Chapter 11 Muscles Muscles of facial expression Muscles of mastication Extrinsic tongue muscles Muscles of the neck and throat Back muscles Deep thorax muscles Abdominal wall muscles Superficial thorax muscles Shoulder muscles Elbow muscles Forearm muscles Hip & knee muscles Leg muscles

Chapter 11 Muscles You are responsible for muscles described in class Origin Insertion Action Nerve - innervation (if given) Be able to recognize muscles in all diagrams of text

Muscles of facial expression Orbicularis oculi Sphincter muscle of eyelid O: frontal & maxillary bones I: tissue of eyelid Action: closes eye Nerve: facial / CN VII (11.6)

Muscles of facial expression Zygomaticus O: zygomatic bone I: corners of mouth Action: smiling Nerve: facial / CN VII Major and Minor (11.6)

Muscles of mastication Masseter O: zygomatic arch I: angle & ramus of mandible Action: elevate mandible Nerve: trigeminal nerve / CN V (foramen ovale) Masseter (11.7a)

Muscles of mastication Temporalis O: temporal fossa I: coronoid process of mandible Action: elevate and retract mandible Nerve: trigeminal n. / CN V (11.7a)

Extrinsic tongue muscles Styloglossus O: styloid process of temporal bone I: tongue Action: retract & elevate tongue Nerve: hypoglossal n. / CN XII Styloglossus (11.7c)

Extrinsic tongue muscles Hyoglossus O: hyoid bone I: tongue Action: depresses tongue Nerve: hypoglossal n. / CN XII Hyoid bone (11.7c)

Muscles of neck & throat Digastric two muscle bellies with an intermediate tendon attached to the hyoid bone O: inferior margin of mandible (anterior belly); mastoid process of temporal bone (posterior belly) I: hyoid bone Action: elevate hyoid, stabilize hyoid, depress mandible Nerve: trigeminal n. / CN V (anterior belly), facial n. / CN VII (posterior belly) Posterior belly Anterior belly (11.8a)

Muscles of neck & throat Stylohyoid O: styloid process of temporal bone I: hyoid bone Action: elevate & retract hyoid, swallow Nerve: facial n. / CN VII Stylohyoid (11.7c)

Muscles of neck & throat Sternohyoid O: manubrium & medial end of clavicle I: hyoid bone Action: depress hyoid Sternohyoid (11.8a)

Muscles of neck & throat Pharyngeal constrictors O: mandible, pterygoid process, hyoid, laryngeal cartilages I: posterior medial raphe of pharynx Action: peristaltic contraction / swallow Superior Middle Inferior (11.8b)

Muscles of neck & throat Sternocleidomastoid O: manubrium & medial clavicle I: mastoid process of temporal bone Action: head & neck flexion, rotate head contralaterally Nerve: accessory n. / CN XI (11.8a)

Muscles of neck & throat Sternocleidomastoid

Back muscles Spinalis O: spines of upper lumbar and lower thoracic vertebrae I: spines of upper thoracic and cervical vertebrae Action: extends vertebral column (11.9d)

Deep thorax muscles External & internal intercostals O&I: inferior & superior border of ribs Action: inspiration and expiration Internal (11.10a)

Deep thorax muscles Diaphragm Xiphoid process Diaphragm O: inferior internal surface of rib cage & sternum, inferior costal cartilages, lumbar vertebrae I: central tendon Action: flattens on contraction (inspiration) Nerve: phrenic nerves (11.10b)

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)

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 Nerve: Medial and lateral pectoral nerves (C6-C8) (11.13a)

Superficial thorax muscles

Superificial thorax muscles Serratus anterior O: ribs 1-8 I: vertebral border of scapula Action: hold scapula against chest wall, moves inferior angle of scapula lateral & superior (abduction, pushing, punching) Nerve: long thoracic nerve (11.13a,8.1a reversed)

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 Nerve: Accessory (CNXI), C3 and C4 (11.13b)

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) Nerve: Medial and lateral pectoral nerves (C6-C8)

Shoulder muscles Deltoid (11.13ab) 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 Nerve: Axillary nerve(C5-C-6) (11.13ab)

Shoulder muscles Subscapularis O: subscapular fossa I: lesser tubercle of humerus Action: medial rotate arm, stabilize shoulder joint Nerve: Subscapular nerves (C5-C7) (11.14d)

Shoulder muscles Infraspinatus O: infraspinous fossa I: greater tubercle of humerus Action: lateral rotate humerus, stabilized shoulder joint Nerve: Suprascapular nerve (11.14b)

Rotator cuff muscles Act to stabilize head of humerus in glenoid cavity and prevent dislocation Supraspinatous (Suprascapular nerve) Infraspinatus (Suprascapular nerve) Subscapularis (Subscapular nerve) Teres minor (Axillary nerve)

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 Nerve: Radial nerve (11.14b)

Elbow muscles Biceps brachii (11.14c) 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 Nerve: Musculocutaneous nerve (C5 & C6) (11.14c)

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

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

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

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

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

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