Pectoral and Anterior Shoulder/Arm Flashcards
Platysma Origin
fascia of the upper thorax and lower neck
Platysma Insertion
mandible (along chin), skin of the face over the mandible (along chin), muscles of the lower lip and angle of mouth
Platysma Action
Pulls on skin of neck (elevates) to give expression of “horror” or “fright”. Depression of lower lip and angle of mouth
Platysma Innervation
facial nerve (Cranial Nerve VII)
Platysma Blood supply
facial artery
Sternocleidomastoid Origin
manubrium of sternum; medial 1/3 of clavicle
Sternocleidomastoid Insertion
mastoid process of temporal bone
Sternocleidomastoid Actions
rotates head and neck while elevating chin (one side working) flexes head and neck (both sides working)
Sternocleidomastoid Innervation
accessory nerve (Cranial Nerve XI)
Sternocleidomastoid Blood supply
occipital artery
Pectoralis Major Origin
medial 2/3 of clavicle (clavicular portion), entire length of sternum (sternocostal portion), upper 6 costal cartilages
(sternocostal portion)
Pectoralis Major Insertion
crest of greater tubercle of humerus
Pectoralis Major Actions
flexion of humerus (clavicular portion only), extension of humerus (sternocostal portion only), adduction of humerus, medial
rotation of humerus
Pectoralis Major Innervation
lateral pectoral nerve (clavicular portion), medial pectoral nerve (sternocostal portion)
Pectoralis Major Blood supply
thoracoacromial artery
Pectoralis Minor Origin
ribs 3, 4 and 5
Pectoralis Minor Insertion
coracoid process of scapula
Pectoralis Minor Actions
protraction of scapula, depression of scapula, downward rotation of scapula
Pectoralis Minor Innervation
medial pectoral nerve
Pectoralis Minor Blood supply
thoracoacromial artery
Serratus Anterior Origin
anterolateral surface of ribs 1-8
Serratus Anterior Insertion
medial border of scapula, inferior angle of scapula
Serratus Anterior Action
protraction of scapula, upward rotation of scapula, depression of scapula
Serratus Anterior Innervation
long thoracic nerve
Serratus Anterior Blood supply
lateral thoracic artery
Deltoid Origin
lateral 1/3 of clavicle, acromion process of scapula, spine of scapula
Deltoid Insertion
deltoid tuberosity of humerus
Deltoid Action
anterior fibers: flexion of humerus, medial rotation of humerus
lateral fibers: abduction of humerus after first 5-10°
posterior fibers: extension of humerus, lateral rotation of humerus
Deltoid Innervation
Axillary n.
Deltoid Blood supply
thoracoacromial trunk and anterior and posterior circumflex humeral aa.
Biceps brachii Origin
coracoid process of scapula (short head); supraglenoid tubercle of scapula (long head)
Biceps brachii Insertion
radial tuberosity of radius, bicipital aponeurosis
Biceps brachii Action
forearm supination, forearm, and weak role shoulder flexion
Biceps brachii Blood supply
brachial a.
Coracobrachialis Origin
coracoid process of scapula
Coracobrachialis Insertion
mid-medial surface of humerus
Coracobrachialis Action
flexion of humerus, adduction of humerus
Coracobrachialis Innervation
musculocutaneous n.
Coracobrachialis Blood supply
brachial and anterior circumflex humeral a.
Brachialis Origin
lower anterior surface of humerus
Brachialis Insertion
ulnar tuberosity of ulna
Brachialis Action
flex forearm
Brachialis Innervation
musculocutaneous nerve
Brachialis Blood supply
brachial a.