Lecture 8: Neck Flashcards
Boundaries of neck
External occipital protuberance
Tip of mastoid process
Spinous process of C7 vertebra
Acromion
Clavicle
Suprasternal notch
Inferior border of mandible
Function fo cervical vertebral column
Mobile rod of cervical vertebrae
Attachment points for muscles and fascia
Casing for vertebral artery and spinal cord
Movements of cervical vertebra
Retroflexion
Anteflexion
Sideflexion
See figure
What bones for the antlanto-occipital and the atlanta-axial joints?
AO joint: occipital bone and atlas
AA joint: Atlas and axis
See figure
Anterior pre vertebral muscles
Longus colli: Flexes neck (anterior or lateral)
Longus capitis: Flexion of head on neck (anterior or lateral)
Rectus capitis (ant,,lat.): Anterior flexes neck laterally, Lateral flexes head and stabilizes it
Lateral pre vertebral muscles
Anterior scalenus: Flexes neck laterally
Med scalenus: Flexes neck laterally
Post scalenus: Flexes neck laterally
See figure
Plastyma
Mimetic muscle of neck
Which nerve innervates the plastyma?
CN VII
Fascial layers of neck
Pretracheal layer (muscular portion)
Investing layer
Carotid sheath
Prevertebral layer
Pretracheal layer (Visceral portion)
What structures are inside the carotid sheath?
Internal carotid artery
Internal jugular vein
Vagus nerve
See figure
Anterior triangle borders
Anterior edge of sternocleidomastoid
Midline of neck
Mandible
Posterior triangle borders
Posterior border of sternocleidomastoid
Clavicle
Trapezius
See figure
Content of posterior triangle of neck
Brachial plexus
Vagal nerve
Sympathetic trunk
What muscles do the brachial plexus pass through?
The scalene muscles
Roots of brachial plexus
C5-T1
See figure
What do the brachial plexus innervate?
Shoulder and upper extremity
Succession of branches of brachial plexus
Roots -> Trunks -> Divisions -> Cords
Branches of brachial plexus
Median nerve
Ulnar nerve
Radial nerve
Biggest cranial nerve
Vagus
What does the vagus nerve innervate?
Muscles in neck
ANS system of heart, lungs, GI, liver, kidney, colon, small intestine
Ganglion of cervical sympathetic trunk
Superior, middle and inferior sympathetic ganglion
Location of cervical sympathetic trunk
On top of the anterior scalene
What does cervical sympathetic trunk innervate?
Upper extremities, head, neck, heart
Function of cervical sympathetic system
Antagonizes the parasympathetic system
Content of the anterior triangle
Hyoid bone with supra- and infra-hyoid muscles
Larynx
Thyroid gland and parathyroid glands
Suprahyoid muscles
Diastric
Stylohyoid
Genohyoid
Mylohyoid
See figure
Infrahyoid muscles
Sternohyoid
Omohyoid
Sternothyroid
Thyrohyoid
See figure
Innervation of suprahyoid
Anterior digastric: CN V3
Posterior digastric, stylohyoid: CN VII
Mylohyoid: CN V3
Genohyoid: C1
Composition of larynx
Cartilage
Ligaments
Membranes
Muscles
What are the cartilaginous laryngeal structures?
Epiglottis
Thyroid cartilage
Cricoid cartilage
2x Arytenoid cartilages
See figure
Innervation of infrahyoid muscles
Ansa cervicalis
Vestibular fold function
No role in sound production
Play protective function
Composition of vocal folds
Vocal ligament, consisting of thickened elastic tissue that is the medial free edge of the conus elasticus
Vocalis muscle, composed of exceptionally fine muscle fibers immediately lateral to and terminating at intervals relative to the length of the vocal ligaments
Glottic spaces of larynx
Supraglottic space
Transglottic space
Subglottic space
See figure
Vocal and vestibular ligaments
See figure
Which laryngeal muscles abduct the vocal cords?
Paired posterior cricoarytenoid muscles
Open the airways
All other laryngeal muscles adduct the vocal cords and close the airways
Muscles that move laryngeal cartilage
Cricothyroid muscles (lengthen vocal cords)
Posterior cricoarytenoid muscles (abduction of vocal cords)
Lateral cricoarytenoid (adduction of vocal cords)
Transverse arytenoid muscle (adduction of vocal cords)
Vocalis (shortening/ (relaxation of vocal folds)
Thyroarytenoid muscles (shortening/ relaxation of vocal folds)
Indirect laryngoscopy and positions of vocal folds
See figure
Swallowing stages and larynx
See figure
a) Food enters oral cavity, mastication and bolus formation
b) Tongue elevates and propels bolus to pharynx, soft palate elevates to seal nasopharynx
c) Larynx and hyoid bone move anterior and upward, epiglottis moves posteriorly and downwards (closes), respiration stops
d) Pharynx shortens, upper esophageal sphincter relaxes, bolus passes to esophagus
e-f) Esophageal sphincter relaxes
Bolus reaches stomach
Thyroid and parathyroid glands
See figure
Main arterial branches of thyrocervical trunk
Inferior thyroid artery
Transverse cervical artery
Suprascapular artery
Arterial blood supply of thyroid
Superior thyroid artery
Inferior thyroid artery
See figure
Venous blood supply of thyroid gland
Superior thyroid vein
Middle thyroid vein
Inferior thyroid vein
See figure
What nerve innervates all intrinsic laryngeal muscles?
Recurrent laryngeal nerve
Branch of vagus nerve
EXCEPTION: does not innervate cricothyroid muscle
What can be injured during operations of thyroid gland?
Recurrent laryngeal nerve
See figure
Blood supply of head and neck
Carotid artery
Internal jugular vein
