Lecture 21 - Neck Flashcards
(25 cards)
Hyoid Bone
- “floating” bone, anchored by muscles
- aids in swallowing and tongue movements
What are the three ligaments of the neck?
- Anterior longitudinal ligament
- Ligamenta flava
- Nuchal ligament
Extrinsic Muscles of the Neck
trapezius, splenius, longissimus, semispinalis, levator scapulae, scalenes
Intrinsic Muscles of the Neck
suboccipital muscles, sternocleidomastoid, longus capitus, longus colli, hyoid muscles
Suboccipital Triangle
- rectus capitus posterior major
- rectus capitus posterior minor
- oblique capitus superior
- obilque capitus inferior
Attachments: occipital bone, C1-C2
Actions: extension, lateral flexion of the neck
Innervation: suboccipital nerve
Sternocleidomastoid
Attachments: clavicle, manubrium, mastoid process
Action: flexion, lateral flexion, rotation of the neck
Innervation: CN XI
Longus capitis
Attachments: transverse processes, anterior occipital bone
Action: flexion and rotation of the head
(top arrow)
Longus colli
Attachments: transverse processes, arch of the atlas
Action: flexion and lateral flexion of the neck
(bottom arrow)
Suprahyoids
-digastric, mylohyoid, stylohyoid, geniohyoid
Action: depress and retract mandible, elevate and protract hyoid
Infrahyoids
-omohyoid, sternohyoid, thyrohyoid, sternothyroid
Action: depress/stabilize hyoid, move larynx
Arteries of the neck
brachiocephalic → common carotid → carotid sinus → external and internal carotid
Veins of the head and neck
emissary veins → sagittal, transverse and sigmoid sinuses → internal jugular (collects deoxygenated blood and discarded CSF from the brain)
outside of head → external jugular
Emissary Veins
- connect internal sinuses to external veins of scalp
- important for heat regulation in the brain
Cavernous Sinus
- drains facial veins into the cranial venous system
- surrounds pituitary gland
- deoxygenated blood wraps around artery perforation, colling venous blood (heat exchange)
Why is choking a uniquely human problem?
Changes in human face shape lead to descent of the larynx, so the epiglottis is no longer in contact with the soft palate
-this creates a retro-oropharyngeal space where food can get trapped
*not in babies
Deglutition (swallowing) Steps
- Tongue sweeps bolus back
- Hyoid slightly elevated
- Bolus swept into oropharynx, lateral arches stiffen
- Soft palate elevated/tensed
- Hyoid elevates larynx, depressing epiglottis
- Esophageal sphincter opens, pharyngeal constrictors contract, send bolus into esophagus
(1-3 voluntary, 4-6 involuntary)
Pharyngeal Constrictor Muscles
-superior, middle, inferior
Action: constrict pharynx, move food bolus
Innervation: CN X
How is sound produced in talking?
- sound is produced by forcing air through closed/tensed vocal chords
- pitch = rate of vibration
- volume = force of air
- length of vocal tract = deepness of voice
Laryngeal Cartilages
Vocal Ligaments & Muscles
- vocal ligaments: span from arytenoid cartilages to thyroid cartilages
- muscles: cricothyroid, thyroarytenoid, posterior cricoarytenoid, lateral cricoarytenoid, arytenoideus
- all muscles innervated by CN X
What is the action of the cricothyroid muscles?
Lengthens (tenses) vocal folds
What is the action of the thyroarytenoid muscles?
Shortens (relaxes) vocal folds
What is the action of the posterior cricoarytenoid muscles?
Abducts (opens) vocal folds
What is the action of the lateral cricoarytenoid muscles?
Adduct (closes) vocal folds
