O RGANIZATION OF S KELETAL M USCLE

S KELETAL M USCLE O RGANIZATION Connective Tissue Coverings Skeletal muscles are attached to tendons which attach the muscle to bone Belly : Thicker part of muscle Epimysium : connective tissue layer that covers the muscle Separates muscles from other structures/organs Perimysium : Layer underneath the epimysium Separates muscles into individual bundles Endomysium : Layer underneath the perimysium Surrounds each individual muscle fiber

S KELETAL M USCLE O RGANIZATION

S TRUCTURE OF A S KELETAL M USCLE F IBER Individual Muscle Fiber consists of: (outside to inside) Outside of muscle fiber 1. Sarcolemma : cell membrane of muscle fiber 2. Sarcoplasm : cytoplasm of muscle fiber 3. Transverse Tubules or T-Tubules: connections from the sarcolemma to interior of muscle fiber for connection Inside muscle fiber 1. Myofibrils : proteins that run the length of each fiber, surrounded by Sarcoplasmic Reticulum 1. S. R. stores Ca2+ ions which dictates muscle contraction

S TRUCTURE OF A S KELETAL M USCLE F IBER Myofibril Components: Several Sarcomeres made up of: Actin : Thin Filaments, bundles with globular sections that fit into the binding sites on actin Myosin : Thick Filaments, has binding sites to which actin attaches to during contraction

M USCLE C ONTRACTION T-tubules are stimulated from the nervous system T-tubules release Ca2+ ions The thin filaments/actin then are pulled along the thick filaments/myosin in place of where the Ca2+ ions were

R IGOR M ORTIS After death, ion pumps stop functioning  calcium builds up in the sarcoplasm causing a fixed muscular contraction

M USCLE P AIN Soreness after a workout Stretching the muscle tissue farther than usual Small microscopic tears to an individual muscle fiber Skeletal muscle tissue is multinucleated + many neuromuscular junctions  you mind sends signals when you are injured

S KELETAL MUSCLE IDENTIFICATION Muscular system can be divided into 2 groups: 1. Axial Muscles (60 %) 2. Appendicular Muscles (40%)

N EUROMUSCULAR J UNCTION Each skeletal muscle is controlled by a nerve cell called a motor neuron Where the motor neuron and muscle fiber meet = Neuromuscular Junction

A XIAL M USCLES Muscles that position the head, spinal column, and move the rib cage. Divided into 4 groups based on location and function: 1. Muscles of the head and neck 2. Muscles of the vertebral column 3. Oblique and rectus muscles 4. Muscles of the pelvic

A XIAL M USCLES Muscles of the Skull Orbicularis oris Orbicularis Oculi Nasalis Zygomaticus Major Zygomaticus Minor Frontalis

A XIAL M USCLES Muscles of the Skull continued… Platysma Buccinator Temporalis Occipitalis Masseter Sternocleidomastoid

A XIAL M USCLES Muscles of the Back Trapezius Latissimus Dorsi

A XIAL M USCLES Muscles of the Oblique Pectoralis major Serratus Anterior Rectus Abdominis External abdominal oblique

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A PPENDICULAR M USCLES Muscles that support the pectoral and pelvic girdles, and the limbs. Separated into 2 major groups: 1. Muscles of shoulders and upper limbs 2. Muscles of pelvis and lower limbs

A PPENDICULAR M USCLES Muscles of Pectoral girdle: Trapezius Rhomboid Serratus anterior Subcavius Pectoralis minor

A PPENDICULAR M USCLES Muscles that move the arm: Deltoid Supraspinatus Subscapularis Infraspinatus Coracobrachialis Pectoralis major Latissimus dorsi

A PPENDICULAR M USCLES Muscles of the arm: Biceps brachii Triceps brachii Brachialis Brachioradialis Flexor carpi ulnaris Flexor carpid radialis Palmaris longus Extensor carpi radialis Extensor carpi ulnaris

A PPENDICULAR M USCLES Muscles of the Pelvic Girdle: Gluteus maximus Tensor fasciae latae Gluteus medius Gluteus minimus Adductors Iliopsoas

A PPENDICULAR M USCLES Muscles that move the lower limb: Biceps femoris Semimembranosus Sartorius Popliteus Rectus femoris semitendinosus

A PPENDICULAR M USCLES Muscles of the lower limb: Gastrocnemius Soleus Fibularis Tibialis posterior Tibialis anterior Extensor digitorum longum Calcaneal tendon