Muscles That I Need to Know Flashcards
Frontal Belly of Epicranius
origin: epicranial aponeurosis; insertion: skin of eyebrow; action: raises eyebrows
Occipital Belly of Epicranius
origin: occipital and temporal bones; insertion: epicranial aponeurosis; fixes aponeurosis and pulls scalp posteriorly
Orbicularis Oculi
origin: frontal and maxilla bones; insertion: tissue of eyelid; action: closes eyelid (such as blinking, squinting and winking)
Corrugator Supercilli
origin: frontal bone; insertion: skin of eyebrow; action: draws eyebrows meidally ( as in frowning)
Zygomaticus Major and Minor
origin: zygomatic bone; insertion: skin and muscle at corner of mouth; action: elevates lateral corners of the mouth (as in smiling)
Risorius
origin: fascia of masseter muscle; insertion: skin at corner of the mouth; action: draws corners of lip laterally (tenses the lip), synergist of the zygomaticus muscles
Orbicularis Oris
origin: indirectly to maxilla and mandible; insertion: inserts into muscle and skin at corners of the mouth; action: closes lips, purses and protrudes lips (such as kissing and whistling)
Buccinator
origin: maxilla and mandible; insertion: orbicularis oris; action: compresses cheek as in whitlsting or sucking through a straw
Masseter
origin: zygomatic arch and zygomatic bone; insertion: mandible; action: primer mover of mandible elevation (as in clinching teeth)
Temporalis
origin: temporal bone; insertion: coronoid process of mandible; action: elevates and retracts mandible (synergist of masseter)
Platysma
origin: fascia of chest (over pectoral muscles and deltoid); insertion: lower margin of mandible and skin; action: tenses skin of neck (pulls lower lip back and downward as in shaving )
Sternocleidomastoid
origin: manubrium of sternum and medial calvical; insertion: mastoid process of temporal bone and occipital bone; action: simultaneous contraction of both , flexes the neck; acting independently rotates head toward shoulder on opposite side
Pectoralis Major
origin: clavical, sternum, cartilage of ribs 1-6 and aponeurosis of external oblique muscle; insertion: humerus; action: prime mover of arm flexion, adducts and medially rotates arms (also acts in forced inhalation)
Serratus Anterior
origin: lateral aspect of ribs 1-8; insertion: anterior surface of medial border of scapula; action: primer mover to abduct scapula (allows arm to be raised and deliver a punch as in boxing)
Deltoid
origin: lateral 1/3 of clavical, acromion and spine of scapula; insertion: deltoid tuberosity of humerus; action: prime mover of arm abduction
Pectoralis Minor
origin: ribs 3-5; insertion: coracoid process of scapula; action: with ribs fixed, draws scapula forward and inferior, with scapula fixed, elevates the rib cage as in forced inspiration
External Intercostals
origin: inferior border of rib above ; insertion: superior border of rib below; action: elevate rib cage, synergist of diaphragm
Diaphragm
origin: inferior border of rib and sternum, costal cartilages of last 6 ribs and lumbar vertebrae; insertion: central tendon; action: prime mover of inspiration(flattens the diaphragm which increases volume of thoracic cavity)
Rectus Abdominis
origin: pubic crest and symphysis; insertion: xiphoid process and costal cartilages of ribs 5-7; action: flexes the vertebral column (as in sit ups)