CHAPTER 11 MUSCLE Part 1

CHAPTER 10 MUSCLE – part 1

muscles move bones Muscles provide the force to move a body part by pulling a bone !

interactions of muscles • prime mover = agonist – the main muscle for a specific action • synergist – helps the prime mover – same side of joint – fixator - hold bone in place as agonist acts • antagonist – opposite action to agonist – opposite side of joint

types of muscle contractions • isotonic muscle length changes • isometric muscle length doesn’t change

arrangement of fascicles • parallel • convergent • pennate • circular • note: seeing a muscle’s fibers tells you its action . muscles contract along the axis of the fascicles.

muscle names • name includes clues of location and action : • biceps brachii arm , 2 heads • biceps femoris thigh , 2 heads • extensor carpi radialis extends the wrist on side of the radius • brachioradialis attaches arm (humerus) to radius • orbicularis oris circular , mouth • gluteus maximus gluteal area ; biggest muscle • spelling counts – be careful of endings -is or -us

axial musculature • O and I on axial skeleton • move the head, neck, trunk, rib cage • maintain posture • facial movement • mastication and tongue • swallowing • neck • back • breathing • abdominal wall • pelvic floor appendicular muscles • insert on appendicular skeleton • move upper and lower extremity • stabilize pectoral or pelvic girdle • scapula • shoulder • elbow • forearm and hand • hip • knee • leg and foot what you need to know : • name the muscle • action • synergists • antagonists • origin main attachments • insertion main attachments

actions = ROM • flexion / extension • lateral flexion (right, left) • rotation (internal, external) • abduct / adduct • dorsiflex / plantarflex • supination / pronation • inversion / eversion • elevation / depression • protraction / retraction muscle actions • muscle act by shortening their fibers • they pull bones closer to each other • action based on : • side of joint it crosses • direction of its fibers • insertion moves toward origin what action ? • anterior elbow • posterior elbow • anterior wrist , hand • posterior wrist , hand • anterior shoulder • posterior shoulder • medial shoulder • lateral shoulder • anterior neck • posterior torso • above scapula

elbow – anterior • A: ______• biceps brachii – O: short head: coracoid process long head: glenoid cavity (through intertubercular groove) – I: radial tuberosity • brachialis – O: distal humerus (anterior) – I: ulna , coronoid process • brachioradialis – O: distal humerus , lateral – I: radius styloid

elbow – posterior • A: ______• triceps brachii – O: long head infraglenoid tubercle lateral head lateral humerus medial head posterior humerus – I: olecranon process

• anconeus – O: lateral epicondyle of humerus – I: olecranon process shoulder - anterior • A: ______• biceps – O: glenoid cavity (superior) ; coracoid – I: radial tuberosity • coracobrachialis – O: coracoid process – I: humerus shaft

• pectoralis major – O: sternum , clavicle, ribs – I: greater tubercle (humerus)

shoulder - posterior • A: ______• triceps – O: long head infraglenoid tubercle – I: olecranon process • latissimus dorsi – O: L/S and lower T/S vertebrae – I: intertubercular groove (through axilla)

shoulder - lateral • A: ______• deltoid – O: acromion , scapular spine , clavicle – I: deltoid tuberosity

• supraspinatus – O: supraspinous fossa – I: greater tubercle (superior)

shoulder - medial • A: ______• pectoralis major – O: sternum , clavicle, ribs – I: greater tubercle (humerus)

• latissimus dorsi – O: L/S and lower T/S vertebrae – I: intertubercular groove (posterior)

• shoulder rotators

shoulder - rotators • infraspinatus A: ______– O: infraspinous fossa – I: greater tubercle (posterior) • teres minor A: ______– O: scapula , lateral border – I: greater tubercle (posterior) • teres major A: ______– O: scapula , posterior / inferior – I: lesser tubercle • subscapularis A: ______– O: subscapular fossa – I: lesser tubercle (anterior)

rotator cuff • action : stabilize shoulder ; rotate humerus • supraspinatus • infraspinatus • teres minor • subscapularis

radius - ulna • posterior – supinator A: ______• O: lateral epicondyle , humerus proximal ulna • I: radius (posterior) • anterior A: ______– pronator - teres quadratus • O: ulna • I: radius (anterior)

forearm - anterior • A: ______– O: medial epicondyle ulna , anterior – I: carpals , metacarpals, phalanges • flexor carpi radialis • palmaris longus • flexor carpi ulnaris • flexor digitorum superficialis • flexor digitorum profundus • flexor pollicis longus

forearm - posterior • A: ______– O: lateral epicondyle ulna and radius, posterior – I: carpals , metacarpals, phalanges • extensor carpi radialis longus • extensor carpi radialis brevis • extensor digitorum • extensor carpi ulnaris • extensor pollicis longus • extensor pollicis brevis • abductor pollicis longus • extensor indicis • extensor digiti minimi hand • know these terms: – pollicis – indicis – digiti – digiti minimi – opponens – abductor, adductor, flexor, extensor

• locate muscles – combinations of these terms

hand • thenar emminence : – abductor pollicis brevis – opponens pollicis – flexor pollicis brevis – adductor pollicis • hypothenar emminence : – abductor digit minimi – flexor digiti minimi brevis – opponens digiti minimi – palmaris brevis • intrinsic muscles – interossei adduct , abduct – lumbricals flex/extend interphalangeal joints

what the action? • abductor pollicis longus, brevis • adductor pollicis • extensor pollicis longus, brevis • flexor pollicis • opponens pollicis • extensor indicis • abductor digiti minini • opponens digiti minimi • flexor digit minimi • extensor digiti minimi scapula • trapezius , upper – O: occiput , cervical vert, ligamentum nuchae – I: acromion, scapular spine, clavicle – A:

• trapezius, middle and lower – O: thoracic vertebrae – I: scapular spine – A: depress scapula scapula • levator scapulae – O: TP’s C1 – C4 – I: medial / superior scapula – A:

• rhomboids major , minor – O: SP’s C7 – T5 – I: medial border scapula – A: scapula • pectoralis minor – O: ribs 3-5 (anterior) – I: coracoid process – A: • serratus anterior – O: ribs 1-8 – I: scapula , anterior – A:

• http://bioweb.uwlax.edu/aplab/Table_of_Contents/table_of_contents.html • http://www.mhhe.com/biosci/ap/cat_dissect/cat_demo/muscular_system/muscle_index.html