Muscles of the Upper Limb: Stabilizers and Movers of the Shoulder and Arm, Lecture notes of Aviation

Download Muscles of the Upper Limb: Stabilizers and Movers of the Shoulder and Arm and more Lecture notes Aviation in PDF only on Docsity! MUSCLES OF THE APPENDICULAR SKELETON UPPER LIMB The muscles that act on the upper limb fall into four groups: those that stabilize the pectoral girdle, those that move the arm, those that move the forearm, and those that move the wrist, hand, and fingers. Muscles Stabilizing Pectoral Girdle (Marieb / Hoehn – Chapter 10; Pgs. 346 – 349; Figure 1) MUSCLE: ORIGIN: INSERTION: INNERVATION: ACTION: ANTERIOR THORAX: Pectoralis minor* anterior surface of ribs 3 – 5 coracoid process of scapula pectoral nerves protracts & depresses scapula Serratus anterior* ribs 1 – 8 medial border of scapula long thoracic nerve rotates scapula laterally Subclavius* rib 1 inferior surface of clavicle --------------- stabilizes / depresses pectoral girdle POSTERIOR THORAX: Trapezius* occipital bone / spinous processes of C7 – T12 acromion / spine of scapula; lateral third of clavicle accessory nerve (cranial nerve XI) stabilizes / elevates / retracts / rotates scapula Levator scapulae* transverse processes of C1 – C4 upper medial border of scapula dorsal scapular nerve elevates / adducts scapula Rhomboids* (major / minor) spinous processes of C7 – T5 medial border of scapula dorsal scapular nerve adducts / rotates scapula * Need to be familiar with on both ADAM and the human cadaver 2 BI 334 – Advanced Human Anatomy and Physiology Western Oregon University Figure 1: Muscles stabilizing pectoral girdle, posterior and anterior views 5 BI 334 – Advanced Human Anatomy and Physiology Western Oregon University Muscles Moving Forearm (Marieb / Hoehn – Chapter 10; Pgs. 352 – 353; Figure 3) MUSCLE: ORIGIN: INSERTION: INNERVATION: ACTION: POSTERIOR MUSCLES: Triceps brachii* below glenoid cavity of scapula / posterior shaft of humerus olecranon process of ulna radial nerve extends forearm Anconeus lateral epicondyle of humerus olecranon process of ulna radial nerve extends forearm ANTERIOR MUSCLES: Biceps brachii* coracoid process / above glenoid cavity of scapula radial tuberosity of radius musculocutaneous nerve flexes forearm Brachialis* anterior face of distal humerus coronoid process of ulna musculocutaneous nerve flexes forearm Brachioradialis* lateral epicondyle of ulna styloid process (radius) radial nerve flexes forearm * Need to be familiar with on both ADAM and the human cadaver 6 BI 334 – Advanced Human Anatomy and Physiology Western Oregon University Figure 3: Muscles that move the forearm, anterior and posterior views 7 BI 334 – Advanced Human Anatomy and Physiology Western Oregon University Muscles Moving Wrist, Hand, and Fingers - Anterior (Marieb / Hoehn – Chapter 10; Pgs. 354 – 356; Figure 4) MUSCLE: ORIGIN: INSERTION: INNERVATION: ACTION: SUPERFICIAL MUSCLES: Pronator teres* medial epicondyle of humerus; coronoid process of ulna lateral shaft of radius median nerve pronates forearm Flexor carpi radialis* medial epicondyle of humerus metacarpals 2 – 3 median nerve flexes / abducts wrist Palmaris longus medial epicondyle of humerus palmar aponeurosis median nerve tenses skin of palm during hand movement Flexor carpi ulnaris* medial epicondyle of humerus; olecranon process of ulna pisiform / hamate bone of carpals ulnar nerve flexes / adducts wrist Flexor digitorum superficialis* medial epicondyle of humerus; coronoid process of ulna ; shaft of radius middle phalanges 2 – 5 median nerve flexes wrist / fingers DEEP MUSCLES: Flexor digitorum profundus* coronoid process / anteriomedial surface of ulna distal phalanges 2 – 5 ulnar / median nerves flexes wrist / fingers Flexor pollicis longus anterior surface of radius distal phalanx of thumb median nerve flexes thumb Pronator quadratus distal surface of anterior ulna distal surface of anterior radius median nerve pronates forearm * Need to be familiar with on both ADAM and the human cadaver 10 BI 334 – Advanced Human Anatomy and Physiology Western Oregon University Figure 5: Posterior muscles that move the wrist, hand, and fingers 11 BI 334 – Advanced Human Anatomy and Physiology Western Oregon University Out-of-Class Assignment: Intrinsic Muscles of the Hand Intrinsic muscles are found only in the palm of the hand (none on the dorsal surface). These small, relatively weak muscles control the precise movements of the metacarpals and the fingers, leaving the powerful movements of the fingers (e.g., power grip) to the forearm muscles. The intrinsic muscles of the palm are divided into three groups: those in the thenar eminence (ball of thumb), the hypothenar eminence (ball of the little finger), and the midpalm. The thenar and hypothenar eminence groups are responsible for flexing, abducting, and opposing the respective digits. The midpalm muscles extend the fingers at the interphalangeal joints. Below is a table listing the individual muscles in each functional group. For each muscle, fill in the appropriate origin, insertion, innervation, and action and then correctly label the muscle on the associated figure(s). This exercise is to introduce you to these muscles; you will not be responsible for these groups of muscles for the practical exam. MUSCLE: ORIGIN: INSERTION: INNERVATION: ACTION: THENAR MUSCLES: Abductor pollicis brevis Flexor pollicis brevis Opponens pollicis Adductor pollicis 12 BI 334 – Advanced Human Anatomy and Physiology Western Oregon University MUSCLE: ORIGIN: INSERTION: INNERVATION: ACTION: HYPOTHENAR MUSCLES: Abductor digiti minimi Flexor digiti minimi brevis Opponens digiti minimi MIDPALMAR MUSCLES: Lumbricals Palmar interossei Dorsal interossei