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Slide 2 Approximately 40% of your body weight Approximately 650 muscles Muscles only pull (they cant push) You have over 30 facial muscles Eye muscles move more than 100,000 times a day Slide 3 1. Skeletal 2. Cardiac 3. Smooth Slide 4 Definition - organs that are composed mainly of skeletal muscle tissue, but they also contain connective tissues, nerves, and blood vessels. Each cell is a single muscle fiber. Muscle fibers form bundles called fascicles. Directly or indirectly attached to the bones of the skeleton Slide 5 Muscle plays six important roles in the body: 1. Produce skeletal movement 2. Maintains posture and body position 3. Support soft tissues (abdominal wall & pelvic cavity) 4. Guard entrances and exits (digestive and urinary tracts) 5. Maintain body temperature (energy is converted to heat) 6. Store nutrient reserves (proteins are broken down & amino acids are used) Slide 6 The muscle fibers in a single fascicle are parallel, but the organization of fascicles in skeletal muscles can vary The arrangement is correlated with muscle power and range of motion (structure determines function) Skeletal muscles are classified as: 1. Parallel muscles (most common) fascicles are parallel to the long axis of the muscle 2. Convergent muscles converge at a common attachment site; fibers spread out and pull in different directions 3. Pennate muscles form a common angle with the tendon 4. Circular muscles cocentrically arranged around an opening Slide 7 Three layers of connective tissue are part of each muscle: 1. Epimysium dense layer of collagen fibers that surround the entire muscle 2. Perimysium divides the muscle into a series of compartments each containing a bundle of muscle fibers (fascicle); contains collagen & elastic fibers, blood vessels and nerves that maintain blood flow 3. Endomysium flexible, elastic connective tissue layer; surrounds the individual skeletal muscle cells and interconnects adjacent muscle fibers Slide 8 Slide 9 At the end of the muscle, the collagen fibers of the epimysium, perimysium, and endomysium come together to form a tendon or aponeurosis Tendons and aponeuroses attach muscles to bone Origin where the fixed end of the muscle attaches to the bone (cartilage or connective tissue) Insertion where the movable end of the muscle attaches to another structure Slide 10 Gastrocnemius calf muscle that extends from the distal portion of the femur to the calcaneus When it contracts it pulls the calcaneus toward the knee Origin femur Insertion - calcaneus Slide 11 Naming of Skeletal Muscles Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings Direction of muscle fibers Example: rectus (straight) Relative size of the muscle Example: maximus (largest) Slide 12 Naming of Skeletal Muscles Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings Location of the muscle Example: many muscles are named for bones (e.g., temporalis) Number of origins Example: triceps (three heads) Slide 13 Naming of Skeletal Muscles Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings Location of the muscles origin and insertion Example: sterno (on the sternum) Shape of the muscle Example: deltoid (triangular) Action of the muscle Example: flexor and extensor Slide 14 Axial muscles arise on the axial skeleton (60% of skeletal muscles) ; position the head and spinal column and move the rib cage Appendicular muscles stabilize and move the appendicular skeleton (40% of skeletal muscles) Slide 15 Head and Neck Muscles Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 6.14 Slide 16 Trunk Muscles Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 6.15 Slide 17 Deep Trunk and Arm Muscles Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 6.16 Slide 18 Muscles of the Pelvis, Hip, and Thigh Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 6.18c Slide 19 Muscles of the Lower Leg Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 6.19 Slide 20 Superficial Muscles: Anterior Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 6.20 Slide 21 Superficial Muscles: Posterior Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 6.21 Slide 22 Agonist (prime mover) a muscle whose contraction is mostly responsible for producing a particular movement Example biceps brachii Antagonist a muscle whose action opposes that of a particular agonist Example triceps brachii Agonists and antagonists are functional opposites Synergists help a larger agonist work efficiently Slide 23 Muscle Tone resting tension in a skeletal muscle Isotonic muscle contraction tension rises and the skeletal muscles length changes (lifting) Isometric muscle contraction the muscle as a whole does not change length, and the tension produced never exceeds the load (holding) Slide 24 Types of Ordinary Body Movements Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings Flexion bending at the joint Extension - straightening at the joint Hyperextension Hyperextension Rotation rotating on axis Abduction moving away from the midline Adduction moving toward the body Circumduction circular movement Slide 25 Body Movements Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 6.13 Slide 26 Dorsifelxion Plantar flexion Special Movements Slide 27 Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings Inversion Eversion Slide 28 Opposition Supination Pronation Slide 29 What is a strain? Strains are injuries that involve the stretching or tearing of a musculo-tendinous (muscle and tendon) structure What is a sprain? A sprain is an injury involving the stretching or tearing of a ligament (tissue that connects bone to bone) Strain vs. Sprain Slide 30 Ankle Sprains Slide 31 Examples of Strains Slide 32 Grade I (mild) sprain or strain involves some stretching or minor tearing of a ligament or muscle. Grade II (moderate) sprain or strain is a ligament or muscle that is partially torn but still intact. Grade III (severe) sprain or strain means that the ligament or muscle is completely torn, resulting in joint instability. Slide 33 Slide 34 R rest I - immobilize (ice) C - compression E - elevation Slide 35 Most surgery for ACL injuries involves replacing the ACL with tissue called a graft Usually an autograft (tendon taken from another part of the body) is used The most common grafts used are the tendon of the kneecap or one of the hamstring tendons Another choice is allograft tissue, which is taken from a deceased donor Slide 36 Repairs an injured elbow ligament (UCL construction) A surgeon replaces the injured UCL with a tendon taken from somewhere else in the patients body Slide 37 Duchenne Muscular Dystrophy (DMD) Definition - One of nine types of muscular dystrophy, a group of genetic, degenerative diseases primarily affecting voluntary muscles. Cause - An absence of dystrophin, a protein that helps keep muscle cells intact. Information obtained from: http://www.mda.org/disease/dmd.html Slide 38 Onset - Early childhood - about 2 to 6 years. Symptoms - Generalized weakness first affecting the muscles of the hips, pelvic area, thighs and shoulders. Calves are often enlarged. Progression - DMD eventually affects all voluntary muscles, and the heart and breathing muscles. Inheritance - X-linked recessive. DMD primarily affects boys, who inherit the disease through their mothers. Women can be carriers of DMD but usually exhibit no symptoms. http://www.youtube.com/watch?v=_ZAOO Hayy4I