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