APPENDICULAR MUSCLES: These muscles control the movement of the upper and lower limbs, pelvic and pectoral girdles.

ACTIVITIES 5 & 6: APPENDICULAR AND AXIAL MUSCLES Laboratory Objectives: 1. Histology: review histology of skeletal muscle tissue. 2. Identify muscles listed on models and/or cadavers. 3. When indicated, identify the action and attachments for each muscle. Skeletal muscle identification: You will be required to identify each of the following muscles or associated structures on the cadavers and/or models in lab. If the table is shaded in a particular box, it means you are not responsible for that information. Muscle actions are required for each muscle. Remember: Spelling is important! Practice writing and rewriting the names of each muscle and associated structure. You are NOT responsible for the innervating each muscle until you do the nervous system activities in laboratory. Note: CN = cranial APPENDICULAR MUSCLES: These muscles control the movement of the upper and lower limbs, pelvic and pectoral girdles. TABLE 1. MUSCLES THAT MOVE THE PECTORAL GIRDLE (FROM BRACHIAL PLEXUS, EXCEPT TRAPEZIUS) Muscles that are attached only to the axial skeleton and thus move the pectoral girdle 1. trapezius -superior fibers: elevate, elevate clavicle -inferior fibers: depress accessory (CN XI) 2. levator e elevates 3. serratus anterior protracts and stabilizes long thoracic 4. pectoralis minor protracts and depresses medial pectoral 5. rhomboid major -elevates and retracts -rotates inferiorly 6. rhomboid minor -elevates and retracts -rotates inferiorly 1

TABLE 2. MUSCLES THAT ATTACH TO THE AXIAL SKELETON AND TO THE HUMERUS. These muscles move the glenohumeral or shoulder joint. ROTATOR CUFF MUSCLES (4 MUSCLES) (BRACHIAL PLEXUS) 1. supraspinatus supraspinous fossa of greater tubercle of humerus 2. infraspinatus infraspinous fossa of greater tubercle of humerus 3. subris subr fossa of lesser tubercle of humerus 4. teres minor lateral border of greater tubercle of humerus 5. teres major lateral border and angle of lesser tubercle and intertubercular 6. latissimus dorsi -spinous processes of lower thoracic vertebrae -lower ribs -iliac crest 7. deltoid -acromial end of clavicle -acromion and spine of groove of humerus intertubercular groove of humerus deltoid tuberosity of humerus collectively, stabilize and rotate shoulder (glenohumeral) joint extends, adducts, and medially rotates arm at shoulder extends, adducts, and medially rotates arm at shoulder (swimming, climbing rope, hammering) abducts, flexes, extends, and rotates arm at shoulder axillary 8. pectoralis major -clavicle -costal cartilages -body of sternum greater tubercle and intertubercular groove of humerus flexes, adducts, and medially rotates arm at shoulder lateral pectoral and medial pectoral TABLE 3. ANTERIOR COMPARTMENT OF THE ARM 1. biceps brachii (BRACHIAL PLEXUS) long head short head supraglenoid tubercle of coracoid process of radial tuberosity -flexes and supinates forearm at elbow -flexes arm at shoulder (weak) musculocutaneous 2. coracobrachialis coracoid process of 3. brachialis distal, anterior surface of humerus middle medial shaft of humerus coronoid process of ulna 4. brachioradialis lateral distal humerus styloid process of radius adducts and flexes arm at shoulder flexes forearm at elbow flexes forearm at elbow musculocutaneous musculocutaneous 2

TABLE 4. POSTERIOR COMPARTMENT OF THE ARM 1. triceps brachii (long, lateral, and medial heads) (BRACHIAL PLEXUS) long head lateral head medial head infraglenoid tubercle of posterior shaft of humerus posterior shaft of humerus distal to radial groove olecranon process of ulna -extends forearm at elbow -assists in arm adduction at shoulder TABLE 5. ANTERIOR COMPARTMENT OF THE FOREARM (BRACHIAL PLEXUS) 1. pronator teres pronates forearm median 2. flexor carpi radialis -flexes wrist -abducts hand at wrist 3. palmaris longus -flexes wrist (weak) -tenses fascia of palm 4. flexor carpi ulnaris -flexes wrist -adducts hand at wrist 5. flexor digitorum superficialis -flexes wrist -flexes joints of digits 2-5 (MP and PIP joints) 6. flexor digitorum profundus -flexes wrist -flexes joints of digits 2-5 (MP, PIP, DIP joints) flexor retinaculum (associated structure) median median ulnar median MP = metacarpophalangeal; IP= interphalangeal; PIP = proximal interphalangeal; DIP = distal interphalangeal 3

TABLE 6. POSTERIOR COMPARTMENT OF THE FOREARM (BRACHIAL PLEXUS) 1. extensor carpi radialis longus -extends wrist -abducts hand at wrist 2. extensor carpi radialis brevis -extends wrist -abducts hand at wrist 3. extensor carpi ulnaris -extends wrist -adducts hand at wrist 4. extensor digitorum -extends wrist -extends joints of digits 2-5 (MP, PIP, DIP joints) 5. abductor pollicis longus -abducts thumb -extends wrist (weak) 6. extensor pollicis longus -extends thumb joints (MP and IP joints) -extends wrist (weak) 7. extensor pollicis brevis - extends thumb joints (MP and IP joints) - extends wrist (weak) 8. supinator supinates forearm extensor retinaculum (associated structure) TABLE 7. ANTERIOR COMPARTMENT OF THE THIGH 1. sartorius anterior superior iliac spine tibial tuberosity, medial side QUADRICEPS FEMORIS GROUP: FOUR MUSCLES WITH A COMMON INSERTION POINT -flexes and laterally rotates thigh -flexes leg and medially rotates leg at knee (sitting crosslegged on floor) (LUMBAR PLEXUS) femoral 2. rectus femoris anterior inferior iliac spine patella via quadriceps tendon and then tibial tuberosity via patellar ligament -extends leg at knee -flexes thigh femoral 3. vastus lateralis extends leg at knee femoral 4. vastus medialis extends leg at knee femoral 5. vastus intermedius extends leg at knee femoral 4

TABLE 8. ILIOPSOAS GROUP 1. iliacus * iliac fossa lesser trochanter of femur flexes thigh (LUMBAR PLEXUS) femoral 2. psoas major* *These two muscles are collectively known as the iliopsoas T 12-L 5 vertebrae lesser trochanter of femur flexes thigh branches of lumbar plexus TABLE 9. MEDIAL COMPARTMENT OF THE THIGH 1. pectineus -adducts thigh -flexes thigh (weak) 2. adductor longus -adducts thigh -flexes thigh (weak) 3. adductor magnus -adducts thigh -flexes,extends and laterally rotates thigh (LUMBAR PLEXUS) femoral or obturator obturator obturator sciatic 4. adductor brevis adducts thigh obturator 5. gracilis inferior ramus and body of pubis proximal medial surface of tibia -adducts thigh -flexes leg at knee obturator TABLE 10. POSTERIOR COMPARTMENT OF THE THIGH HAMSTRINGS GROUP: (3 MUSCLES) 1. semitendinosus ischial tuberosity proximal medial surface of tibia 2. semimembranosus ischial tuberosity medial condyle of tibia 3. biceps femoris long head short head long head: ischial tuberosity short head: linea aspera of femur head of fibula -extends thigh -flexes leg at knee -medially rotates leg at knee -extends thigh -flexes leg at knee -medially rotates leg at knee -extends thigh -flexes and laterally rotates leg at knee (SACRAL PLEXUS) tibial division of sciatic tibial division of sciatic tibial division of sciatic 5

TABLE 11. GLUTEAL MUSCLES 1. tensor fascia latae -iliac crest -anterior superior iliac spine 2. gluteus maximus -iliac crest -sacrum -coccyx iliotibial band -iliotibial band - gluteal tuberosity/ linea aspera of femur 3. gluteus medius iliac crest greater trochanter of femur 4. gluteus minimus lateral surface of ilium greater trochanter of femur 5. piriformis anterior lateral surface of sacrum 6. iliotibial band/tract (associated structure) greater trochanter of femur -abducts thigh -medially rotates thigh -extends thigh -laterally rotates thigh -abducts thigh -medially rotates thigh -abducts thigh -medially rotates thigh laterally rotates thigh (SACRAL PLEXUS) superior gluteal inferior gluteal superior gluteal superior gluteal TABLE 12. ANTERIOR COMPARTMENT OF THE LEG 1. tibialis anterior lateral condyle and proximal shaft of tibia -metatarsal I -medial cuneiform -dorsiflexes foot at -inverts foot at 2. extensor digitorum longus -extends toes 2-5 -dorsiflexes foot at 3. extensor hallucis longus -extends hallux -dorsiflexes foot at (SACRAL PLEXUS) deep fibular deep fibular deep fibular TABLE 13. LATERAL COMPARTMENT OF THE LEG (SACRAL PLEXUS) 1. fibularis (peroneus) longus -everts foot at -plantar flexion at (weak) 2. fibularis (peroneus) brevis -everts foot at -plantar flexion at (weak) superficial fibular superficial fibular 6

TABLE 14. POSTERIOR COMPARTMENT OF THE LEG 1. gastrocnemius lateral and medial condyles of femur 2. soleus -head and proximal shaft of fibula -medial border of tibia calcaneus via calcaneal tendon calcaneus via calcaneal tendon -plantar flexes foot at -flexes leg at knee plantar flexes foot at 3. tibialis posterior -plantar flexes foot at -inverts foot at 4. flexor digitorum longus -plantar flexes foot at -flexes toes 2-5 5. flexor hallucis longus -plantar flexes foot at -flexes joints of hallux (SACRAL PLEXUS) tibial tibial tibial tibial tibial 7

AXIAL MUSCLES: These muscles have both their origins and insertions on the axial skeleton. TABLE 15. MUSCLES OF FACIAL EXPRESSION 1. frontalis (frontal belly of occipitofrontalis) moves scalp forward, raises eyebrows, wrinkles forehead facial (CNVII) 2. occipitalis (occipital belly of occipitofrontalis) moves scalp backward facial (CNVII) 2. orbicularis oris compresses and purses lips (kiss muscle) facial (CNVII) 3. orbicularis oculi closes eye (blink muscle) facial (CNVII) 4. platysma pulls lower lip inferiorly, tenses skin of neck facial (CNVII) 5. zygomaticus major and zygomaticus minor elevates corners of mouth (smiling muscle) facial (CNVII) 6. buccinator compresses cheeks, as in chewing, whistling, playing a wind instrument, and suckling in infants facial (CNVII) TABLE 16. MUSCLES OF MASTICATION (CHEWING) 1. temporalis parietal and frontal coronoid process of bones mandible 2. masseter zygomatic arch coronoid process and ramus of mandible elevates and retracts mandible elevates and protracts mandible; jaw closure trigeminal (CNV) trigeminal (CNV) 8

TABLE 17. NECK MUSCLES 1. sternocleidomastoid -manubrium of sternum -sternal end of clavicle 2. splenius capitis and splenius cervicis ligamentum nuchae (the connective tissue covering the spinal processes of the cervical vertebrae) mastoid process of temporal bone -occipital bone -mastoid process of temporal bone -one side: lateral flexion with rotation of head to opposite side -both sides: flexes head & neck -one side: turns head to same side -both sides: extends head & neck accessory (CNXI) cervical spinal s TABLE 18. MUSCLES OF VERTEBRAL COLUMN Erector spinae groups (3): 1. iliocostalis group (lateral) -one side: laterally bends the vertebral column cervical, thoracic, and lumbar spinal s 2. longissimus group (intermediate) -both sides: extends neck and vertebral column; maintains posture cervical and thoracic spinal s 3. spinalis group (medial) cervical and thoracic spinal s 4. quadratus lumborum (not part of erector spinae groups) -one side: laterally bends the vertebral column -both sides: extends vertebral column thoracic and lumbar spinal s TABLE 19. MUSCLES OF RESPIRATION 1. external intercostals elevates ribs during normal inspiration intercostal s (from thoracic spinal s) 2. internal intercostals depresses ribs during forced exhalation intercostal s (from thoracic spinal s) 3. diaphragm contraction depresses (flattens) diaphragm and expands the thoracic cavity during normal inspiration phrenic s (from cervical plexus) 9

TABLE 20. MUSCLES OF THE ABDOMINAL WALL 1. external oblique -both sides: flexes vertebral column & compresses thoracic spinal s abdominal wall -one side: lateral flexion of vertebral column 2. internal obliques -both sides: flexes vertebral column & compresses thoracic spinal s abdominal wall -one side: lateral flexion of vertebral column 3. rectus abdominis flexes vertebral column & compresses abdominal wall thoracic spinal s 4. transversus abdominis -both sides: flexes vertebral column & compresses abdominal wall -one side: lateral flexion of vertebral column 5. inguinal ligament (associated structure) thoracic spinal s 10