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease Types of Muscle ? Pop Quiz 8.1 Which type of muscle tissue is striated and involuntary? A)Cardiac B)Intercalated C)Smooth D)Skeletal
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease Types of Muscle ? Pop Quiz Answer 8.1 Which type of muscle tissue is striated and involuntary? A)Cardiac B)Intercalated C)Smooth D)Skeletal
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease The Muscular System Skeletal Muscle Has Three Primary Functions: Skeletal movement Posture maintenance Heat generation
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease The Muscular System Muscle Cells in Action Neuromuscular junction (NMJ): The point at which a nerve fiber contacts a muscle fiber –A type of synapse –NMJ anatomy Motor neuron Neurotransmitter (acetylcholine; ACh) Motor end plate (on muscle fiber) Contains acetylcholine receptors
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease The Muscular System Muscle Cells in Action NMJ allows motor neuron to stimulate muscle fiber to become electrically excited (action potential) Action potential stimulates muscle contraction Events at the NMJ –Ach is released from motor neuron into synaptic cleft –Ach diffuses across synaptic cleft towards motor end plate –Ach binds to receptors on motor end plate and stimulates action potential
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease Figure 8-2 Nerve supply to a skeletal muscle and the NMJ.
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease The Muscular System ✓ Checkpoints 8-2What are the three main functions of skeletal muscle? 8-3What is the name of the special synapse in which a nerve cell makes contact with a muscle cell? 8-4What neurotransmitter is involved in the stimulation of skeletal muscle cells?
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease The Muscular System Muscle Cells in Action The sarcomere is the functional unit of contraction in the skeletal muscle fiber Sarcomere anatomy: –Thick filaments (myosin) –Thin filaments (actin) –Regulatory proteins Troponin Tropomyosin
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease Figure 8-3 Detailed structure of a skeletal muscle cell.
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease The Muscular System Muscle Cells in Action Sarcomeres contract via the sliding filament mechanism: –Myosin heads bind to actin, forming cross-bridges –Using stored energy, myosin heads pull actin filaments together within the sarcomeres and the cell shortens –New ATP is used to detach myosin heads and move them back into position for another “power stroke”
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease Figure 8-4 Sliding filament mechanism of skeletal muscle contraction. Sliding filament mechanism of skeletal muscle contraction.
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease The Muscular System Muscle Cells in Action Calcium regulates sarcomeric contraction within the muscle cell: –Action potential from NMJ travels to sarcoplasmic reticulum (SR) –SR releases calcium into cytoplasm –Calcium shifts troponin and tropomyosin off of thin filament so that binding sites on actin are exposed –Sliding filament mechanism now able to proceed –Muscle relaxes when stimulation ends and calcium is pumped back into SR
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease Figure 8-5 Role of calcium in muscle contraction.
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease The Muscular System Summary of Events in a Muscle Contraction 1.ACh is released from neuron ending into synaptic cleft at NMJ 2.ACh binds to motor end plate and produces action potential 3.Action potential travels to sarcoplasmic reticulum (SR) 4.SR releases calcium into cytoplasm 5.Calcium shifts troponin and tropomyosin so that binding sites on actin are exposed
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease The Muscular System Summary of Events in a Muscle Contraction (continued) 6.Myosin heads bind to actin, forming cross-bridges 7.Using stored energy, myosin heads pull actin filaments together within sarcomeres and cell shortens 8.New ATP is used to detach myosin heads and move them back to position for another “power stroke” 9.Muscle relaxes when stimulation ends and calcium is pumped back into SR
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease The Muscular System ✓ Checkpoints 8-6What filaments interact to produce muscle contraction? 8-7What mineral is needed for interaction of the contractile filaments? Exam Question: What are the regulatory proteins in muscle fibers? What is the source of Energy for contraction?
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease The Muscular System ? Pop Quiz 8.3 The two filaments that form cross-bridges are A)Actin and troponin B)Tropomyosin and myosin C)Actin and myosin D)Troponin and tropomyosin
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease The Muscular System ? Pop Quiz Answer 8.3 The two filaments that form cross-bridges are A)Actin and troponin B)Tropomyosin and myosin C)Actin and myosin D)Troponin and tropomyosin
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease The Muscular System Energy Sources Muscle contraction requires ATP Skeletal muscle prefers to produces ATP via aerobic metabolism, which requires –Oxygen –Glucose Storage compounds ensure an adequate supply of oxygen and glucose for aerobic ATP metabolism –Myoglobin –Glycogen
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease The Muscular System Energy Sources During strenuous activity, muscle cells use anaerobic ATP metabolism, which does not require ATP –Breakdown of creatine phosphate –Anaerobic glycolysis Lactic acid accumulation and oxygen debt Excess postexercise oxygen consumption –After strenuous exercise, person takes in extra oxygen (via rapid breathing) to remove lactic acid and replenish energy stores
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease The Muscular System Effects of Exercise Improved balance, joint flexibility Increased muscle size (hypertrophy) Improved muscle tissue Vasodilation Strengthened heart muscle Improved breathing and respiratory efficiency Weight control Stronger bones
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease The Muscular System ✓ Checkpoints 8-8What compound is formed in oxidation of nutrients that supplies the energy for contraction? 8-9What acid accumulates during anaerobic metabolism?
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease The Mechanics of Muscle Movement Tendons attach muscles to bones. –Origin: Attached to more fixed part of skeleton –Insertion: Attached to more movable part of skeleton
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease Figure 8-6 Muscle attachments to bones.
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease Figure 8-8 Superficial muscles, anterior view.
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease Figure 8-9 Superficial muscles, posterior view.
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease Skeletal Muscle Groups Muscles That Move the Shoulder and Arm
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease Skeletal Muscle Groups Muscles That Move the Forearm and Hand
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease Figure 8-11 Muscles that move the forearm and hand. What does carpi refer to in the names of muscles? Digitorum?
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease Skeletal Muscle Groups Muscles of the Trunk
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease Figure 8-12 Muscles of respiration.
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease What does rectus mean? Oblique? Figure 8-13 Muscles of the abdominal wall.
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease Skeletal Muscle Groups Muscles That Move the Leg and Thigh
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease Skeletal Muscle Groups Muscles That Move the Leg and Thigh (continued)
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease Figure 8-15 Muscles of the thigh. How many muscles make up the quadriceps femoris?
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease Skeletal Muscle Groups ✓ Checkpoints 8-14What muscle is most important in breathing?
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease Muscular Disorders Common Terms Used When Describing Muscular Disorders Spasms –Colic –Seizure –Convulsion Cramps Atrophy
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease Muscular Disorders Muscle Injuries Strains Sprains
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease Muscular Disorders Diseases of Muscle Muscular dystrophy Myalgia –Myositis Fibromyalgia syndrome (FMS) Bursitis
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease Muscular Disorders Disorders of Associated Structures Bursitis Tendinitis Carpal tunnel syndrome
Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Cohen: Memmler’s The Human Body in Health and Disease Figure 8-17 Carpal tunnel syndrome.