Lesson 3 Chapter 11 – Appendicular Musculature

Lesson 3 Chapter 11 – Appendicular Musculature Unit 4 Study Guide Excluded from study: Intrinsic muscle of hand (306-207) & Intrinsic muscle of foot and toe (322-323) Appendicular Skeleton (Upper Limb) Consists of muscles of the pectoral girdle (shoulder), muscles that move the arm, and muscles that move the forearm, and muscles that move the hand. Muscles That Position the Pectoral Girdle Extrinsic Suspend scapula from the trunk. Stabilize and/or actively moves scapula - Trapezius covers the back and portions of the neck. They are innervated by more than one nerve, thus its actions are quite varied. Above the rhomboid. Levator scapulae attach to the dorsal surfaces of the clavicle and thoracic vertebrae. It elevates the scapula. Rhomboids is a deep muscle, covered by the trapezius. It retracts the scapula. Serratus Anterior originates along the ribs. It protracts the scapula & swings shoulder anteriorly. Pectoralis minor attaches to the coracoid process of the scapula. It depresses and protracts shoulder. 1 Lesson 3 Chapter 11 – Appendicular Musculature 2 Muscles That Move the Arm Instrinsic Attach scapula to humerus. 9 muscles cross the shoulder joint and insert on the humerus 2 Prime movers: - Pectoralis major extends between anterior portion of chest and the crest of the greater - tubercle of the humerus. Flexes the joint. Latissimus dorsi extends between thoracic vertebrae and the floor of the intertubercular sulcus of the humerus. Extends the joint. 7 originate in the scapula: - Deltoid Teres Major Coracobrachialis Supraspinatus Infraspinatus Rotator cuff (4 scapular muscles) Subscapularis SITS muscles Teres Minor These four scapulohumeral muscles (SITS) reinforce the glenohumeral joint (shoulder joint). Their tendons form the Lesson 3 Chapter 11 – Appendicular Musculature 3 rotator cuff that reinforces the joint capsule. Contraction of these muscles helps to hold the head of the humerus in the shallow glenoid cavity. The glenohumeral (shoulder joint) is highly mobile but is relatively weak due to the large head of the humerus and the glenoid cavity is shallow. Muscles That Flex the Forearm and Hand Anterior (flexors) in the forearm - Brachioradialis flexion at elbow Branchialis flexion at elbow Biceps brachii flexion at elbow and shoulder; supination - Pronator Teres supinates the forearm, pronates forearm and hand by medial rotation of radius Supinator supinates forearm and hand by lateral rotation of radius - Palmaris longus flexes the wrist Flexor carpi ulnaris flexes the wrist and adducts the hand Flexor carpi radialis flexes the wrist and adducts the hand Flexor digitorum (superficialis and profundus) as above Flexors of elbow Pronator/Supinator Flexors of wrist Posterior (extensors) in the forearm - Anconeus Extension of elbow Triceps brachii lateral head extension of elbow long head as above plus extension and adduction at shoulder medial head extension of elbow - Extensor carpi radialis longus extension and abduction at wrist Extensor carpi radialis brevis extension and abduction at wrist Extensor capri ulnaris extension and adduction at wrist Extensors of elbow Extensors of wrist Lesson 3 Chapter 11 – Appendicular Musculature 4 Lesson 3 Chapter 11 – Appendicular Musculature Appendicular Skeleton (Lower Limb) Muscles That Move the Thigh Gluteal group - Gluteus maximus extension and lateral rotation of hips Gluteus medius abduction and medial rotation of hip Gluteus minimus as above 5 Lesson 3 Chapter 11 – Appendicular Musculature - 6 Tensor fasciae latae abduction and medial rotation at hip, laterally supports knee Lateral rotator group - Obturators (externus and internus) lateral rotation and abduction of hip, help maintain stability and integrity Piriformis as above Gemelli (superior and inferior) as above Quadratus femoris lateral rotation of hip Adductor group - Adductor longus adduction, flexion, and medial rotation at hip Adductor brevis adduction and flexion at hip Adductor magnus whole muscle produces adduction at the hip; anterior part produces flexion - and medial rotation; posterior part produces extension Pectineus flexion and adduction at hip Gracilis Flexion and medial rotation at knee; adduction and medial rotation at hip Illiopsoas group - Illiacus flexion at hip and/or lumbar intervertebral joints Psoas major as above Lesson 3 Chapter 11 – Appendicular Musculature Muscles That Move the Leg Flexors of the Knee 7 Lesson 3 Chapter 11 – Appendicular Musculature - Biceps femoris Flexion at knee; extension and lateral rotation of hip Semimembranosus Flexion at knee; extension and medial rotation of hip Semitendinosus As above Sartorius Flexion at knee; abduction, flexion, and lateral rotation of hip Popliteus Medial rotation of tibia (or lateral rotation of femur) at knee; flexion at knee Extensors of the Knee - Rectus femoris Extension at knee; flexion at hip Vastus intermedius Extension at knee Vastus lateralis As above Vastus medialis As above Muscles That Move the Foot and Toes Superficial group (Posterior compartment) - Gastrocnemius Plantar flexion at ankle; flexion at knee Soleus Plantar flexion at ankle; postural muscle when standing Plantaris Plantar flexion at ankle; flexion at knee Deep Group (Posterior compartment) - Tibialis posterior Inversion of foot; plantar flexion at ankle Flexor digitorum longus Flexion at joints of toes 2-5; plantar flexes ankle 8 Lesson 3 Chapter 11 – Appendicular Musculature - Flexor halluces longus Flexion at joints of great toe; plantar flexes ankle Anterior compartment - Tibialis anterior Inversion of foot; plantar flexion at ankle Extensor digitorum longus Extension of toes 2-5; dorsiflexes ankle Extensor halluces longus Extension at joints of great toe; dorsiflexes ankle Fibularis brevis Eversion of foot and plantar flexion at ankle Fibularis longus Eversion of foot and plantar flexion at ankle; supports ankle; supports longitudinal and transverse arches 9 Lesson 3 Chapter 11 – Appendicular Musculature 10