סקירה של שרירי שלד עיקריים

Frontalis O: galea aponeurotica I: eyebrows F: raise eyebrows, pull scalp anteriorly

Occipitalis O: occipital & temporal bones I: galea aponeurotica F: pull scalp posteriorly

Orbicularis oculi O: frontal, maxillary bones I: eyelids F: close eyes

Orbicularis oris O: muscles around mouth I: lips F: close, purse lips

Buccinator O: maxilla & mandible I: orbicularis oris F: compress cheek

Temporalis O: squamous portion of temporal bone I: mandible F: elevate mandible

Muscles of mastication Temporalis O: temporal fossa I: coronoid process of mandible Action: elevate and retract mandible (11.7a)

Masseter O: zygomatic arch I: angle of mandible F: elevate mandible

Muscles of mastication Masseter O: zygomatic arch I: angle & ramus of mandible Action: elevate mandible (11.7a)

Zygomaticus O: zygomatic I: corner of mouth F: smile

Sternocleidomastoid O: sternum & clavicle I: mastoid of temporal bone F: flex and rotate head

Muscles of neck & throat Sternocleidomastoid O: manubrium & medial clavicle I: mastoid process of temporal bone Action: head & neck flexion, rotate head contralaterally (11.8a)

Muscles of neck & throat Sternocleidomastoid

Platysma O: fascia over Pec. major, Deltoid I: mandible & skin F: depress lip & mandible

Shoulder muscles Pectoralis major O: medial clavicle, sternum, cartilage of ribs 1-6, aponeurosis of external oblique I: greater tubercle of humerus Action: arm-flexion, medial rotation, adduction, elevation of rib cage (11.13a)

Superficial thorax muscles Pectoralis minor O:anterior surface of ribs 3-5 I: coracoid process of scapula Action: with ribs fixed, pulls scapula anterior & inferior; with scapula fixed, pulls ribs superiorly (11.13a)

Subclavius Small, round muscles O: 1st rib at costal cartilage I: Middle third of clavicle A: Anchors and depresses clavicle Protects subclavian artery if clavicle fractures

Superificial thorax muscles Trapezius O: occipital bone, ligamentum nuchae, C7-T12 spinous processes I: acromion, spine of scapula, lateral third of clavicle Action: stabilize, elevate, adduct, depress scapula, extend head (11.13b)

Latissimus dorsi Origin: ribs, thoracic & lumbar vertebra, iliac crest of coxal bone Insertion: humerus Action: humerus extension, adduction, medial rotation

Levator scapulae O: cervical vertebrae I: scapula F: elevate scapula, rotate neck

Shoulder muscles Deltoid O: lateral clavicle, acromion & spine of scapula (compare to insertion of trapezius) I: deltoid tuberosity of humerus Action: arm-abduction, flexion, extension, medial & lateral rotation (11.13ab)

Abdominal wall muscles Rectus abdominis O: pubic crest & symphysis I: xiphoid process and costal cartilages of ribs 5-7 Action: flex & rotate lumbar vertebrae, fix & depress ribs, stabilize pelvis during walking, increase intraabdominal pressure Note: 3 tendinous insertions, aponeurosis & linea alba (11.11ab)

External oblique Origin: lower ribs Insertion: linea alba; iliac and pubic crests of coxal bone Action: abdomenal compression, vertebral flexion, trunk rotation, lateral vertebral flexion

Muscles of Anterior Abdominal Wall External Obliques O: lower 8 ribs I: aponeurosis to linea alba Function: Flex trunk, compress abd. wall (together) Rotate trunk (separate sides) Internal Obliques O: Lumbar fascia, iliac crest, inguinal ligament I: Linea alba, pubic crest, last 3-4 ribs, costal margin Function: Same as External obliques Transversus Abdominis O:same as Internals, plus last 6 ribs I: Xiphoid process, costal cart. 5-7 Function: Compress abdomen Rectus Abdominis O: Pubic crest, pubic symphysis I: Xiphoid, cost cart 5-7 Function: Flex, rotate trunk, compress abdomen, fix ribs

Hip & knee muscles Gluteus muscles O: ilium, sacrum, coccyx I: shaft & greater trochanter of femur Action: extend thigh (climb stairs, running), lateral & medial rotate thigh, abduct thigh, steadies pelvis (11.20ab)

Gluteus maximus Origin: saccrum, coccyx, and ilium of coxal bone Insertion: femur & iliotibial tract Action: femur extension & lateral rotation

Hip & knee muscles Quadriceps femoris O: anterior inferior iliac spine, superior margin of acetabulum, greater trochanter, shaft of femur I: patella and tibial tuberosity via patellar tendon Action: extend knee, flex thigh 11.19a

Hip & knee muscles Hamstrings O: ischial tuberosity, shaft of femur I: lateral & medial condyles and shaft of tibia, head of fibula, lateral condyle femur Action: extend thigh, flex knee Makes touching toes hard (11.20a)

Extends Thigh & Flexes Lower Leg Biceps Femoris Extends Thigh & Flexes Lower Leg Biceps femoris is one of the hamstring muscles. *The origin is on the ischial tuberosity. *Biceps femoris inserts on the tibia and fibula. This muscle extends the thigh and flexes the lower leg.

Elbow muscles Biceps brachii O: short head-coracoid process, long head-tubercle above glenoid cavity and lip of glenoid cavity (intertubercular groove) I: radial tuberosity Action: flex elbow, supinate forearm, weak arm flexor (11.14c)

O: humerus I: coronoid process of ulna F: flex forearm Brachialis

Elbow muscles Triceps brachii O: long head-infraglenoid tubercle, lat. & med. heads-posterior shaft of humerus I: olecranon process of ulna Action: extend forearm, assist adduction of arm (11.14b)

Leg muscles Tibialis anterior O: lateral condyle and shaft of tibia I: tarsal and first metatarsal bones Action: dorsiflexion (11.21ab)

Anterior Compartment of the Leg Extensor digitorum longus Tibialis anterior Peroneus tertius Extensor hallucis longus Extensor digitorum longus = extension of toes & ankle Extensor hallucis longus = extension of big toe & ankle Fibularis tertius = dorsiflexes and everts foot Tibialis anterior = dorsiflexes and inverts foot

Leg muscles Gastrocnemius O: medial & lateral condyles of femur I: calcaneus via Achilles tendon Action: plantar flexion, flex knee (11.23a)

Posterior Compartment of the Leg Deep Group of Plantar Flexors Tibialis posterior, Flexor digitorum longus, and Flexor hallucis longus and are plantar flexors.

Forearm muscles Flexor carpi (radialis & ulnaris) O: medial epicondyle of humerus, ulna I: metacarpals and carpals Action: wrist flexion, abduct & adduct hand Carpal tunnel syndrome p. 184 (11.15a) Anterior view

Forearm muscles Extensor carpi O: lateral epicondyle of humerus I: base of metacarpals Action: extend, abduct, and adducts wrist Palpate forearm muscles 11.16a Posterior View