2. 1 Smooth muscle Contraction Spindle Shaped Central nuclei Lack Striations, transverse tubules, and lack well developed sacroplasmic reticulum Actin and myosin thin and randomly distributed Multi-unit-Separate units »Muscle of iris and blood vessels Visceral-Sheets of spindle cells »Respond as a single unit »Rhythmicity- spontaneous »peristalsis

3. 2 Internal organs- outer longitudinal Inner circular Contraction Impulses travel across the membrane- Calcium diffuses into the cell from the extracellular fluid. Calcium binds to a protein calmodulin-activating contraction. Nt- Ach and Norepi, stimulates/ inhibits contractions altering degrees of contraction. Smooth- slow and longer contraction

4. 3 Terms Origin Insertion Prime mover-Agonist Assist a prime mover-Synergists Antagonist- movement in the opposite direction or resist a prime mover,

5. 4 Skeletal Muscle Actions origin – immovable end insertion – movable end prime mover (agonist) – primarily responsible for movement synergists – assist prime mover antagonist – resist prime mover’s action and cause movement in the opposite direction

6. 5 Muscular Tissue Three Types of Muscle Tissues Skeletal Muscle usually attached to bones under conscious control striated Smooth Muscle walls of most viscera, blood vessels, skin not under conscious control not striated Cardiac Muscle wall of heart not under conscious control striated

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8. 7 Smooth Muscle Fibers Compared to skeletal muscle fibers shorter single nucleus elongated with tapering ends myofilaments randomly organized no striations lack transverse tubules sarcoplasmic reticula not well developed

9. 8 Cardiac Muscle only in the heart muscle fibers joined together by intercalated discs fibers branch network of fibers contracts as a unit self-exciting and rhythmic longer refractory period than skeletal muscle

10. 9 Muscles of Facial Expression-CNVII Orbicularis oculi- blinking/closes eyelids Orbicularis oris-closes lips/protrudes lips-kissing Buccinator-compresses cheeks as in blowing air Zygomaticus-raises corner of mouth/smiling Platysma-pouting/draws mouth downward & elevates skin Frontalis-elevates eyebrows & creases skin

11. 10

12. 11 Muscles of Mastication-CNV 3 Masseter-elevates mandible Temporalis-elevates mandible Pterygoid –Medial-elevates and moves it from side to side –Lateral-depresses and protracts

13. 12

14. 13 Muscles of Head and Vertebra Paired muscles- flex, extend, and rotate the head and hold the torso erect. Sternocleidomastoid-flex and rotates Extend and rotate –Splenius capitis –Semispinalis capitis –Erector spinae

15. 14 Muscle of the Pectoral Girdle Trapezius- raises scapula and shoulders, elevates clavicle, extends neck and head Serratus Anterior -pulls scapula forward and downward, used when pushing something. –Damage to the long thoracic nerve-results in winged scapula Rhomboids-retracts, elevates, and rotates Levator Scapula-elevates scapula Pectoralis minor- pulls scapula in forward and downward, raise ribs in forceful inhalation

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19. 18 Muscles That Move the Arm Flexors –Coracobrachialis –Pectoralis major- also adducts arm Extensors –Teres Major – Latissimus dorsi- also adducts arm (swimmer muscle) Abductors –Deltoid – most prominent muscle of the shoulder-axillary nerve-fracture to the neck of humerus-unable to abduct the arm –Supraspinatus Rotators cuff muscles –Subscapularis –Infraspinatus –Teres minor –Supraspinatus

20. 19 Movement of Forearm Biceps brachii-flexes and laterally rotates elbow Brachialis- strongest flexor of elbow Brachioradialis-aids in flexing Triceps- opposes-extends elbow

21. 20 Muscle of the Abdominal area Compress the abdominal cavity and increases pressure, used during forceful exhalation or defecation Rectus abdominis-six pack External oblique-fibers runs downward to pelvic girdle Internal oblique-fibers run upward to lower ribs Transversus abnominis- deepest layer-runs horizontally across Linea alba- connective tissue band that runs from xiphoid to symphysis pubis

22. 21

23. 22

24. 23 Transversus abdnominis

25. 24 Muscles of the Thigh Anterior group- primary flexors of thigh –Psoas –iliacus Posterior group- extends the thigh –Gluteus muscles- maximus-the largest muscle in the body –Tensor fasciae latae-extends from ilium to the iliotibial tract- abducts, rotates, and flexes Adductors –Pectineus-flexes –Adductor brevis, longus, magnus-flex and rotate –Gracilis- straplike band from the pubic bone to tibia

26. 25

27. 26 Pectineus

28. 27 Gluteus Muscle

29. 28 Quadriceps Femoris group Extensor Extends leg at knee Rectus femoris Vastus lateralis Vastus medialis Vastus intermedius

30. 29 Flexors of knee Hamstring Muscles Biceps femoris Semimembranosus Semitendinosus Sartorius-strap like that passes obliquely across the front of thigh- abducts and rotates laterally

31. 30 Semitendinosus Semimembranosus

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