Anterior & posterior axio-appendicular/ Scapulohumeral muscles Flashcards
What is the proximal attachment of the trapezius.
Proximal attachment: external occipital protuberance, nuchal line, nuchal ligament, spinous processes of C7- T12 vertebrae.
What is the distal attachment of the trapezius.
Distal attachment: clavicle, acromion, and spine of scapula
What innervates the trapezius muscle.
Innervation: spinal accessory nerve (CN 11) -motor fibers. And C3, C4 spinal nerves -pain and proprioceptive fibers
What is the muscle action of the trapezius muscle?
Descending part elevates; ascending part depresses; and middle part or all parts together retracts scapula; descending and ascending parts act together to rotate glenoid cavity superiorly.
What is the proximal attachment of the supraspinatus?
Proximal attachment: supraspinous fossa of scapula
What is the distal attachment of the supraspinatus?
Distal attachment: superior facet of greater tubercle of humerus
What innervates the supraspinatus muscle?
Innervation: suprascapular nerve (C4, C5,C6)
What is the muscle action of the supraspinatus?
Muscle action: initiates and assists deltoid in abduction of arm and acts with rotator cuff muscles.
What is the proximal attachment of the infraspinatous?
Proximal attachment: infraspinous fossa of the scapula
What is the distal attachment of the infraspinatus?
Distal attachment: middle facet of greater tubercle of humerus
What innervates the infraspinatus muscle?
Innervation: suprascapular nerve (C5, C6)
What is the muscle action of the infraspinatus muscle?
Muscle action: laterally rotates arm; and acts with rotator cuff muscles
What is the proximal attachment of the levator scapulae?
Proximal attachment: transverse processes of C1-C4 vertebrae
What is the distal attachment of the levator scapulae?
Medial border of scapula superior to root of scapular spine
What nerve innervates the levator scapulae?
Innervation: dorsal scapular (C4,C5) and cervical nerves (C3,C4)
What is the muscle action of the levator scapulae?
Muscle action: elevates scapula and rotates it’s glenoid cavity inferiorly by rotating the scapula
What is the proximal attachment of the rhomboid minor?
Proximal attachment: nuchal ligament, spinous process of C7-T1 vertebrae
What is the distal attachment of the rhomboid minor?
Distal attachment: triangular area at medial end of scapular spine
What nerve innervates the rhomboid minor and major?
Innervation: dorsal scapular nerve (C4,C5)
What is the muscle action of the rhomboid minor and major?
Muscle action: retracts scapula and rotates it’s glenoid cavity inferiorly, fixes the scapula to the thoracic wall
What is the proximal attachment of the rhomboid major?
Proximal attachment: spinous processes of T2-T5 vertebrae
What is the distal attachment of the rhomboid major?
Distal attachment: medial border of scapula from spine to inferior angle
What is the proximal attachment of the teres minor?
Proximal attachment: middle part of lateral border of scapula
What is the distal attachment of the teres minor?
Distal attachment: inferior facet of greater tubercle of humerus
What nerve innervates the teres minor?
Innervation: axillary nerve (C5, C6)
What is the muscle action of the teres minor?
Muscle action: laterally rotates arm, and acts with rotator cuff muscles
What is the proximal attachment of the teres major?
Proximal attachment: posterior surface of the inferior angle of the scapula
What is the distal attachment of the teres major?
Distal attachment: medial lip of intertubercular sulcus of the humerus
What nerve innervates the teres major?
Lower subscapular nerve (C5, C6)
What is the muscle action of the teres major?
Muscle action: adducts and medially rotates arm
What is the proximal attachment of the latissimus dorsi?
Proximal attachment: spinous process of T6-T12 vertebrae, thoracolumbar fascia, iliac crest, and inferior 3 or 4 ribs.
What is the distal attachment of the latissimus dorsi?
Distal atachment: floor of intertubercular sulcus of humerus.
What nerve innervates the latissimus dorsi?
Thoracodorsal nerve (C6, C7, C8)
What is the muscle action of the latissimus dorsi?
Extends, adducts, and medially rotates humerus; raises body toward arms during climbing.
What is the proximal attachment of the pectoralis major?
Clavicle, sternum, superior 6 costal cartilages, aponeurosis of external oblique muscles.
What is the distal attachment of the pectoralis major?
Lateral lip of thr intertubercular sulcus of humerus.
What nerve innervates the pectoralis major?
Lateral (C5,C6, C7) and medial (C8,T1) pectoral nerves.
What is the muscle action of the pectoralis major?
Adducts and medially rotates humerus, draw scapula anteriorly and inferiroly.
What is the proximal attachment of the pectoralis minor?
3rd-5th ribs near their costal cartilages.
What is the distal attachment of the pectoralis minor?
Medial border and superior surface of coracoid process of scapula.
What nerve innervates the pectoralis minor?
Medial pectoral nerve (C8,T1)
What is the muscle action of the pectoralis minor?
Stabilizes scapula by drawing it inferiorly and anteriorly against thoracic wall.
What is the proxiaml attachment of the subclavius?
Junction of 1st rib and its costal cartilage
What is the distal attachment of the subclavius?
Clavicle
What nerve innervates the subclavius muscle?
Nerve to subclavius (C5,C6)
What is the muscle action of the subclavius?
Anchors and depresses clavicle
What is the proximal attachment of the serratus anterior?
1st-8th ribs
What is the distal attachment of the serratus anterior?
Anterior surface of medial border of scapula
What nerve innervates the serratus anterior?
Long thoracic nerve (C5,C6,C7)
What is the muscle action of the serratus anterior?
Protracts scapula and holds it against thoracic wall, rotates scapula
What is the proximal attachment of the biceps brachii?
Short head: tip of coracoid process of scapula
Long head: supraglenoid tubercle of scapula
What is the distal attachment of the biceps brachii?
Tuberosity of radius and fasica of forearm via bicipital aponeurosis
What nerve innervates the biceps brachii?
Musculocutaneous nerve (C5,C6,C7)
What is the muscle action of the biceps brachii?
Supinates forearm and flexes forearm, short head resists dislocation of shoulder
What is the proximal attachment of the coracobrachialis?
Tip of coracoid process of scapula
What is the distal attachment of the coracobrachialis?
Middle third of medial surface of humerus
What nerve innervates the coracobrachialis muscle?
Musculocutaneous nerve (C5,C6,C7)
What is the muscle action of the coracobrachialis?
Helps flex and adduct arm, resists dislocation of shoulder
What is the proximal attachment of the brachialis?
Anterior surface of the humerus
What is the distal attachment of the brachialis?
Coronoid process and tuberoisty ulna
What nerve innervates the brachialis?
Musculocutaneous nerve (C5,C6) and radial nerve (C5,C7)
What is the muscle action of the brachialis?
Flexes forearm in all positions
What is the proximal attachment of the triceps brachii?
Long head: infraglenoid tubercle of scapula
Lateral head: posterior surface of humerus superior to radial groove.
Medial head: posterior surface of humerus inferior to radial groove
What is the distal attachment of the triceps brachii?
Proximal end of olrecranon of ulna and fascia of forearm
What nerve innervates the triceps brachii?
Radial nerve (C6,C7.C8)
What is the muscle action of the triceps brachii?
Chief extensor of forearm; long head resists dislocation of humerus; especially important during adduction
What is the proximal attachment of the aconeus?
Lateral epicondyle of humerus
What is the distal attachment of the aconeus?
Lateral surface of olecranon and superior part of posterior surface of ulna
What nerve innervates the aconeus?
Radial nerve (C7,C8,T1)
What is the muscle action of the aconeus?
Assists triceps in extending forearm, stabilizes elbow joint
