Posterior triangle muscles Flashcards
Platysma is found in the? (origin and insertion)
superficial fascia
sternocleidomastoid (SCM) origin
manubrium and medial clavicle
SCM insertion
mastoid process and superior nuchal line
SCM innervation
CN XI aka Spinal accessory nerve
SCM action
- acting unilaterally = laterally flexes and rotates
* acting bilaterally= posterior fibers act to extend the neck; anterior fibers act to flex the neck
SCM anterior and posterior fibers attach?
- *posterior fibers attach at superior nuchal line and clavicle AND ACT to extend the neck
- *anterior fibers attach at mastoid process and manubrium AND ACT to flex the neck
SCM stands for?
sternocleidomastoid muscle
trapezius origin
external occipital protuberance, nuchal ligament, spinous processes down to T12
trapezius insertion
lateral 1/3rd of clavicle, acromion, spine of scapula
trapezius innervation
CN XI aka Spinal accessory nerve
trapezius action
elevate, depress, and retract scapula; rotate scapula superiorly
Semispinalis capitis and Splenius capitis origin
upper thoracic and lower cerivical vertebrae
Semispinalis capitis and Splenius capitis insertion
occipital bone, between nuchal lines to mastoid process
Semispinalis capitis and Splenius capitis innervation
posterior rami of cervical nerves (Dorsal rami because deep neck)
Semispinalis capitis and Splenius capitis action
Unilateral = lateral flexion and rotation bilateral= extension of head
What two muscles are innervated by CN XI aka Spinal accessory nerve?
trapezius and sternocleidomastoid (SCM)
Levator scapulae origin
C1-C4 vertebrae
Levator scapulae insertion
medial border of scapula
Levator scapulae innervation
C3-C5 nerves
Levator scapulae action
Elevate scapula
Posterior, Middle and Anterior Scalene origin?
C2-C7 vertebrae
Posterior, Middle and Anterior Scalene insertion?
1st and 2nd ribs
Posterior, Middle and Anterior Scalene innervation?
C3-C6 nerves
Posterior, Middle and Anterior Scalene action?
Elevate ribs (inspiration) *scalene muscles are accessory muscles to the diaphragm because they help to elevate the ribs, which increase the volume in the thoracic cavity
Inferior belly of omohyoid origin
superior scapula
Inferior belly of omohyoid insertion
hyoid bone via intermediate tendon
Inferior belly of omohyoid innervation
ansa cervicalis (part of cervical plexus)
Inferior belly of omohyoid action
depresses larynx (phonation and swallowing)
What triangle is the superior and inferior belly of omohyoid found?
inferior= posterior superior= anterior
Platysma innervation?
facial nerve
Platysma action?
tenses skin of neck