MUSCLES OF THE BODY You need to be able to know the location and action of these muscles!!! Occipitalis Wrinkle forehead, elevate eyebrow Frontalis Wrinkle forehead, elevate eyebrow Orbicularis Oculi Blinks eye Orbicularis Oris Closes Lips Buccinator Compresses cheek Zygomaticus Helps to smile (lift corners of lips) Platysma Helps to frown (lower corners of lips) Temporalis Close jaw Masseter Close jaw Sternocleidomastoid Flex neck and rotate head Trapezius Extends head, rotates and adducts scapula Latissimus Dorsi Extend, adduct & rotate arm medially Deltoid Abducts & flexes arm Pectoralis Major Flexes, adducts & rotates arm medially Rotator Cuff Group of 4 muscles that rotates & stabilizes arm Supraspinatus, Infraspinatus, Subscapularis, Teres Minor Erector Spinae Rotates and extends vertebral column and head External Intercostals Elevate ribs (inspiration) Internal Intercostals Depress ribs (forced expiration) Diaphragm Inspiration Rectus Abdominis Flexes & compresses abdomen External Oblique Compresses abdomen Internal Oblique Compresses abdomen Transversus Abdominis Compresses abdomen Biceps Brachii Flexes elbow joint (forearm) Triceps Brachii Extend elbow joint (forearm) Brachialis Flexes elbow joint (forearm) Brachioradialis Flexes elbow joint (forearm) Forearm Muscles • Flexor carpi ulnaris – flexes wrist • Flexor carpi radialis – flexes wrist Forearm Muscles • Extensor carpi radialis extends wrist Forearm Muscles • Extensor carpi ulnaris extends wrist Forearm Muscles • Flexor digitorum flexes fingers Forearm Muscles • Extensor digitorum extends fingers Right Arm, Anterior Side (Palm side up) Right Arm, Posterior Side (Palm side down) Gluteus Maximus Extends & rotates thigh laterally Gluteus Medius Abducts & rotates thigh Upper Leg Muscles Rectus Femoris Flexes Thigh, Extends Lower Leg (part of quadriceps) Vastus Lateralis Extends Lower Leg (part of quadriceps) Vastus Medialis Extends Lower Leg (part of quadriceps) The 4th muscle of the “quad” group is the Vastus Intermedius, which is hidden below the other three! 1. vastus medialis 2. vastus lateralis 3. vastus intermedius 4. rectus femoris Sartorius Flexes & laterally rotates thigh (longest muscle of the body!) Adductor Muscles Adducts thigh Gracilis, Adductor Magnus, Adductor Longus, Adductor Brevis Biceps Femoris Flex knee and extend hip (part of hamstring group) Semimembranosus Flex knee and extend hip (part of hamstring group) Semitendinosus Flex knee and extend hip (part of hamstring group) Tibialis Anterior Dorsiflexes and inverts foot Gastrocnemius Plantar flexes foot & flex lower leg (calf muscle) Soleus Plantar flexes foot Fibularis Longus Plantar flexes & everts foot Extensor Digitorum Longus Extends toes