Lecture 4.4 - The Neck: Bones, Muscles, Vessel, Nerves Flashcards
What are the bones of the neck?
- C1-C7: C1 (atlas), C2 (axis)
- hyiod bone
- manubrium
- clavicles
What are the typical characteristics of a cervical vertebrae?
- transverse foramen are large; vertebral arteries pass through it
- spinous process of C3 to C6 are short and bifid; superior and inferior vertebral notches are equal in size
Which ligament prevents hyperflexion of vertebral column?
posterior longitudinal ligament
What do alar ligaments connect?
- the occipital bone.
What happens if transverse ligaments rupture?
dens can be driven into spinal cord causing quadriplegia, or into medulla causing sudden death
What do the transverse ligament of atlas connect?
connect to tubercles for transverse ligament of atlas
Why are neck injuries potentially serious?
because of possibility of fracture vertebrae, compression of transection of cord and disclocations
What are the functions of the hyoid bone?
- to raise and lower larynx
- provide stable platform for tongue
Platysma (AN)
A: depresses mandible and tenses skin of lower face and neck
N: CN VII (facial)
- it is used to express sadness, horror, or fright
- also used in violent deep inspirations (after a 200 m dash)
Sternocleidomastoid (OINA)
O: anterior manubirum and superior medial 1/3 of clavicle
I: lateral mastoid process and lateral half of superior nuchal line
N: CN XI
A: unilaterally: tilts head to its own side, rotates head; bilaterally: extends atlanto-occipital joint, flexes neck
What is Torticollis?
or wry neck
- shortened sternocleidomastoid
Trapezius (OINA)
O: superior nuchal line, external occipital protuberance, spinous process of C7-T12
I: lateral 1/3 of clavicle, acromiun, and spine of scapula
N: CN XI
A: superior fibers extend (hyperextend) neck
What is the cervical plexus formed by? What does it innervate?
- formed by ventral rami of C1-C5
- is found deep to the sternocleidomastoid
- innervates skin of neck, infrahyoid muscles, and diaphragm
Splenius Capitis (OINA)
O: nuchal ligament and spinous process of lower cervical and upper thoracic vertebrae
I: mastoid process and nuchal line
A: laterally bends (flexes) and rotates head and neck to same side; acting together they extend the neck and head
N: posterior rami of middle cervical spinal nerves
Levator Scapulae (OINA)
O: transverse process of C1-C4
I: superior part of medial border of scapula
N: dorsal scapular nerve and C1-C4
A: unilaterally flexes neck laterally; bilaterally extends/hyperextends neck
Posterior scalene (OINA)
O: transverse process of C4-C6
I: external border of 2nd rib
N: C7-C8
A: flexes neck laterally; elevates 2nd ribs
Middle Scalene (OINA)
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 (OINA)
O: transverse process of C3-C6
I: 1st rib
N: C4-C6
A: elevates 1st rib; laterally flexes and rotates neck
What are the contents of the carotid sheath?
- internal jugular vein
- common carotid artery
- internal carotid artery
- external carotid artery
- carotid sinus: monitors BP
- carotid body: monitors oxygen
- vagus n.
- glossopharyngeal n.
What are the suprahyoid muscles?
- stylohyoid
- digastric (posterior/anterior belly)
- mylohyoid
- geniohyoid
Digastric (OINA)
O: anterior: inner surface of anterior mandible; posterior: mastoid notch (on medial surface of mastoid process on temporal bone)
I: intermediate tendon to body and greater horn of hyoid bone
A: depresses mandible, raises hyoid and steadies it during speaking and swallowing
N: anterior (CN V3 mandibular), posterior (CN VII facial)
Mylohyoid (OINA)
O: mylohyoid line of mandible
I: median raphne and body of hyoid
A: elevates hyoid, floor of mouth, and tongue during swallowing and speaking
N: CN V3
Geniohyoid (OINA)
O: inferior mental spine of mandible (deep to the mylohyoid)
I: body of hyoid bone
A: pulls hyoid bone anteriorly/superiorly; shortens floor of mouth; widens pharynx
N: ventral ramus of C1
Stylohyoid (OINA)
O: styloid process of temporal bone
I: body of hyoid bone
A: elevates and retracts hyoid bone, thereby elongating mouth
N: CN VII facial
Which muscles do the mandibular division of trigeminal innervate?
anterior belly of digastric and mylohyoid
Which muscels doe the facial nerve innervate?
posterior belly of digastric and stylohyoid
What are the infrahyoid muscles?
also called strap muscles and all of the depress the hyoid and larynx
- sternohyoid, omohyoid, sternothyroid, thyrohyoid
What are the cartilages of the larynx?
9 total
- thyroid
- cricoid
- epiglottic
- arytenoid (2)
- corniculate (2)
- cuneiform (2)
Sternohyoid (OINA)
O: manubrium of sternum and medial end of clavicle
I: body of hyoid
A: depresses hyoid bone after it has been elevated during swallowing
N: C1-C3 via ansa cervicalis
Omohyoid (OINA)
O: superior border of scapula near suprascapular notch
I: inferior border of hyoid bone
A: depresses, steadies, and retracts hyoid
N: C1-C3 via ansa cervicalis
Sternothyroid (OINA)
O: posterior surface of manubrium of sternum
I: oblique line of thyroid cartilage
A: depresses thyroid cartilage
N: C2-C3 via ana cervicalis
Longus Colli (OINA)
O: anterior bodies of cervical and upper thoracic vertebrae
I: TP of C3-C6
N: C2-C6
A: bilaterally flexes neck; unilaterally rotates neck
Longus Capitis (OINA)
O: occipital bone
I: TP oc C3-C6
N: C1-C3
A: bilaterally flexes head; unilaterally rotates head
Rectus capitis anterior (OINA)
O: lateral mass of atlas
I: basilar part of occipital bone
N: C1-C2
A: flexes atlanto-occipital joint
Rectus capitus lateralis (OINA)
O: TP of atlas
I: lateral occipital bone
N: C1-C2
A: flexes atlanto-occipital joint; stabilizes the head
