Origins, Insertions, Actions, and Innervations of the Upper Extremities Flashcards
Origin of the Pectoralis Major
Clavicle, Sternum and Upper Ribs, and the tendon of the external oblique
Insertion of the Pectoralis Major
Greater Tubercle (Intertubecular groove) of the humerus
Action of the Pectoralis Major
Entire muscle: adduction and medial rotation of the humerus, forced inspiration when the humerus is fixed
Clavicular Portion: flexes the humerus at the shoulder joint
Sternocostal portion: extends the humerus at the shoulder joint (when the humerus is flexed)
Nerve supply of the Pectoralis Major
Medial and Lateral pectoral nerves
Origin of the Pectoralis Minor
Upper ribs
Insertion of the Pectoralis Minor
Coracoid process of the scapula
Action of the Pectoralis Minor
Protraction and abduction of the scapula. Also elevates the ribcage (forced inspiration)
Nerve supply of the Pectoralis Minor
Medial pectoral nerve
Origin of the subclavius
First rib
Insertion of the Subclavius
Subclavian groove of the clavicle
Action of the Subclavius
Moves the clavicle medially and acts as a protective cushion between the clavicle and subclavian vessels
Nerve supply of the Subclavius
Nerve to the subclavius
What muscles compose the pectoral region?
Pectoralis Major, pectoralis minor, and the subclavius
Origin of the trapezius
Superior nuchel line of occiput, external occipital protuberance, ligamentum nuchae, and the spines of the thoracic vertebrae
Insertion of the trapezius
The clavicle as well as the acromion process and spine of the scapula
Actions of the trapezius
Stabilizes the scapula,
Upper portion: elevates the scapula
Middle and lower portions: adducts the scapula
Nerve supply of the trapezius
Motor: spinal accessory nerve
Sensory: C4, C5
Origin of the rhomboid major
Spine of the upper thoracics
Insertion of the rhomboid major
Vertebral border of the scapula
Actions of the rhomboid major
Elevates and adducts the scapula. Also helps to stabilize the scapula
Nerve supply of the rhomboid major
Dorsal scapular nerve
Origin of the rhomboid minor
Spine of the lower cervical and T1
Insertion of the rhomboid minor
Vertebral border of the scapula
Action of the rhomboid minor
Elevates and adducts the scapula. Also helps to stabilize the scapula
Nerve supply of the rhomboid minor
Dorsal Scapular nerve
Origin of the levator scapula
Transverse processes of the upper cervical vertebrae
Insertion of the levator scapula
Superior angle of the scapula
Action of the levator scapula
Elevates and adducts the scapula. Also stabilizes the scapula
Nerve supply of the levator scapula
Dorsal scapular nerve
Origin of the Latissimus dorsi
Spines of the lower thoracic and lumbar vertebrae
Thoracodorsal fascia
Crest of the ilium
Insertion of the latissimus dorsi
Intertubecular groove (lesser tubercle) of the humerus
Action of the latissimus dorsi
Extends, adducts, and medially rotates the humerus. Also involved with forced expiration
Nerve supply of the latissimus dorsi
Thoracodorsal nerve
Origin of the serratus anterior
Upper ribs
Insertion of the serratus anterior
Vertebral border of the scapula
Action of the serratus anterior
Abduction and protraction of the scapula, stabilizes the scapula, and is involved with forced inspiration if the humerus is abducted
Nerve supply of the serratus anterior
Long thoracic nerve
What muscles compose the shoulder muscles?
Trapezius, rhomboid major, rhomboid minor, levator scapula, latissimus dorsi, and serratus anterior
Origin of the deltoid
Anterior head: clavicular portion from the clavicle
Middle head: acromial portion from the acromion process of the scapula
Posterior head: spinous portion
Insertion of the deltoid
Deltoid tuberosity of the humerus
Action of the deltoid
Anterior portion: flexes and medially rotates the arm
Middle portion: abducts the arm
Posterior portion: extends and laterally rotates the arm
Nerve supply of the deltoid
Axillary nerve
Origin of the supraspinatus
Supraspinous fossa of the scapula
Insertion of the supraspinatus
Greater tuberosity of the humerus
Action of the supraspinatus
Initiates abduction of the arm, helps to laterally rotate the humerus, and helps stabilize the shoulder joint
Innervation of the supraspinatus
Suprascapular nerve
Origin of the Infraspinatus
Infraspinous fossa of the scapula
Insertion of the infraspinatus
Greater tuberosity of the humerus
Action of the infraspinatus
Laterally rotates the humerus and stabilizes the shoulder joint
Nerve supply of the infraspinatus
Suprascapular nerve
Origin of the subscapularis
Subscapular fossa of the scapula
Insertion of the subscapularis
Lesser tuberosity of the humerus
Action of the subscapularis
Medially rotates the humerus and stabilizes the shoulder joint
Nerve supply of the subscapularis
Upper and lower subscapular nerve
Origin of the teres major
Inferior angle of the scapula
Insertion of the teres major
Intertubecular groove (lesser tuberosity) of the humerus
Action of the teres major
Adducts the humerus, stabilizes the shoulder joint, and medially rotates the humerus
Nerve supply of the teres major
Lower subscapular nerve
Origin of the teres minor
Axillary border of the scapula
Insertion of the teres minor
Greater tuberosity of the humerus
Action of the teres minor
Laterally rotates the humerus and stabilizes the shoulder joint
Nerve supply of the teres minor
Axillary nerve
What muscles compose the scapular muscles
Deltoid, supraspinatus, infraspinatus, supscapularis, teres major, and teres minor
Origin of the short head of the biceps brachii
Coracoid process of the scapula
Origin of the long head of the biceps brachii
Supraglenoid tubercle of the scapula
Insertion of the biceps brachii
Tuberosity of the radius and shaft of the ulna
Action of the biceps brachii
Flexion of the forearm and supinates the radius (prime mover)
Nerve supply of the biceps brachii
Musculocutaneous nerve
Origin of the coracobrachialis
Coracoid process of the scapula
Insertion of the coracobrachialis
Shaft of the humerus
Action of the coracobrachialis
Flexion and weak adduction of the arm at the shoulder joint. Also stabilizes the shoulder joint
Nerve supply of the coracobrachialis
Musculocutaneous nerve
Origin of the brachialis
Shaft of the humerus
Insertion of the brachialis
Coronoid process of the ulna
Action of the brachialis
Flexes the forearm (equal prime mover)
Nerve supply of the brachialis
Musculocutaneous nerve
Origin of the long head of the triceps brachii
Infraglenoid tubercle of the scapula
Origin of the lateral head of the triceps brachii
Shaft of the humerus
Origin of the medial head of the triceps brachii
Shaft of the humerus
Insertion of the triceps brachii
Olecranon process of the ulna
Action of the triceps brachii
Extension of the forearm
Nerve supply of the triceps brachii
Radial nerve
What muscles compose the arm?
Biceps brachii, coracobrachialis, brachialis, and the triceps brachii