Neck Muscles Flashcards
Sternocleidomastoid
O:
Sternal head: anterior surface of manubrium
Clavicular head: superior surface of middle 1/3 of clavicle
I:
Lateral surface of mastoid process
Lateral 1/2 of superior nuchal line
A:
Unilaterally–> laterally flexes neck and rotates head superiorly and to opposite side
Bilaterally–> flexes neck
N:
Spinal Accessory N (CN XI) and Cervical n C2, C3
Platysma
O:
Fascia and skin over pec major and deltoid
I:
Inferior border of mandible and skin of lower face
A:
Tenses skin of neck
Draws corner of mouth inferiorly
Assist in depressing mandible
N:
Cervical branch of facial n (CN VII)
Splenius Capitus
O:
Inferior 1/2 of ligamentum nuchae and spinous process of T1-T6
I:
Lateral aspect of mastoid process and lateral 1/3 of superior nuchal line
A:
Unilaterally–> lateral flexion and rotation of head and neck to the same side
Bilaterally–> extension of the neck
N:
Dorsal rami of middle cervical spinal nn
Posterior Scalene
O:
Posterior tubercles of TP of C4-C6
I:
External border of second rib
A:
Flexes neck laterally
Elevates 2nd rib during forced inspiration
N:
Ventral rami of cervical spinal nn C7,C8
Middle Scalene
O:
Posterior tubercles of TP of vertebrae C2-C7
I:
Superior surface of 1st rib, posterior to groove of subclavian artery
A;
Flexes neck laterally and elevates first rib during forced inspiration
N:
Ventral rami of cervical spinal nerve C3-C8
Anterior Scalene
O:
Anterior tubercles of TP of C3-C6
I:
Scalene tubercle of inner border of 1st rib and near groove of subclavian artery
A:
Flex neck forward and laterally
Laterally rotates to opposite side
Elevates 1st rib during forced inspiration
N:
Ventral rami of cervical spinal n C4-C6
Myohyoid
O:
Mylohyoid line of mandible
I:
Midline raphe and body of hyoid bone
A:
Elevates hyoid bone, floor of mouth and tongue during swallowing and speaking
N:
Nerve to mylohyoid–branch of inferior alveolar n CN V3
Geniohyoid
O:
Inferior mental spine of mandible
I:
Body of hyoid
A:
Pulls hyoid anteriorly, shortening the floor of the mouth and widening the pharynx
N:
C1 via the hypoglossal nerve CN XII
Stylohyoid
O:
Styloid process of temporal bone
I:
Body of hyoid
A:
Elevates and retracts hyoid bone, elongating floor of mouth
N:
Cervical branch of facial nerve CN VII
Digastric
O:
Anterior belly–digastric fossa of mandible
Posterior belly–mastoid notch of temporal bone
I:
Intermediate tendon to body and greater horn of hyoid bone
A:
Depresses mandible
Raises hyoid and steadies it during swallowing and speaking
N:
Anterior belly–N to mylohyoid (branch of inferior alveolar n CN V3)
Posterior belly–cervical branch of facial nerve CN VII
Sternohyoid
O:
Manubrium of sternum and medial end of clavicle
I:
Body of hyoid bone
A:
Depresses hyoid bone after it has been elevated for swallowing
N:
C1, C2, C3 from ansa cervicalis
Sternothyroid
O:
Posterior surface of manubrium of sternum
I: Oblique line of thyroid cartilage
A:
Depresses hyoid bone and larynx
N:
C2, C3 from ansa cervicalis
Thyrohyoid
O:
Oblique line of thyroid cartilage
I: Inferior border of body and greater horn of hyoid
A:
Depresses hyoid bone and elevates larynx
N:
C1 via hypoglossal n CN XII
Omohyoid
O:
Superior border of scapula near suprascapular notch
I:
Inferior border of hyoid bone
A:
Depresses, retracts and steadies hyoid bone
N:
C1, C2, C3 from ansa cervicalis
Longus Colli
O:
Bodies of T1-T3
TP of C3-C6
I:
Anterior tubercle of C1 and bodies of C2, C3
A:
Flexes neck forward
Upper fibers laterally flex the neck
Lower fibers rotate neck to opposite side
N:
Ventral rami of C2-C6
