AP Unit 4 Muscular System Lecture Packet PDF

Unit 4: Lecture Packet The Muscular System Accelerated Anatomy & Physiology Adlai E. Stevenson High School Name: ___________________________ Period: ____  Topic 1: Structure of Muscle Tissue Review of Skeletal Mu...

Unit 4: Lecture Packet The Muscular System Accelerated Anatomy & Physiology Adlai E. Stevenson High School Name: ___________________________ Period: ____  Topic 1: Structure of Muscle Tissue Review of Skeletal Muscles Skeletal Smooth Cardiac movement at joints, movement of viscera pumping action of the maintenance of posture heart rod shaped spindle shaped branched striated no striations striated no discs present no discs present intercalated discs voluntary involuntary involuntary Muscles contain many different types of tissues; muscle tissue, nervous tissue, connective tissues, blood Tendon – attaches muscle to bone Epimysium – layer of connective tissue that surrounds muscle Fascicle – bundle of skeletal muscle (sing: fasciculi) Perimysium – surrounds the fascicles Muscle fiber – a single muscle cell contracts – stimulated relaxes – no stimulation Endomysium – surrounds a muscle fiber 1: LP Muscles contract due to filaments that slide past one another. This illustration shows the two filaments that work within a muscle cell. Sarcolemma – muscle cell membrane, (under endomysium); cytoplasm within a muscle cell is called sarcoplasm Myofibril – contractile fibers within muscle cells Myofilaments – protein filaments that slide past each other to produce muscle contraction actin (thin); myosin (thick) Remember, skeletal muscle is striated Dark A Bands – where myosin and actin filaments overlap Light I Bands – contains just thin actin filaments Z line – hold the thin actin filaments in place M line – hold the thick myosin filaments in place H zone – contains only myosin (thick) filaments Sarcomere – contractile unit of muscle; myosin filaments pull actin filaments closer to center (H zone) IMPORTANT NOTE muscle filaments do not shorten during contraction; they slide past each other. 2: LP  Topic 2: Body Movements Learning Target IV. I can describe the various physiological processes for a given body system. f. I understand the relationship between different joint types and body movement. Flexion bending parts at a joint so that the angle between them decreases and the parts come closer together Extension straightening parts at a joint so that the angle between them increases and the parts move farther apart Dorsiflexion movement at the ankle that brings foot towards the shin o walking on your heels Plantar flexion movement at the ankle that brings the foot farther from the shin o walking on your toes Hyperextension extension of the parts at a joint beyond anatomical position may result in injury Abduction moving a part away from the midline Adduction moving a part towards (adding it to) the midline Rotation moving a body part around an axis Circumduction moving a body part so its end follows a circular path 3: LP Supination turning the hand so that the palm is upward or facing anteriorly o holding a bowl of soup Pronation turning the hand so that the palm is downward or facing posteriorly Eversion turning the foot so the plantar surface (sole) faces laterally Inversion turning the foot so the plantar surface faces medially Protraction moving a body part forward Retraction moving a body part backward Elevation raising a body part Depression lowering a body part 4: LP  Topic 3: Skeletal Muscles (Part 1) - Intro, Roles & Naming of Muscles Interactions of Muscles: Closing the jaw or Holding a glass of water Prime Movers (Agonist) When several muscles are contracting at once, this is the major muscle responsible for the movement Synergists- Help prime movers by reducing undesirable, unnecessary movement Fixators- Specialized synergists that hold bone still Agonist (Prime Movers) Antagonists- Muscle that opposes or reverses a movement 5: LP Naming Muscles 1. Direction of muscle fibers ○ Rectus: straight ○ Oblique: at an angle 2. Size-Maximus, medius, minimus ○ Rectus: straight ○ Oblique: at an angle 3. Location- Frontalis, Temporalis 4. Number of origins - biceps, triceps ○ Origin: immovable/less movable point of attachment ○ Insertion: movable point of attachment 5. Location of muscle’s origin and insertion - sterno- cleido- mastoid 6. Shape of the muscle- Deltoid = triangle 7. Action of the muscle- flexor, extensor, adductor 6: LP Topic 4: Skeletal Muscles (Part 2) - Muscles of the face 7: LP Topic 5: Skeletal Muscles (Part 3) Muscles of the Body & Arms 8: LP Topic 6: Skeletal Muscles (Part 4) Muscles of the Legs 9: LP