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Home , Hamate bone, Hypothenar eminence, Muscles of the hand, Thenar eminence, Thorax, Upper limb

MUSCLES OF THE

UPPER

The muscles that act on the fall into four groups: those that stabilize the pectoral girdle, those that move the , those that move the , and those that move the , , and .

Muscles Stabilizing Pectoral Girdle (Marieb / Hoehn – Chapter 10; Pgs. 346 – 349; Figure 1)

MUSCLE: ORIGIN: INSERTION: INNERVATION: ACTION:

ANTERIOR :

anterior surface protracts & depresses * pectoral of 3 – 5 of scapula

medial border rotates scapula Serratus anterior* ribs 1 – 8 long thoracic of scapula laterally

inferior surface stabilizes / depresses Subclavius* 1 ------of pectoral girdle

POSTERIOR THORAX: occipital / / spine of stabilizes / elevates / * spinous processes scapula; lateral third retracts / rotates (cranial nerve XI) of C7 – T12 of clavicle scapula

transverse processes upper medial border elevates / adducts Levator scapulae* of C1 – C4 of scapula scapula

Rhomboids* spinous processes medial border adducts / rotates dorsal scapular nerve (major / minor) of C7 – T5 of scapula scapula

* Need to be familiar with on both ADAM and the cadaver

Figure 1: Muscles stabilizing pectoral girdle, posterior and anterior views

2 BI 334 – Advanced Human and Physiology Western Oregon University Muscles Moving Arm (Marieb / Hoehn – Chapter 10; Pgs. 350 – 352; Figure 2)

MUSCLE: ORIGIN: INSERTION: INNERVATION: ACTION:

intertubercular sulcus / / clavicle / flexes / medially rotates / * pectoral nerves ribs 1 – 6 adducts arm of acromion / spine of Deltoid* scapula; lateral third abducts arm of humerus of clavicle spinous processes of intertubercular groove Latissimus dorsi* T – L / ribs 9 – 12 / extends / adducts arm 7 5 of humerus iliac crest of os coxa

subscapular fossa Subscapularis* subscapular nerves rotates arm medially of scapula of humerus

supraspinous fossa greater tubercle Supraspinatus* abducts arm of scapula of humerus

infraspinous fossa greater tubercle Infraspinatus* suprascapular nerve rotates arm laterally of scapula of humerus

lateral border greater tubercle Teres minor* subscapular nerves rotates arm laterally of scapula of humerus

inferior border lesser tubercle rotates medially / Teres major* subscapular nerves of scapula of humerus adducts arm

coracoid process medial shaft musculocutaneous Coracobrachialis* flexes / adducts arm of scapula of humerus nerve

* Need to be familiar with on both ADAM and the human cadaver

3 BI 334 – Advanced Human Anatomy and Physiology Western Oregon University

Figure 2: Muscles that move the arm, anterior and posterior views (note: subscapularis not shown)

4 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: below glenoid cavity of process brachii* scapula / posterior shaft extends forearm of of humerus

lateral epicondyle olecranon process Anconeus radial nerve extends forearm of humerus of ulna

ANTERIOR MUSCLES: coracoid process / musculocutaneous brachii* above glenoid cavity flexes forearm of nerve of scapula

anterior coronoid process musculocutaneous Brachialis* flexes forearm of distal humerus of ulna nerve

lateral epicondyle styloid process * radial nerve flexes forearm of ulna (radius)

* Need to be familiar with on both ADAM and the human cadaver

5 BI 334 – Advanced Human Anatomy and Physiology Western Oregon University

Figure 3: Muscles that move the forearm, anterior and posterior views

6 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: medial epicondyle of Pronator teres* humerus; coronoid lateral shaft of radius pronates forearm process of ulna

medial epicondyle Flexor carpi radialis* metacarpals 2 – 3 median nerve flexes / abducts wrist of humerus

medial epicondyle tenses of palm during Palmaris longus median nerve of humerus hand movement

medial epicondyle pisiform / Flexor carpi ulnaris* of humerus; olecranon flexes / adducts wrist of carpals process of ulna

Flexor digitorum medial epicondyle of humerus; coronoid process middle phalanges 2 – 5 median nerve flexes wrist / fingers superficialis* of ulna ; shaft of radius

DEEP MUSCLES: coronoid process / Flexor digitorum anteriomedial surface distal phalanges 2 – 5 ulnar / median nerves flexes wrist / fingers profundus* of ulna

anterior surface distal phalanx Flexor pollicis longus median nerve flexes of radius of thumb

distal surface of distal surface of Pronator quadratus median nerve pronates forearm anterior ulna anterior radius

* Need to be familiar with on both ADAM and the human cadaver

7 BI 334 – Advanced Human Anatomy and Physiology Western Oregon University

Figure 4: Anterior muscles that move the wrist, hand, and fingers

8 BI 334 – Advanced Human Anatomy and Physiology Western Oregon University

Muscles Moving the Wrist, Hand, and Fingers - Posterior (Marieb / Hoehn – Chapter 10; Pgs. 356 – 357; Figure 5)

MUSCLE: ORIGIN: INSERTION: INNERVATION: ACTION:

SUPERFICIAL MUSCLES: Extensor carpi lateral epicondyle radialis* metacarpals 2 – 3 radial nerve extends / abducts wrist of humerus (longus / brevis)

lateral epicondyle Extensor digitorum* distal phalanges 2 – 5 radial nerve extends fingers of humerus

Extensor carpi lateral epicondyle metacarpal 5 radial nerve extends / adducts wrist ulnaris* of humerus

DEEP MUSCLES: lateral epicondyle of proximal end Supinator humerus; proximal end radial nerve supinates forearm of radius of ulna

Abductor pollicis posterior surface metacarpal 1 / abducts / extends radial nerve longus* of radius and ulna of carpals thumb

Extensor pollicis* dorsal shaft proximal / distal radial nerve extends thumb (longus / brevis) of radius / ulna ends of phalange 1

posterior surface Extensor indicis phalange 2 radial nerve extends index of distal ulna

* Need to be familiar with on both ADAM and the human cadaver

9 BI 334 – Advanced Human Anatomy and Physiology Western Oregon University

Figure 5: Posterior muscles that move the wrist, hand, and fingers

10 BI 334 – Advanced Human Anatomy and Physiology Western Oregon University

Out-of-Class Assignment: Intrinsic

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 (ball of thumb), the (ball of the ), 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 .

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

11 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

12 BI 334 – Advanced Human Anatomy and Physiology Western Oregon University

13 BI 334 – Advanced Human Anatomy and Physiology Western Oregon University