Muscle Anatomy and Actions

Flashcards covering key muscle names, their primary actions, and origins.

Levator scapulae

Elevates scapula, abducts and rotates neck.

Sternocleidomastoideus (SCM)

Rotates and flexes head at cervical spine.

Pectoralis major

Flexes, adducts, and medially rotates humerus.

Pectoralis minor

Depresses shoulder.

Diaphragm

Increases volume in thorax during inhalation.

Trapezius

Extends and abducts head; rotates and adducts scapula; fixator of scapula.

Latissimus dorsi

Extends, adducts, and medially rotates humerus; depresses shoulder.

Vertebrae C1-4

Origin of Levator scapulae.

Manubrium of sternum and medial clavicle

Origin of Sternocleidomastoideus.

Clavicle, sternum, cartilages of ribs 1-7

Origin of Pectoralis major.

Ribs 3-5

Origin of Pectoralis minor.

Xiphoid process of sternum and ribs 7-12

Origin of Diaphragm.

Posterior occipital bone and nuchal ligament

Origin of Trapezius.

T7-12, L1-5, ribs 9-12, iliac crest

Origin of Latissimus dorsi.

Medial border of scapula

Origin of Pectoralis minor.

Mastoid process of temporal bone

Origin of Sternocleidomastoideus.

Crest of greater tubercle of humerus

Insertion of Pectoralis major.

Coracoid process of scapula

Insertion of Pectoralis minor.

Central tendon of diaphragm

Insertion of Diaphragm.

Clavicle, acromion, scapular spine

Insertion of Trapezius.

Intertubercular sulcus of humerus

Insertion of Latissimus dorsi.