Muscular System - Diagrams

Head & Neck Muscles Frontalis: elevate eyebrows  Orbicularis Oculi: close eyelid  Zygomaticus: draw angle of lip upward  Buccinator: draws cheeks against teeth Orbicularis Oris: closes mouth  Platysma: draws lower lip down & back  Cranial Aponeurosis: connects frontalis to occipitalis Temporalis: elevates mandible Occipitalis: draws scalp back Masseter: elevates mandible Sternocleidomastoid: Flexes head Draws head toward shoulder

Head & Neck Muscles

Muscles of Mastication Masseter: elevates mandible Temporalis: elevates mandible acts as synergist to masseter Buccinator – holds food between teeth when chewing

Key Muscles of Facial Expression Smiling Muscles Orbicularis Oculi Zygomaticus Frowning Muscles Frontalis Orbicularis Oris Platysma

Anterior Neck/Shoulder Muscles

Post. Neck/Back Muscles

Muscles of the Axial Skeleton

Muscles of the Axial Skeleton Muscles of Quiet Respiration Diaphragm External Intercostals Internal Intercostals—deep breaths Abdominal Muscles External Obliques Internal Obliques Transverse Abdominus Rectus Abdominus Intrinsic Muscles Erector Spinae: maintain posture of back/extension Spinalis Longissimus Iliocostalis Oblique Muscles: rotation of the vertebrae Semispinalis

Anterior Muscles of Shoulder Deltoid Flexion/Extension Abduction /Adduction Internal/External Rotation Pectoralis Major Adduction Flexion Extension Internal Rotation Biceps Brachii—Flexion

Muscles of Scapular Stabilization Trapezius: Retraction Elevation Depression Upward Rotation Rhomboid—retraction Levator Scapular—Elevation Pectoralis Major—Protraction Serratus Anterior—Protraction

Muscles of the Forearm

Muscles of the Forearm

Post. Shoulder/Back Muscles

Posterior Muscles of Shoulder Teres Major Adduction Extension Internal Rotation Latissimus Dorsi Triceps Brachii

Rotator Cuff Muscles (SITS) Teres Minor External Rotation Subscapularis Internal Rotation Supraspinatus Abduction Infraspinatus External Rotation

Muscles of Hip: Anterior Muscles Medial/Adductor Muscles: (forms the muscle mass at the medial side of each thigh) Adductor Magnus Adductor Longus Adductor Brevis Gracilis Anterior Muscles Iliopsoas—prime mover of hip flexion Pectineus— Flexion Adduction Sartorius— Lateral Rotation

Muscles Of Hip: Anterior Muscles

Muscles of Hip: Gluteal Muscles Gluteus Maximus—Hip extension, esp. when climbing stairs or jumping Gluteus Medius— Hip abduction; steady pelvis. Site for injections Gluteus Minimus—Hip abduction Tensor Fasciae Latae— Flexion Abduction ** Gluteus Minimus is under the Gluteus Medius

Muscles of Anterior Thigh “Quadriceps” As a group act as powerful knee extensors Rectus Femoris— Hip flexion Knee extension Vastus Lateralis—knee extension Vastus Medialis—knee extension Vastus Intermedius—knee extension Sartorius—most superficial Hip & Knee Flexion - weak Lateral Hip Rotation “cross-legged position” **Vastus Intermedius is beneath Rectus Femoris

Muscles of Posterior Thigh “Hamstrings” Butchers use their tendons to hang “hams” for smoking Responsible for Knee Flexion & Hip Extension Semimembranosus Semitendinosus Biceps Femoris Gastrocnemius Prime mover for plantar flexion of the foot

Muscles of the Lower Leg Anterior Compartment Tibialis Anterior—Dorsiflexion & inversion Extensor Digitorum Longus Fibularis Tertius—dorsiflexion & eversion Posterior Compartment Gastrocnemius—plantar flexion, knee flexion Soleus—plantar flexion Lateral Compartment Fibularis Longus—plantar flexion & eversion Fibularis Brevis—plantar flexion & eversion

Muscles of the Leg

Muscles of the Leg

ANTERIOR MUSCLES OF THE BODY

POSTERIOR MUSCLES OF THE BODY