Muscle gross anatomy Today s Layout Exercise 12 Skeletal Muscle Structure Exercise 11 Joint Movements Exercise 14 Skeletal Muscles and Actions Muscle Practice Skeletal Muscle Structure Function Exercise 12 Organs comprised of skeletal muscle tissue and CT Locomotion Muscle fibers contract and cause movement Posture Signals for contraction carried by neurons Facial expression Maintenance of body temp Skeletal Muscle Structure Endomysium layer of areolar connective tissue surrounding individual muscle fibers Fascicle a bundle of individual muscle fibers Perimysium dense regular connective tissue surrounds fascicles Muscle formed by groups of fascicles Epimysium dense regular connective tissue surrounds muscles Tendons formed from endomysium perimysium and epimysium that extend beyond each muscle fiber that attach the muscle to bone Skeletal Muscle Structure endomyseum peromyseum Skeletal Muscle Fibers Sarcolemma plasma membrane Conducts APs Contains T tubules 4 Sarcoplasmic Reticulum 5 Stores Ca2 ions part of AP Contains terminal cisternae 1 broad next to t tubules Skeletal Muscle Structure Terminal cisternae Myofibril SR Endomysium Muscle fiber Sarcolemma T tubule blue ring Skeletal Muscle Fibers Thick Filaments Myosin tails form thick filament Myosin heads project toward thin filament important for contraction Thin Filaments Actin tropomyosin and troponin actin major Actin contains binding sites for myosin Tropomyosin nestled between actin functional Troponin binds at intervals along tropomyosin strand functional Sarcomere functional part of muscle fiber actin myosin filaments thick I Bands 1 Thin actin filaments only H Zone 2 Thick myosin filaments just thick A Bands 3 Thick and Thin filaments Z Discs 4 Separate sarcomeres dividing point between thin filaments M Line 5 Middle of sarcomere dividing5point between thick filaments just thin 4 1 partial 3 2 Thick and Thin filaments to thin Myosin head attach relax pulls tight Actin red Troponin green Tropomyosin yellow identify regions and what thin thick is made up of Exercise 11 Skip pgs 159 163 167 Muscle Attachment Origin nonmoving point of attachment when a muscle never moves contracts Insertion moves toward the origin Majority of tension developed when a muscle contracts is focused here moves Muscle Movement Agonist Prime mover flexing forearm bicep brachii Synergist Helps the agonist Antagonist Works against the agonist flexing forearm triceps on opposite side maintan smooth movement Fixator Stabilizes the origin of the prime mover Efficiency there to help stabilize origin point Flexion and Extension B A A A B B A Flexion of the head B Extension of the head A Flexion of the arm B Extension of the arm anatomical position fully extended hyperextension past anatomical position A Flexion of the forearm B Extension of the forearm Flexion and Extension B A A B A Flexion of the thigh B Extension of the thigh A Flexion of the leg B Extension of the leg Abduction and Adduction towards middle in away from middle out A A B A Abduction of the arm B Adduction of the arm B A Abduction of the thigh B Adduction of the thigh Circumduction making circle Circumduction of the arm Circumduction of the thigh Lateral rotation Medial rotation Rotation A B rotation left or right A Lateral rotation of the arm B Medial rotation of the arm Rotation of the head Pronation and Supination 5 Pronation of the forearm turns palm posteriorly 6 Supination of the forearm up turns palm anteriorly down Elevation and Depression Elevation of the mandible Depression of the mandible Protraction and Retraction Protraction of the mandible Retraction of the mandible Movement of the Hand A B A A Abduction of the hand B Adduction of the hand B A Flexion of the hand B Extension of the hand Movement of the Fingers A Abduction of the thumb B Adduction of the thumb C Extension of the thumb D Flexion of the thumb E Opposition of the thumb F Abduction of the fingers G Adduction of the fingers F G Movements of the Foot 1 Inversion of the foot standing outside 2 Eversion of the foot standing inside up 3 Dorsiflexion of the foot 4 Plantarflexion of the foot down Preceptor Activity Exercise 14 Skeletal Muscles and Actions Naming Skeletal Muscles Direction of muscle fiber Rectus Transverse Oblique Size Maximus Minimus Longus Brevis Location Named by the bone to which the muscle attaches or region within which the muscle is located Shape Deltoid Rhomboid Trapezius Number of origins Biceps Triceps Quadriceps Action Named for the action that the muscle performs Learning Skeletal Muscles Only need to learn muscles listed in handout You do not need to memorize origins and insertions of muscles However you must be able to predict action given muscle s origin and insertion insertion pulled towards point of origins Example Predict one action performed by a muscle that originates on the upper cervical vertebrae and inserts on superior portion of vertebral border of scapula Muscles of Face Head and Neck Frontalis Zygomaticus major Occipitalis Sternocleidomastoid Masseter Temporalis Muscles of Face Head and Neck Orbicularis oculi not on models just on pics know it though Orbicularis oris Muscles That Move Vertebral Column anterior superficial posterior deep Rectus abdominus Internal oblique External oblique Transverse abdominus Muscles That Move Vertebral Column deepest muscles just pics memorize pic Muscles of Respiration External intercostal Diaphragm Internal intercostal Let s Practice Use models to identify muscles listed on tables 2 3 and 4 Muscles That Move Pectoral Girdle Pectoralis minor Levator scapulae Rhomboid minor Rhomboid major Trapezius Muscles That Move Arm Supraspinatus Deltoid Pectoralis major Infraspinatus Teres major Latissimus dorsi Muscles That Move Forearm Biceps brachii Brachialis Brachioradialis Triceps Brachii Posterior View Muscles That Move Hand Flexor carpi ulnaris Palmaris longus Flexor carpi radialis Flexor digitorum superficialis Left Anterior Superficial Right Anterior Superficial Muscles That Move Hand Flexor digitorum superficialis Flexor digitorum profundus Left Anterior Deep Right Anterior Deep Muscles That Move Hand Extensor carpi radialis longus Extensor digitorum Extensor carpi ulnaris Extensor digiti minimi Abductor pollicis longus Left Posterior Superficial Right Posterior Superficial Let s Practice Use models to identify muscles listed in tables 5 6 7 and 8 Muscles That Move Thigh Psoas major Gluteus maximus Gluteus medius Iliacus Left Anterior View