TRIANGLES & ROOT OF THE NECK Flashcards
Boundaries of root of neck
Anterior. Manubrium and clavicles. Posterior. T1 vertebral body and superior margin of the scapula. Superior. C6 spinal level, approximately at the inferior poles of the thyroid gland. Inferior. Superior thoracic aperture.
function of the muscles of the root of the neck
support the cervical and thoracic vertebrae (longus colli), the 1st 2 ribs of the thoracic cage with the cervical vertebrae (scalene muscles), and the laryngeal apparatus with the sternum and clavicle (infrahyoid muscles).
Sternocleidomastoid (SCM) o,i,i,a,g
o:Manubrium & medial third of clavicle i:Lateral surface of mastoid process & occipital bone i: Motor:Accessory nerve (CN XI) Proprioception/Pain: C2+C3 nerves a: Bilaterally: flex head, raise thorax; Unilaterally: turns face toward opposite side g:neck
SCM deviation if accessory nerve is severed on the left
SCM is stronger on the right, so neck will deviate to the left lesion to right: neck deviates to right
Scalene (anterior) o,i,i,a,g
o:Anterior tubercles of transverse processes C3‐C6 i:Scalene tubercle on 1st rib i:Ventral rami of cervical nerves (C5‐C8) a:Elevates first rib g:Prevertebral
Scalene (middle) oiiag
O: Posterior tubercles of transverse processes C2‐C7 vertebrae I: Upper surface of first rib (behind subclavian groove) I: Ventral rami of cervical nerves (C3‐C7) A: Elevates first rib G: Prevertebral
Scalene (posterior) oiiag
O: Posterior tubercles of transverse processes C4‐C6 I: Outer surface of second rib I: Ventral rami of cervical nerves (C5‐C8) A: Elevates 2nd rib G: Prevertebral
Scalene gap and what passes thru it
the gap between the insertion of the anterior scalene and middle scalene. The subclavian artery and brachial plexus travels thru the scalene (hoagland called it the subclavian gap in class) gap. THE SUBCLAVIAN VEIN DOES NOT PASS THRU THE SCALENE GAP (but rather sits superficial to the ant scalene
Suprahyoid muscles and infrahyoid muscles
Supra hyoid : mylohyoid, digastric (ant+pst belly), stylohyoid, geniohyoid Infrahyoid: Omohyoid, sternohyoid, sternothyroid, thyrohyoid
digastric oiiag (anterior belly)
O: Digastric fossa of mandible I: Intermediate Tendon attached to body of hyoid I: Mylohyoid nerve A: Elevates hyoid and floor of mouth; depresses mandible G: Suprahyoid
digastric oiiag (posterior belly)
O: Mastoid notch of temporal bone I: Intermediate Tendon attached to body of hyoid I: Facial nerve (CN VII) A: Elevates hyoid and floor of mouth; depresses mandible G: Suprahyoid
Mylohyoid oiiag
O: Mylohyoid line of the mandible I: Median raphe & hyoid bone I: Nerve to mylohyoid (branch of inferior alveolar nerve of CN V3) A: Elevates hyoid bone & tongue when speaking & swallowing; depresses mandible (floor of mouth) G: Suprahyoid
Stylohyoid oiiag
o: Posterior border of styloid process i: Body of hyoid at junction with greater horn (slings around intermediate tendon) I: Facial nerve (CN VII) a: Elevates hyoid bone & base of tongue g: suprahyoid
Geniohyoid oiiag
o: Inferior genial tubercle of mandible I: Hyoid bone I: C1 coursing with hypoglossal nerve (CN XII) a: Elevates the hyoid bone and tongue when speaking and swallowing; depresses mandible g: Suprahyoid
Omohyoid oiiag
O: Inferior belly: from upper border of scapula via intermediate tendon I: Superior belly: to hyoid from intermediate tendon I: Ansa cervicalis A: Steadies & depresses hyoid bone G: Infrahyoid
Sternohyoid oiiag
O: Posterior surface of manubrium I: Lower border of body of hyoid I: Ansa cervicalis A: Depresses larynx & hyoid bone, steadies hyoid bone G: Infrahyoid
Sternothyroid oiiag
O: Posterior surface of manubrium I: Oblique line on lamina of thyroid cartilage I: Ansa cervicalis A: Depresses larynx & thyroid cartilage G: Infrahyoid
Thyrohyoid oiiag
O: Oblique line on lamina of thyroid cartilage I:Lower border of body & greater horn of hyoid bone I: Thyrohyoid branch of C1 via hypoglossal nerve A: Depresses larynx & hyoid bone, elevates thyroid cartilage G: Infrahyoid
Superficial fascia
superficial skin and fat contains the platysma muscle anything deep to the superficial fascia is considered deep fascia, contains the cutaneous nerves and vessels
Investing layer of deep facia
like a body stocking going all around the neck up to the skull and down to the the thorax (it surrounds the entire neck deep to superficial fascia and also surrounds the superficial layer of the cervical fascia). has a superficial and deep layer. It invests (encloses) the trapezius and SCM muscles. Keeps infections deep (so an infection will go up and down not more superficial
pretracheal layer of the deep cervical fascia
pretracheal layer is only in the anterior part of the neck, has a muscular layer and a visceral layer. Runs inferiorly from the hyoid bone to the thorax where it blends with pericardial fascia Muscular layer encloses the infrahyoid muscular group (omohyoid, sternothryroid, thyrohyoid, sternohyoid). Visceral layer encloses thyroid gland trachea+esophagus and is continuous posteriorly with the buccopharyngeal fascia which separates the esophagus from the prevertebral fascia *recurrent laryngeal nerve is located between esophagus and visceral layer.
prevertebral fascia of the deep cervical fascia
approaches the anterior tubercles of the vertebrae, contributes the posterior portion of the carotid sheath splits into Alar facia Anteriorly and continues as Prevertebral fascia Posteriorly.
Carotid Sheath
tubular, fascial investment that extends from base of skull to the root of the neck. Anteriorly it blends with the investing and pretracheal deep cervical fascia, posteriorly it blends with the prevertebral fascia. Main things in carotid sheath: IC 10 CCs in the IV (internal carotid, Vagus nerve (CN X), Common carotid, internal jugular vein). Ansa cervicalis runs along the lateral side of the carotid sheath but not inside it
Retropharyngeal space
the space located behind the pharynx bordered by the alar facia of the prevertebral fascia, buccopharyngeal and the carotid sheath. Contains the sympathatic chain. Alar fascia interdigitates with the buccopharyngeal space at T1 so the retropharyngeal space ends and contains any infections above T1. Rice crisps sound when swallowing and air is in it
