The neck Flashcards
Platysma OINA
O- depresses mandible and tenses skin of lower face and neck
N- CN VII facial n; use to express sadness, horror, fright. Also used in violent deep inspirations
Sternocleidomastoid OINA
O- anterior manubrium and superior medial 1/3 of clavicle
I- lateral mastoid process and lateral half of superior nuchal line
N- CN XI spinal accessory nerve
A- unilaterally: tilts head to its own side, rotates head; bilaterally- extends atlanto-occipital joint; flexes neck
- Torticollis or Wry neck
- occurs as a result of injury during breech presentations during child birth
Trapezius OINA
O- superior nuchal line, external occipital protuberance, spinous processes of C7-T12
I- lateral 1/3 of clavicle, acromion, spine of scapula
N- CN XI spinal accessory nerve
A- superior fibers extend (hyperextend) neck
Anterior & posterior triangles of neck
- the sternocleidomastoid divides the side of neck into two triangle
- swellings and other lesions of neck are described with reference to these cervical triangles
Splenius Capitis OINA
O- nuchal ligament and spinous process of lower cervical and upper thoracic vertebrae
I- mastoid process and nuchal line
N- posterior rami middle of cervical spinal nerves
A- laterally bends (flexes) and rotates head and neck to same side; acting together they extend the neck and the head.
Levator scapulae OINA
O- transverse process of C1-C4 I- superior part of medial border of scapula N- dorsal scapular nerve and C3 & C4 A- unilaterally flelxes neck laterally bilaterally extends/hyperextends neck
Posterior Scalene
O- transverse process of C4-C6
I- external border of 2nd rib
N- C7 & C8
A- flexes neck laterally’ elevates 2nd rib
middle scalene
O- transverse process of C3-C7
I- superior surface of 1st rib
N- anterior rami of cervical spinal nerve
A- flexes neck laterally; elevates 1st rib
anterior scalene
O- transverse process of C3-C6
I- 1st rib
N- C4-C6
A- elevates 1st rib; laterally flexes and rotates neck
digastric
O- anterior belly- inner surface of anterior mandible; posterior belly- mastoid notch (on medial surface of mastoid process on temporal bone)
I- intermediate tendon to body and greater horn of hyoid bone
N- anterior belly- CN V3 manidbular n; posterior belly- CN VII facial n.
A- depresses mandible, raises hyoid and steadies it during speaking and swallowing
mylohyoid
O- mylohyoid line of mandible
I- median Raphe and body of hyoid bone
N- CN V3 mandibular n
A- elevates hyoid, floor of mouth & tongue during swallowing & speaking
geniohyoid
O- inferior mental spine of mandible (deep to the mylohyoid)
I- body of hyoid bone
N- central ramus of C1
A- pulls hyoid bone anteriorly/superiorly’ shortens floor of mouth; widens pharynx
stylohyoid
O- styloid process of temporal bone
I- body of hyoid bone
N- CN VII facial nerve
A- elevates & retracts hyoid bone, thereby elongating mouth
sternohyoid
O- manubrium of sternum and medial end of clavicle
I- body of hyoid bone
N- C1-C3 via ansa cervicalis
A- depresses hyoid bone after it has been elevated during swallowing
Omohyoid
O- superior border of scapula near suprascapular notch
I- inferior border of hyoid bone
N- C1-C3 via ansa cervicalis
A- depresses, steadies, retracts hyoid bone
sternothyroid
O- posterior surface of manubrium of sternum
I- oblique line of thyroid cartilage
N- C2-C3 via ansa cervicalis
A- depresses thyoid cartilage
thyrohyoid
O- oblique line of thyroid cartilage
I- inferior body of greater horn of hyoid bone
N- C1 via hypoglossal nerve
A- depresses hyoid bone and elevates thyroid cartilage
Longus Colli
O- anterior bodies of cervical & upper thoracic vertebrae
I- transverse processes of C3-C6
N- C2-C6
A- bilaterally flexes neck; unilaterally rotates neck
longus capitis
O- occipital bone
I- transverse process of C3-C6
N- C1-C3
A- bilaterally flexes head; unilaterally rotates head
Rectus capitus anterior
O- lateral mass of atlas
I- basilar part of occipital bone
N- C1& C2
A- flexes atlanto-occipital joint
Rectus capitus lateralis
O- transverse process of atlas
I- lateral occipital bone
N- C1& C2
A- flexes atlanto-occipital joint; stabilizes the head
Transverse ligament rupture on atlas C1 vertebrae
- dens can be driven into spinal cord causing quadriplegia, or into medulla, causing sudden death.
- transverse ligament of atlas connects to tubercles for transverse ligament of atlas
- neck injuries are potentially serious because of possibility of fracture vertebrae, compression, or transection of cord and dislocations
Hyoid bone function
- to raise and lower larynx
- to provide stable platform for tongue
cervical plexus
- formed from ventral rami of C1-C5
- is found deep to sternocleidomastoid
- innervates: skin of neck, infrahyoid muscles, diaphragm
Contents of carotid sheath
- internal jugular v.
- common carotid a.–> internal & external carotid aa.
- carotid sinus- monitors blood pressure
- carotid body- monitor oxygen
- vagus n.
- glossopharyngeal n.
suprahyoid muscles
- stylohyoid
- digastric- posterior & anterior belly
- mylohyoid
- geniohyoid
Trigeminal and facial nerve
- mandibular divison of trigeminal
- anterior belly of digastric
- mylohyoid - facial nerve
- posterior belly of digastric
- stylohyoid
Trigeminal and facial nerve
- mandibular divison of trigeminal
- anterior belly of digastric
- mylohyoid - facial nerve
- posterior belly of digastric
- stylohyoid
Infrahyoid muscles are?
- they are called the strap muscles
1. sternohyoid
2. omohyoid
3. sternothyroid
4. thyrohyoid
Infrahyoid muscles are?
- they are called the strap muscles
1. sternohyoid
2. omohyoid
3. sternothyroid
4. thyrohyoid - all depress the hyoid bone and larynx
skeleton of the larynx
9 cartilages
- thyroid
- cricoid
- epiglottic
- arytenoid (2)
- corniculate (2)
- cuneiform (2)
Innervation of some hyoid muscles
- 4 infrahyoid, 1 suprahyoid muscles innervated by cervical spinal nerves
- C1: geniohyoid & thyrohyoid (superior muscles)
- C2&C3: sternothyroid (inferior muscle)
- C1-C3: are sternohyoid & omohyoid (cover largest distance)
