Epicranius (occipitofrontalis)
origin
frontal belly: epicranial \n aponeurosis; occipital belly: \n occipital and temporal bones
insertion
frontal belly: skin of eyebrows \n and bridge of nose; \n occipital belly: epicranial \n aponeurosis
action
frontal belly: raises eyebrows \n and wrinkles forehead; \n occipital belly: tenses and \n retracts scalp
Nasalis
origin
maxillary bone; alar cartilage of \n nose
insertion
bridge of nose
Action
compresses and dilates nostrils
Orbicularis oculi
origin
medial aspect of bony orbit \n
insertion
skin around eyelids \n
action
closes eyes
orbicularis oris
origin \n maxillary bone; mandible
insertion
lips
action
closes mouth; protrudes lips
Levator labii superioris
origin
inferior aspect of bony orbit \n
insertion
skin and muscle of upper lip \n
action \n elevates upper lip
zygomaticus minor
origin
zygomatic bone
insertion
upper lip
action
elevates upper lip
zygomatic major
origin
zygomatic bone
insertion
angle of mouth
action
elevates lateral corners of mouth \n for smiling
buccinator
origin
maxillary bone; mandible \n
insertion
blends with fibers of orbicularis oris \n
action \n compresses cheek
depressor angle oris
origin
anterolateral surface of mandible \n
insertion
skin at angle of mouth
action
depresses angle of mouth
depressor labii inferoris
origin
anterolateral surface of mandible
insertion
skin of lower lip \n
action \n depresses lower lip
mentalis
origin
anterior surface of mandible
insertion
skin of chin
action
protrudes lower lip; wrinkles \n skin on chin
masseter
origin
zygomatic arch
insertion
lateral surface of mandibular \n ramus
action
elevates mandible to close jaw; \n protrudes mandible
temporalis
origin
temporal bone
insertion
coronoid process of mandible \n
action
elevates mandible to close jaw; \n retrudes mandible
lateral pterygoid
origin \n lateral pterygoid plate
insertion
neck of mandible
action
depresses mandible to open jaw; \n protrudes mandible; lateral \n excursion
Sternocleidomastoid
origin
manubrium; medial one-third of \n clavicle
insertion
mastoid process; occipital bone \n near mastoid process
action
flexion and lateral flexion of \n neck; rotates head so that face is \n turned superiorly and to the \n opposite side
scalenes (anterior, middle, posterior)
origin
transverse processes of cervical \n vertebrae
insertion
first two ribs
action
flexion, lateral flexion, and \n slight rotation of neck; elevation \n of first and second ribs
levator scapulae
origin \n transverse processes of superior four \n cervical vertebrae
insertion
medial border of scapula near \n superior angle
action
elevates scapula; inferior \n rotation of scapula
splenius
origin
spinous processes of inferior \n cervical and superior thoracic \n vertebrae
insertion
mastoid process, occipital bone \n and transverse processes of \n superior cervical vertebrae
action
laterally flexes, rotates, and \n extends head and neck
digastric
origin
anterior belly: inferior margin of \n mandible \n posterior belly: mastoid process
insertion
hyoid bone
action
anterior belly: inferior margin of \n mandible \n posterior belly: mastoid process
stylohyoid
origin \n styloid process of temporal bone \n
insertion
hyoid bone \n
action
elevates and retracts hyoid bone
mylohyoid
origin
mylohyoid line of mandible
insertion
hyoid bone \n
action \n elevates hyoid bone, tongue, \n and floor of mouth
Geniohyoid
origin \n inferior mental spine on posterior \n surface of mandible
insertion
hyoid bone
action
elevates and protracts hyoid \n bone; depresses mandible
hypoglossus
origin
hyoid bone
insertion
tongue
action \n depresses and retracts tongue
Sternohyoid
origin
manubrium and clavicle
insertion
hyoid bone
action
depresses larynx and hyoid bone
Sternothyroid
origin
posterior surface of manubrium \n
insertion
thyroid cartilage \n
action
depresses larynx and hyoid bone
Thyrohyoid
origin
thyroid cartilage of larynx \n
insertion
hyoid bone
action \n depresses hyoid bone; elevates \n larynx
Omohyoid
origin
superior border of scapula \n
insertion
hyoid bone \n
action
depresses and retracts hyoid \n bone
Pectoralis major
origin \n medial half of clavicle; sternum; \n costal cartilages of ribs 1-6 \n
insertion
lateral lip of intertubercular \n groove on humerus \n
action
flexion, medial rotation, and \n adduction of the arm
Pectoralis minor
origin
external surfaces of ribs 3-5 \n
insertion
coracoid process of scapula \n
action
depression and inferior rotation \n of scapula
Serratus anterior
action
external surfaces of ribs 1-8 \n
insertion
medial border of scapula
action
protraction and superior rotation \n of scapula; holds scapula against \n thoracic wall
Trapezius
origin
posterior surface of occipital bone; \n ligamentum nuchae; spinous \n processes of thoracic vertebrae
insertion
lateral third of clavicle; \n acromion process; spine of \n scapula \n
action
descending part: elevates scapula \n transverse part: retracts scapula \n ascending part: depresses \n scapula
Latissimus dorsi
origin
spinous processes of vertebrae T6- \n T12; thoracolumbar fascia; iliac \n crest; inferior three ribs
insertion
intertubercular groove of \n humerus \n
action
extension, adduction, and \n medial rotation of arm
Rhomboid minor
origin
ligamentum nuchae; spinous \n processes of vertebrae C7 and T1 \n
insertion
medial border of scapula
action
retracts scapula; elevates \n scapula; inferior rotation of \n scapula
Rhomboid major
origin
spinous processes of vertebrae of T2- \n T5 \n
insertion
medial border of scapula
action
retracts scapula; elevates \n scapula; inferior rotation of \n scapula
Deltoid
origin
lateral third of clavicle; acromion \n process; spine of scapula \n
insertion
deltoid tuberosity of humerus
action
anterior fibers: medial rotation \n and flexion of arm \n middle fibers: abduction of arm \n posterior fibers: lateral rotation \n and extension of arm
Subscapularis
origin
subscapular fossa of scapula \n
insertion
lesser tubercle of humerus \n
action \n adduction and medial rotation of \n arm
Supraspinatus
origin
supraspinous fossa of scapula \n
insertion
greater tubercle of humerus \n
action
abduction of arm
Infraspinatus
origin
Infraspinous fossa of scapula \n
insertion
greater tubercle of humerus \n
action
lateral rotation of arm
Teres minor
origin
lateral border of scapula \n
insertion
greater tubercle of humerus \n
action
lateral rotation of arm
Teres major
origin
inferior angle of scapula \n
insertion
medial lip of intertubercular \n groove of humerus
action
extension, adduction, and \n medial rotation of arm
Rectus abdominis
origin
pubic crest; pubic symphysis \n
insertion
xiphoid process; costal \n cartilages of ribs 5-7
action
flexion of vertebral column; \n stabilizes pelvis during walking; \n increases intraabdominal \n pressure during forced expiration
External oblique
origin
external surfaces of inferior eight \n ribs
insertion
linea alba; pubic crest; pubic \n tubercle; iliac crest
action
rotation and lateral flexion of \n trunk; increases intraabdominal \n pressure during forced expiration
Internal oblique
origin
thoracolumbar fascia; inguinal \n ligament; costal cartilages of \n inferior six ribs; iliac crest
insertion
linea alba; pubic crest \n
action
increases intraabdominal \n pressure during forced expiration
Erector spinae
action \n iliac crest; posterior surface of \n sacrum; processes of cervical, \n thoracic, and lumbar vertebrae \n
insertion
ribs and transverse processes of \n vertebrae about 6 segments \n above origin
action
extension and lateral flexion of \n vertebral column and neck
Quadratus lumborum
origin
iliac crest; iliolumbar ligament
insertion
inferior border of 12th rib and \n transverse processes of lumbar \n vertebrae
action
lateral flexion of vertebral \n column
External intercostals
origin
inferior border of superior rib \n
insertion
superior border of inferior rib \n
action \n elevates the ribs during normal \n inspiration
Internal intercostals
origin
superior border of inferior rib \n
insertion
inferior border of superior rib \n
action
depresses the ribs during forced \n expiration
Diaphragm
origin
xiphoid process; lower six costal \n cartilages; anterior surface of lumbar \n vertebrae L1-L3
insertion
central tendon of diaphragm \n
action
flattens to increase the volume \n of the thoracic cavity