Gross Anat I Wet Lab 3 Muscles

Biceps brachii - Long head

Origin: 

• Long head: Supraglenoid tubercle

• Short head: Coracoid process

Insertion: Radial tuberosity

Action: Forearm flexion, supination; accessory arm flexor (long head only)

Innervation: Musculocutaneous nerve

Biceps brachii - Short head

Origin: 

• Long head: Supraglenoid tubercle

• Short head: Coracoid process

Insertion: Radial tuberosity

Action: Forearm flexion, supination; accessory arm flexor (long head only)

Innervation: Musculocutaneous nerve

Coracobrachialis

Origin: Coracoid process

Insertion: Medial humeral shaft

Action: Arm flexion, adduction

Innervation: Musculocutaneous nerve

Brachialis

Origin: Anterior humeral shaft

Insertion: Ulnar tuberosity

Action: Forearm flexion

Innervation: Musculocutaneous nerve

Pectoralis major

Origin: Anterior clavicle and sternum; first 7 costal cartilages; aponeurosis of external oblique abdominis

Insertion: Intertubercular sulcus

Action: Flexion, adduction and medial rotation; flexion of extended arm; extension of flexed arm

Innervation: Medial & lateral pectoral nerves

Pectoralis minor

Origin: Ribs 3-5

Insertion: Coracoid process

Action: Scapular protraction

Innervation: Medial pectoral nerve

Subclavius

Origin: First rib

Insertion: Groove for the subclavius (on clavicle)

Action: Pulls clavicle medially to stabilize SC joint

Innervation: Nerve to the subclavius

Serratus anterior

“Buddy muscle”

Origin: Upper 8-9 ribs

Insertion: Medial border of scapula

Action: Protraction, assists abduction; keeps med. border/inf. angle opposed to thoracic wall

Innervation: Long thoracic nerve