Muscles Flashcards
Masseter
O: Zygomatic arch of the temporal bone
I: Angle, ramus and coronoid process of the mandible
A: Elevates the mandible at the temporomandibular joint
Protracts the mandible at the temporomandibular joint
Temporalis
O: temporal fossa
I: coronoid process and ramus of mandible
A: elevates the mandible at temporalmandibular joint
retracts the mandible at the temporomandibular joint
Frontalis
O: galea aponeurotica
I: fascia and skin overlaying the frontal bone
A: draws the scalp posteriorly (raise the eyebrows and wrinkle forehead)
draws the scalp anteriorly
Occipitalis
O: superior nuchal line of the occiput and mastoid area of the temporal bone
I: galea aponeurotica
A: draws the scalp posteriorly (anchor and retract the galea aponeurotica)
Sternocleidomastoid ‘SCM’
O:
medial clavicular, sternum
I: mastoid process of the temporal bone
lateral superior nuchal line of the occipital bone
A:
unilaterally- lateral flexion to same side, contralateral rotation opposite side
bilaterally- flexes the head and neck
*LARGEST MUSCLE IN NECK
Scalenes
O: transverse processes C2-C7
I:
anterior & middle- first rib (posterior to clavicle)
posterior- second rib (at or unders traps)
A:
unilateral: laterally flexes neck same side, rotates neck opposite side
bilaterally- flexes the neck
*NO HEAD, JUST NECK
Splenius Capitis
O: inferior ligaments nuchae and spinous processes C7-T4
I: mastoid process of the temporal bone and lateral superior nuchal lines of occipital bone
A:
unilateral: lateral head flexion, rotates head and neck to the same side
bilateral: extension
*HEAD AND NECK
Splenius Cervicis
O: spinous processes of T3-T6
I: transverse processes of C1-C3
A:
unilateral: laterally flexes neck to same side, ipsilaterally rotates neck to same side
bilaterally: extends neck
*JUST NECK
Diaphragm
O: internal surface of ribs 7-12 and their coastal cartilage, internal surface of the diploid process of the sternum and anterior vertebral bodies of L1-L3
I: central tendon (dome) of the diaphragm
A: expands the thoracic cavity when abdominal breathing
Intercostal Group
O: inferior border of one rib
I: superior border of the rib directly inferior
A: elevates the ribs at the sternocostal and costospinal joints (assist with inhalation)
Internal Intercostals
O: superior border of one rib and its costal cartilage
I: inferior border of the rib and its costal cartilage directly superior
A: depresses ribs at the sternocostal and costospinal joints (assist with exhalation)
Serratus Posterior Superior
O: inferior ligaments nuchae and spinous processes
I: superior, external surfaces of ribs 2-5
A: elevate ribs 2-5 (during inhalation) at the sternocostal and costospinal joints
Serratus Posterior Inferior
O: spinous processes T11-L3
I: inferior, exterior surfaces of ribs 9-12
A: depress ribs 9-12 (in exhalation) at the sternocostal and costospinal joints
Trapezius Upper Fibers
O: external occipital protuberance, super medial (one third of the) nuchal line of the occipital and ligamentum nuchae
I: posterolateral (one third of the) clavicle
A: elevates the scapula at the scapula thoracic joint
Trapezius Middle Fibers
O: SP C7-T3
I: acromion process and superior border of the scapular spine
A: adducts (retracts) the scapula at the scapulothoracic joint
Trapezius Lower Fibers
O: SP T4-T12
I: tubercle at the root of the spine of the scapula
A: depresses the scapula
upwardly rotates the scapula
adducts (retracts) the scapula
Rhomboids
O: SP C7-T5
I: medial border of the scapula from the root of the spine to the inferior angle
A: adducts (retracts) the scapula
elevated the scapula
downwardly rotates the scapula
Levator Scapula
O: TP C1-C4
I: medial border of the scapula from the superior angle to the root of the spine of the scapula
A: elevates the scapula
downwardly rotates the scapula
Serratus Anterior
O: external surfaces of the anterolateral ribs 1-9
I: anterior surface of the medial border of the scapula
A: abducts (protracts) the scapula
upwardly rotates the scapula
depressed the scapula
Pectoralis Minor
O: ribs 3-5
I: medial aspect of the coracoid process of the scapula
A: abducts (protracts) the scapula
depresses the scapula
downwardly rotates the scapula
Deltoid
O: anterior fibers- lateral (one third of the) clavicle
middle fibers- lateral acromion process of the scapula
posterior fibers- spine of scapula
I: deltoid tuberosity of the humerus
A: anterior fibers- flex the shoulder
internally rotates shoulder
horizontally adducts the shoulder
posterior fibers- extend the shoulder
externally rotates the shoulder
horizontally addicts the shoulder
Coracobrachialis
O: coracoid process of the scapula
I: medial surface of the mid-humeral shaft
A: flexes the shoulder
adducts the shoulder
horizontally adducts the shoulder
Pectoralis Major
O: clavicular fibers- anteromedial (one half) of the clavicle
sternal fibers- sternum and costal cartilage of ribs 1-9
I: crest of the greater tubercle of the humerus
A: all fibers:
adducts
internally rotates
clavicular fibers:
flex
horizontally adducts
sternal fibers:
extends
Latissimus Dorsi
O: SP T7-L5, posterior sacrum, posterior iliac crest, posterior ribs 10-12 all via thoracolumbar fascia
I: intertubecular (bicipital) groove (just on the inside of the lesser tubercle) of the humerus
A: internally rotates the shoulder
adducts the shoulder
extends the shoulder
Teres Major
O: inferior angle and inferior (one third) of the lateral border of the scapula
I: crest of the lesser tubercle of the humerus
A: internally rotates the shoulder
extends the shoulder
adducts the shoulder
