lab 6-7 (muscles)

Sternocleidomastoid

Origin: Manubrium of sternum & medial clavicle Insertion: Mastoid process of temporal bone Action: Flexes head and neck; rotates head

Pectoralis Major

Origin: Clavicle

Trapezius

Origin: Occipital bone and spinous processes C7–T12 Insertion: Clavicle

Latissimus Dorsi

Origin: Spinous processes T7–T12

Rectus Abdominis

Origin: Pubic crest and pubic symphysis Insertion: Xiphoid process and costal cartilages of ribs 5–7 Action: Flexes vertebral column

Triceps Brachii

Origin: Infraglenoid tubercle of scapula; medial and lateral humerus Insertion: Olecranon process of ulna Action: Extends elbow

Biceps Brachii

Origin: Supraglenoid tubercle and coracoid process of scapula Insertion: Radial tuberosity Action: Flexes elbow and supinates forearm

Brachialis

Origin: Distal anterior shaft of humerus Insertion: Coronoid process of ulna Action: Flexes elbow

Rectus Femoris

Origin: Anterior inferior iliac spine (AIIS) Insertion: Tibial tuberosity via patellar tendon and patellar ligament Action: Flexes thigh at hip and extends leg at knee

Vastus Lateralis

Origin: Greater trochanter and linea aspera of femur Insertion: Tibial tuberosity via patellar tendon and patellar ligament Action: Extends leg at knee

Vastus Medialis

Origin: Linea aspera of femur Insertion: Tibial tuberosity via patellar tendon and patellar ligament Action: Extends leg at knee

Biceps Femoris

Origin: Ischial tuberosity and linea aspera of femur Insertion: Head of fibula and lateral condyle of tibia Action: Flexes leg at knee

Semitendinosus

Origin: Ischial tuberosity Insertion: Proximal medial surface of tibia Action: Flexes leg at knee

Semimembranosus

Origin: Ischial tuberosity Insertion: Posterior medial condyle of tibia Action: Flexes leg at knee

Gastrocnemius

Origin: Medial and lateral condyles of femur Insertion: Calcaneus via calcaneal (Achilles) tendon Action: Plantar flexes foot and flexes knee