muscle: origin, insertion, action

pectoralis minor

O: anterior surfaces and superior margins of ribs 3-5 or 2-4 and the fascia covering the ass. external intercostal muscles I: coracoid process of scapula A: depresses and protracts shoulder. -rotates scapula so glenoid cavity moves inferiorly. -elevates ribs if scapula is stationary

coracobrachialis

O: coracoid process i: medial margin of humerus a: adduction and flexion at shoulder

rhomboid major

O: ligamentum nuchae and the spinous processes of vertebrae T2-T5 I: vertebral border of scapula from spine to inferior angle A: adducts and performs downward rotation of the scapula

rhomboid minor

O: spinous process of C7-T1 I: vertebral border of scapula A: adducts and downward rotation of scapula

temporalis

ORIGIN: along temporal lines of skull INSERTION: coronoid process of mandible and the anterior border of the mandibular ramus ACTION: elevates mandible and closes jaws. -assists in retracting and moving mandible from side to side

masseter

ORIGIN: aponeurosis and bones of the zygomatic arch INSERTION: lateral surface and angle of mandibular ramus ACTION: elevates mandible and closes jaws. -assists in protracting and retracting mandible -move mandible side to side INTERVATION: trigeminal nerve (N V), mandibular branch

serratus posterior inferior

ORIGIN: aponeurosis from spinous processes of T11-L2 or L3 INSERTION: inferior border of ribs 9-12 ACTION: pulls ribs inferiorly and outward, opposing diaphragm

sternohyoid*

ORIGIN: clavicle and manubrium INSERTION: hyoid bone ACTION: depresses hyoid bone and larynx INNERVATION: cervical spinal nerves (c1-c3)

sternothyroid

ORIGIN: dorsal surface of manubrium and first costal cartilage INSERTION: thyroid cartilage of larynx ACTION: depresses hyoid bone and larynx

digastric anterior belly

ORIGIN: from inferior surface of mandible at chin INSERTION: hyoid bone ACTION: depresses mandible, opening mouth and or elevates larynx INNERVATION: trigeminal nerve (N V), mandibular branch

digastric posterior belly

ORIGIN: from mastoid region of temporal bone INSERTION: hyoid bone ACTION: depresses mandible, opening mouth, and or elevates larynx

geniohyoid

ORIGIN: medial surface of mandible at chin INSERTION: hyoid bone ACTION: depresses mandible, opening mouth and or elevates larynx -retracts hyoid bone

mylohyoid

ORIGIN: mylohyoid line of mandible INSERTION: median CT band (raphe) that runs to hyoid bone ACTION: elevates floor of mouth -elevates hyoid bone and or depresses mandible

thyrohyoid

ORIGIN: thyroid cartilage of larynx INSERTION: hyoid bone ACTION: depresses hyoid bone, elevates larynx

transversus abdominis

abdominal region ORIGIN: cartilages of ribs 7-12, iliac crest and thoracolumbar fascia INSERTION: linea alba and pubis ACTION: compresses abdomen

external oblique

abdominal region ORIGIN: external and inferior borders of ribs 5-12 INSERTION: external oblique aponeuroses, linea alba and iliac crest ACTION: compresses abdomen; depresses ribs; flexes, laterally flexes, or rotates vertebral column to opposite side

rectus abdominis

abdominal region ORIGIN: symphysis pubis and pubic crest INSERTION: inferior surfaces of cartilages (ribs 5-7) and xiphoid process ACTION: depresses ribs, flexes vertebral column and compresses abdomen

internal oblique

abdominal region ORIGIN: thoracolumbar fascia, inguinal ligament, and iliac crest INSERTION: inferior surfaces of ribs 9-12, costal cartilages 8-10, linea alba and pubis ACTION: compresses abdomen; depresses ribs; flexes, laterally flexes, or rotates vertebral column to opposite side -rotates vertebral column to same side

sternocleidomastoid

clavicular head: ORIGIN: attaches to sternal end of clavicle sternal head: ORIGIN: attaches to manubrium INSERTION: mastoid region of skull and lateral portion of superior nuchal line ACTION: together they flex the neck alone: rotates and extends head

buccinator

mouth ORIGIN: alveolar process of maxilla and mandible opposite the molar teeth INSERTION: blends into fibers of orbicularis oris ACTION: compresses cheeks INNERVATION: facial nerve (N VII)

RISORIUS

mouth ORIGIN: fascia surrounding parotid salivary gland INSERTION: angle of mouth ACTION: draws corners of mouth laterally

mentalis

mouth ORIGIN: incisive fossa at mandible INSERTION: skin of chin ACTION: elevates, everts, and protudes lower lip

orbicularis oris

mouth ORIGIN: maxilla and mandible INSERTION: lips ACTION: compresses, purses lips

orbicularis oculi

mouth ORIGIN: medial margin of orbit INSERTION: skin around eyelids ACTION: closes eyes INNERVATION: facial nerve (N VII)

zygomaticus major

mouth ORIGIN: zygomatic bone near the zygomaticotemporal suture INSERTION: fibers of levator anguli oris, orbicularis oris, and other muscles at angle of mouth ACTION: elevates corner of mouth and draws it laterally

serratus anterior

o: ant and sup margin of 1-8,9,or 10 i: ant surface of vertebral border of scapula a: protracts shoulder. rotate scapula so glenoid c move superiorly

pectoralis major

o: cartilages of ribs 2-6, body sternum, inferior and medial portion of clavicle i: crest of greater tubercle, lateral lip of intertubercular sulcus a: flexion, adduction, medial rotation at shoulder inn: pectoral nerves

deltoid*

o: clavicle and scapula i: deltoid tuberosity of humerus a: whole: abduction of shoulder ant: flexion and medial rotation of humerus post: extension and lateral rotation of humerus inn: axillary nerve

brachialis

o: distal half of the anterior surface of humerus i: ulnar tuberosity and coronid process a: flexion at elbow

subclavis

o: first rib i: clavicle a: depresses and protracts shoulder

infraspinatus

o: infaspinous fossa of scapula i: greater tubercle of scapula a: lateral rotation at shoulder

teres major

o: inferior angle of scapula i: lesser tubercle of humerus a: extension and medial rotation of shoulder

teres minor

o: lateral border of scapula i: greater tubercle a: lateral rotation and adduction at shoulder

trapezius

o: occipital bone, ligamentum nuchae, thoracic vertebrae i: clavicle and scapula A: depends on region: elevate, retract, depress, rotate scap upward and or clavicle. extend neck when position of shoulder is fixed Inn: accessory nerve

aconeus

o: post surface of lateral epicondyle of humerus i: lateral margin of olecranon and shaft of ulna a: extension of elbow

brachioradialis

o: r. superior to the lateral epicondyle of humerus i: lateral aspect of styloid process of radius a: flexion at elbow

brachialis brachii

o: short head from coracoid process long head from the supraglenoid tubercle i: radial tuberosity a: flexion at elbow and shoulder; supination inn: musculocutaneous nerve

latissimus dorsi

o: spinous process of inferior thoracic and all lumbar and sacral vertebrae, ribs 8-12 and thoracolumbar fascia i: floor of intertubercular sulcus of humerus a: extension, adduction, and medial rotation at shoulder

subscapularis

o: subscapular fossa of scap i: lesser tubercle a: medial rotation at shoulder

supraspinatus*

o: supraspinous fossa of scapula i: greater tubercle of humerus a: abduction of shoulder inn: suprascapular nerve

temporoparietals

scalp ORIGIN: fascia around external ear INSERTION: epicranial aponeurosis ACTION: tenses scalp, moves auricle of ear

occipitofrontalis:

scalp (epicranium) frontal belly: ORIGIN: epicranial aponeurosis INSERTION: skin of eyebrow and bridge of nose ACTION: raises eyebrows, wrinkles forehead occipital belly: ORIGIN: superior nuchal line and adjacent region of mastoid portion of the temporal bone INSERTION: epicranial aponeurosis ACTION: tenses and retracts scalp

external intercostals*

thoracic region ORIGIN: inferior border of each rib INSERTION: superior border of the more inferior rib ACTION: elevates ribs INNERVATION: intercostal nerves (branches of thoracic spinal nerves)

internal intercostals

thoracic region ORIGIN: superior border of each rib INSERTION: inferior border of the more superior rib ACTION: depresses ribs

diaphragm

thoracic region ORIGIN: xiphoid process, ribs 7-12 and ass. costal cartilages, and anterior surfaces of lumbar vertebrae INSERTION: central tendon sheet ACTION: contraction expands thoracic cavity. compresses abdominopelvic cavity INNERVATION: phrenic nerves (c3-c5)