Anatomy Flashcard Muscles 10/24/2004

Front 1

Epicranius
Frontal Belly

Back 1

Origin=Galea Aponeurotica

Insertion=Skin of eyebrows and root of nose

Action=With Aponeurosis fixed, frontal belly raises eyebrows.

Front 2

Epicranius
Occipital Belly

Back 2

Origin=Occipital and Temporal Bones

Insertion=Galea Aponeurotica

Action= Fixes Aponeurosis and pulls scalp posteriorly

Front 3

Obicularis Oculi

Back 3

Origin= Frontal and Maxillary bones and ligaments around orbit

Insertion=Encircles orbit and inserts into tissue of eyelid

Action= Various parts can be activated individually, closes eyes, blinking, squinting, and draws eyebrows inferiorly.

Front 4

Obicularis Oris

Back 4

Origin= Arises indirectly from maxilla and mandible, fibers blended with fibers of other muscles associated with lips

Insertion=Encircles mouth, inserts into muscle and skin at angles of mouth

Action= Closes mouth, purses and protrudes lips,(kissing and whistling muscle)

Front 5

Buccinator

Back 5

Origin=Molar region of maxilla and mandible

Insertion=Obicularis oris

Action= Draws corners of mouth laterally, compresses cheek (as in whistling), holds food between teeth during chewing.

Front 6

Masseter

Back 6

Origin= Zygomatic arch and maxilla

Insertion= Angle and ramus of mandible

Action= Closes jaw, elevates mandible,

Front 7

Temporalis

Back 7

Origin=Temporal fossa

Insertion= Coranoid process of mandible

Action= Closes jaw, elevates and retracts mandible

Front 8

Medial Pterygoid

Back 8

Origin= Sphenoid, palatine, and maxillary bones

Insertion= Medial surface of mandible, near its angle.

Action= Synergist of temporalis and masseter, elevates mandible, in conjuction with lateral pterygoid, aids in grinding movements.

Front 9

Lateral Pterygoid

Back 9

Origin=Greater wing of sphenoid bone

Insertion= Mandibular condyle

Action= Protracts jaw, in conjunction with medial pterygoid aids in grinding movements of teeth.

Front 10

Platysma

Back 10

Origin= Fascia of chest (over pectoral muscle) and deltoid.

Insertion= Lower margin of mandible, skin, and muscle at corner of mouth.

Action= Depresses mandible, pulls lower lip back and down (downward sag of mouth)

Front 11

Sternocleoidomastoid

Back 11

Origin=Manubrium of sternum and medial portion of clavicle

Insertion= Mastoid process of temporal bone and superior nuchal line of occiptal bone

Action= Simultaneous contraction of both muscles of pair causes flexion of neck forward, generally against resistance (as when lying on the back), acting independently, rotates head toward shoulder on opposite side.

Front 12

Digastric

Back 12

Origin= Lower margin of mandible (anterior belly) and mastoid process (posterior belly)

Insertion= By a connective Tissue Loop to hyoid bone

Action= Acting in concert elevate, hyoid bone, open mouth and depress mandible.

Front 13

Pectoralis major

Back 13

Origin= Clavicle, sternum, cartilage of ribs 1-6, and Aponeurosis of external oblique muscle

Insertion= Fibers converge to insert by short tendon into intertubercular of humerous.

Action= Prime mover of arm flexion, adducts, medially rotates arm, with arm fixed pulls chest upward, thus also acts in forced inspiration.

Front 14

Serratus Anterior

Back 14

Origin= Lateral aspect of ribs 1-8

Insertion= Vertebra; border of anterior surface of scapula

Action= Moves scapula forward toward chest wall, rotates scapula, abduction and raising of arm.

Front 15

Deltoid

Back 15

Origin= Lateral 1/3 or clavicle, acromion and spine of scapula

Insertion= Deltiod tuberosity of humerous

Action= Acting as a whole, prime mover of arm adduction. When only specific fibers are active, can aid in flexion, extension, and rotation of humerus.

Front 16

Pectoralis minor

Back 16

Origin=Anterior surface of ribs, near their costal cartilages

Insertion=Coracoid process of scapula

Action=With ribs fixed, draws scapula forward and inferiorly, with scapula fixed, draws ribcage superiorly

Front 17

External Intercostals

Back 17

Origin= Inferior border of rib above

Insertion= Superior border of rib below

Action= Pulls ribs toward one another to elevate cage, aids in inspiration.

Front 18

Internal Intercostals

Back 18

Origin=Superior border of rib below

Insertion=Inferior border of rib above

Action=Draws ribs together to depress rib cage, aids in forced expiration, antagonist to external intercostals

Front 19

Diaphragm

Back 19

Origin= Inferior border of rib and sternum, costal cartilages of last six ribs and lumbar vertebra

Insertion=Central tendon

Action= Prime mover of inspiration flattens on contraction, increasing vertical dimensions of thorax, increases intra-abdominal pressure.

Front 20

Rectus abdominis

Back 20

Origin=Pubic crest and symphysis

Insertion=Xiphoid process and costal cartilages of ribs 5-7

Action=Flexes and rotates vertebral column, increases abdominal pressure, fixes and depresses ribs, stabilizes pelvis during walking, used in sit-ups and curls.

Front 21

External oblique

Back 21

Origin=Anterior surface of last eight ribs

Insertion=Linea alba, pubic crest and tubercles, and iliac crest.

Action=See rectus abdominis above. Also aids in muscles of back in trunk rotation and lateral flexion, used in oblique curls.

Front 22

Internal oblique

Back 22

Origin=Lumbar fascia, iliac crest, and inguinal ligament

Insertion=Linea alba, pubic crest, and costal cartilages of last three ribs.

Action=As for external oblique.

Front 23

Transverse abdominis

Back 23

Origin=Inguinal ligament, iliac crest, cartilages of last five or six ribs, and lumbar fascia.

Insertion=Linea alba and pubic crest

Action=Compresses abdominal contents

Front 24

Trapezius

Back 24

Origin=Occipital bone, ligamentum nuchae, spines of C7 and all thoracic vertebrae.

Insertion=Acromion and spinous process of scapula, lateral third of clavicle.

Action=Extends head, raises, rotates, and retracts (adducts) scapula and stabilizes it, superior fibers elevate scapula (as in shrugging the shoulders),inferior fibers depress it.

Front 25

Latissimus dorsi

Back 25

Origin=Indirect attachment to spinious processes of lower six thoracic vertebrae, lumbar vertebrae, last three to four ribs, and iliac crest.

Insertion=Floor of intertubercular groove of humerus.

Action=Prime mover of arm extension, adducts and medially rotates arm, depresses scapula, brings arm down in power stroke, as in striking a blow.

Front 26

Infraspinatus

Back 26

Origin=Infraspinous fossa of scapula

Insertion=Greater tubercle of humerus

Action=Lateral rotation of humerus, helps hold head of humerus in glenoid cavity, stabilizes shoulder.

Front 27

Teres Minor

Back 27

Origin=Lateral margin of scapula

Insertion=Greater tubercle of humerus

Action=As for infraspinous

Front 28

Teres Major

Back 28

Origin=Posterior surface at inferior angle of scapula

Insertion=Intertubercular groove of humerus

Action=Extends, medially rotates, and adducts humerus, synergist of latissimus dorsi.

Front 29

Supraspinatus

Back 29

Origin=Supraspinous fossa of scapula

Insertion=Greater tubercle of humerus

Action=Assists abduction of humerus, stabilizes shoulder joint

Front 30

Levatorscapulae

Back 30

Origin=Transvers process of C1-C4

Inertion=Medial border of scapula superior to spine

Action=Elevates and adducts scapula, with fixed scapula, flexes neck to the same side.

Front 31

Rhomboids major and minor

Back 31

Origin=Spinous processes of C7 and T1-T5

Insertion=Medial border of scapula

Action=Pulls scapula medially (retraction), stabilizes scapula, rotates glenoid cavity downward.

Front 32

Semispinalis

Back 32

Origin=Transverse process of C7-T12

Insertion=Occipital bone and spinous processes of cervical vertebrae and T1-T4

Action=Acting together, extends head and vertebral column, acting independently (right vs. left) causes rotation towards opposite side.

Front 33

Erector Spinae

Back 33

Origin=Iliac crest, transverse processes of lumbar, thoracic, and cervical vertebrae, and/or ribs 3-6 depending on specific part.

Insertion=Ribs and transverse processes of vertebrae about six segments above origin, longissimus also inserts into mastoid process

Action=Extend and bend the vertebral column laterally, fibers of longissimus also extend head.

Front 34

Triceps brachii

Back 34

Origin=Long head- inferior margin of glenoid cavity, lateral head-posterior humerus, medial head-distal radial groove on posterior humerus

Insertion=Olecranon process of ulna

Action=Powerful forearm extensor, antagonist of forearm flexors (brachilais and biceps brachii)

Front 35

Biceps brachii

Back 35

Origin=Short head-corocoid process, tendon of long head runs in intertubercular groove and within capsule of shouleder joint.

Insertion=Radial tuberosity

Action=Flexion (powerful) of elbow and supination of forearm, it turns the corkscrew and pulls the cork. Weak arm flexor.