Chapter 11 Muscles

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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

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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

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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)
4
Muscles of facial expression

• Zygomaticus
• O zygomatic bone
• I corners of mouth
• Action smiling
• Nerve facial / CN VII

Major and Minor
(11.6)
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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)
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Muscles of mastication

• Temporalis
• O temporal fossa
• I coronoid process of mandible
• Action elevate and retract mandible
• Nerve trigeminal n. / CN V

(11.7a)
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Extrinsic tongue muscles

• Styloglossus
• O styloid process of temporal bone
• I tongue
• Action retract elevate tongue
• Nerve hypoglossal n. / CN XII

Styloglossus
(11.7c)
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Extrinsic tongue muscles

• Hyoglossus
• O hyoid bone
• I tongue
• Action depresses tongue
• Nerve hypoglossal n. / CN XII

Hyoid bone
(11.7c)
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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)
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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)
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Muscles of neck throat

• Sternohyoid
• O manubrium medial end of clavicle
• I hyoid bone
• Action depress hyoid

Sternohyoid
(11.8a)
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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)
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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)
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Muscles of neck throat

• Sternocleidomastoid

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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)
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(No Transcript)
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Deep thorax muscles

• External internal intercostals
• OI inferior superior border of ribs
• Action inspiration and expiration

Internal
(11.10a)
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Deep thorax muscles
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)
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(No Transcript)
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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)
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(No Transcript)
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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)
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Superficial thorax muscles
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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)
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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)
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(No Transcript)
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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)

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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
• Nerve Axillary nerve(C5-C-6)

(11.13ab)
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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)
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Shoulder muscles

• Infraspinatus
• O infraspinous fossa
• I greater tubercle of humerus
• Action lateral rotate humerus, stabilized
  shoulder joint
• Nerve Suprascapular nerve

(11.14b)
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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)

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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)
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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
• Nerve Musculocutaneous nerve (C5 C6)

(11.14c)
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(No Transcript)
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Forearm muscles

• Flexor carpi (radialis ulnaris)
• 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
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(No Transcript)
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Forearm muscles

• Extensor carpi
• O lateral epicondyle of humerus
• I base of metacarpals
• Action extend, abduct, and adducts wrist
• Palpate forearm muscles

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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

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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

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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

42
Leg muscles

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

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Leg muscles

• Gastrocnemius
• O medial lateral condyles of femur
• I calcaneus via Achilles tendon
• Action plantar flexion, flex knee