Gross Anatomy Upper Limb

Trapezius: origin

-Medial third of superior nuchal line -Ligamentum nuchae -Tips of spines of C7, all thoracic vertebrae, supraspinous ligaments

Trapezius: insertion

-Lateral third of clavicle -Medial aspect of acromion and superior margin of crest of the spine of scapula -Medial aspect of spine of scapula

Trapezius: innervation

-Spinal Accessory nerve (CN XI) -Sensory branches from cervical plexus- C3 & C4

Trapezius: action

Scapula Rotation so glenoid cavity faces superiorly -Upper (elevates acromion) -Middle (retracts scapula) -Lower (Depresses medial end of scapula spine)

Latissimus dorsi: origin

-Tips of lower six thoracic spines (T7-T12) -Thoracolumbar fascia -Outer lip of iliac crest -Lower 3-4 ribs -Fleshy slip from back of interior angle of scapula

Latissimus dorsi: insertion

Floor of intertubercular sulcus of the humerus

Latissimus dorsi: innervation

Thoracodorsal nerve

Latissimus dorsi: action

-Adduction (Humerus) -Medial Rotation (Humerus) -Extension (Humerus)

Levator scapulae: innervation

-Dorsal scapular nerve (ventral ramus of C5) -C3 and C4

Rhomboideus major and minor: innervation

Dorsal scapular nerve (ventral ramus of C5)

Serratus Posterior superior: action

Respiration

Serratus posterior inferior: action

Respiration

Erector spinae: innervation

Dorsal rami of spinal nerves

Erector spinae: action

-Acting bilaterally- extend vertebral column & head -Acting unilaterally- bend vertebral column laterally

Pectoralis major: origin

-Clavicular head: medial half of anterior portion -Sternocostal Head: sternum anterior surface, upper 6 costal ribs/cartilage

Pectoralis major: insertion

-Flat bilaminar tendon to the crest of the greater tubercle of the humerus (Lateral lip of the Bicipital groove)

Pectoralis major: innervation

Medial and Lateral Pectoral nerves

Pectoralis major: action

-Adduction -Medial Rotation (Humerus) -Flexion of the arm at the shoulder joint

Pectoralis minor: origin

Arises from ribs 3, 4, 5 (close to costal cartilage)

Pectoralis minor: insertion

Medial border and upper surface of coracoid process

Pectoralis minor: innervation

Medial and Lateral Pectoral Nerves (from the medial and lateral cords)

Pectoralis minor: action

-Stabalizes scapula (pulls it inferiorly and anteriorly against thoracic wall) -Depresses and protracts the scapula

Supraspinatus: origin

Supraspinous Fossa

Supraspinatus: insertion

Upper facet of greater tubercle of humerus

Supraspinatus: innervation

Suprascapular Nerve (arises from upper trunk C5, 6)

Supraspinatus: action

1st 15 degrees of Abduction (then deltoid takes over)

Infraspinatus: origin

Infraspinous Fossa

Infraspinatus: insertion

Middle facet of the greater tubercle of humerus

Infraspinatus: innervation

Suprascapular Nerve (arises from upper trunk C5, 6)

Infraspinatus: action

Powerful lateral rotator

Teres minor: origin

lateral border of scapula

Teres minor: insertion

lower facet on greater tubercle of humerus

Teres minor: innervation

Axillary Nerve

Teres minor: action

Laterally rotates arm

Teres major: origin

Lateral border & inferior angle of scapula

Teres major: insertion

medial lip of bicipital groove of humerus

Teres major: innervation

Lower Subscapular Nerve

Teres major: action

Adducts and medially rotates the arm

Triceps brachii, long head: origin

Infraglenoid tubercle

Triceps brachii, lateral head: origin

Oblique line on posterior surface of humerus

Triceps brachii, medial head: origin

Posterior surface of humerus below the radial groove

Triceps brachii, all heads: insertion

Olecranon process (on ulna)

Triceps brachii, all heads: innervation

-Radial nerve. -Long head of triceps gets its nerve supply while the radial nerve is in the axilla.

Coracobrachialis: origin

Coracoid process

Coracobrachialis: insertion

middle part of the medial border of humerus

Coracobrachialis: innervation

Musculocutaneous nerve

Biceps brachii, long head: origin

Supraglenoid tubercle

Biceps brachii, short head: origin

coracoid process of scapula

Biceps brachii, all heads: insertion

posteromedial aspect of radial tuberosity

Biceps brachii, all heads: action

Flexion of arm/forearm and supination of flexed elbow

Brachialis: origin

lower half of front of humerus

Brachialis: insertion

anterior surface of coronoid process and tuberosity of ulna

Brachialis: innervation

Musculocutaneous nerve & radial nerve

Brachialis: action

Flexor of forearm

Pronator teres: origin

medial epicondyle of humerus

Pronator teres: innervation

median nerve

Pronator teres: action

flexor of forearm

Palmaris longus: origin

medial epicondyle of humerus

Palmaris longus: innervation

median nerve

Palmaris longus: action

flexor of forearm

Flexor carpi radialis: origin

medial epicondyle of humerus

Flexor carpi radialis: innervation

median nerve

Flexor carpi radialis: action

flexor of forearm

Flexor carpi ulnaris: origin

medial epicondyle of humerus

Flexor carpi ulnaris: innervation

ulnar nerve

Flexor carpi ulnaris: action

flexor of forearm

Brachioradialis: origin

proximal two third of the lateral supracondylar ridge of the humerus

Brachioradialis: insertion

distal end of radius

Brachioradialis: innervation

Radial nerve

Brachioradialis: action

flexor of forearm

Flexor digitorum superficialis: origin

-Humeral head: Medial epicondyle of the humerus -Radial head: Superior half of anterior border of radius

Flexor digitorum superficialis: insertion

Middle phalanges of medial four digits

Flexor digitorum superficialis: action

Flexes middle phalanges and metacarpophalangeal joint

Flexor digitorum superficialis: innervation

median nerve

Flexor digitorum profundus: origin

Proximal 3/4 of medial and anterior surfaces of ulna and interosseous membrane

Flexor digitorum profundus: insertion

Bases of distal phalanx of medial four fingers

Flexor digitorum profundus: innervation

Medial 1/2 by the ulnar nerve & lateral 1/2 by anterior interosseous nerve

Flexor digitorum profundus: action

Flexes distal phalanges in all four fingers & flexes metacarpophalangeal joints

Flexor pollicis longus: origin

Anterior surface of the radius and interosseous membrane

Flexor pollicis longus: insertion

Base of the distal phalanx of the thumb

Flexor pollicis longus: innervation

Anterior interosseous nerve

Flexor pollicis longus: action

Flexes phalanges of the first digit

Pronator quadratus: origin

Distal quarter of anterior surface of ulna

Pronator quadratus: insertion

Distal quarter of anterior surface of radius

Pronator quadratus: innervation

Anterior interosseous nerve

Pronator quadratus: action

Pronation of the forearms

Extensor digitorum: origin

lateral epicondyle of humerus

Extensor digitorum: insertion

Dorsal aspect of medial 4 digits

Extensor digitorum: innervation

posterior interosseous nerve

Extensor digiti minimi: origin

lateral epicondyle of humerus

Extensor digiti minimi: insertion

extensor expansion of the 5th finger

Extensor digiti minimi: innervation

posterior interosseous nerve

Extensor carpi ulnaris: origin

lateral epicondyle of humerus

Extensor carpi ulnaris: insertion

dorsal aspect of the base of the 5th metacarpal

Extensor carpi ulnaris: innervation

posterior interosseous nerve

Extensor Carpi radialis longus: origin

lateral supracondylar ridge of the humerus

Extensor Carpi radialis longus: insertion

dorsal aspect of the base of second metacarpal bone

Extensor Carpi radialis longus: innervation

radial nerve

Extensor carpi radialis brevis: origin

lateral epicondyle of humerus

Extensor carpi radialis brevis: insertion

Dorsal aspect base of the third metacarpal bone