Dissection 8 - Neck I

Accessory n. (CN XI)

N. seen deep to SCM just inferior to ear on the anterior side of donor

Ansa cervicalis

Found within the anterior wall of carotid sheath wrapping around IJV; Loop formed by C1-3 of cervical plexus; provides SM to infrahyoid m. except for thyrohyoid

Anterior triangle

Borders: Midline of neck, SCM and omohyoid

Carotid triangle

Borders: SCM, Omohyoid, Posterior belly of digastric; Contains ansa cervicalis and ECA branchesA

Anterior scalene m.

M. that phrenic n. runs superficial to; Located deep to SCM; Fibers run inferiolaterally; The subclavian vein is anterior to the muscle, while the subclavian artery and brachial plexus are posterior to it

Common carotid a.

Located in carotid sheath, medial to IJV

Carotid body

Chemoreceptor located and bifurcation between the ECA and ICA; Innervated by CN IX

Carotid sheath

Contains CCA, CN X, and IJV; Located between pretracheal and prevertebral fascia

Carotid sinus

Baroreceptor located at the bifurcation between ECA and ICA (bulge); Innervated by CN IX

Cricoid arch

Anterior portion of cricoid cartilage

Cricoid cartilage

Cartilage located inferior to cricothyroid ligement; Has a class-ring shape

Cricothyroid m.

M. that goes from cricoid cartilage to thyroid cartilage; F: Lengthen vocal cords; I: External branch of superior laryngeal n.

Deep cervical lymph nodes

Lymph nodes located within the carotid sheath close to the IJV

Deep fascia of the neck

Part of the neck that contains the investing layer, pretrachea fascia, prevertebral fascia, and carotid sheath

External branch of superior laryngeal n. of CN X

N. that provides SM to cricothyroid m.

External jugular v.

Major vein that runs superficial to the SCM; Drains into subclavian v.F

Glossopharyngeal n.

Runs along stylopharyngus m.; Has a pharyngeal branch and a branch that innervates carotid body/sinus

Hyoid bone

Free floating bone held in place by muscles (suprahyoid and infrahyoid)

Hypoglossal n. (CN XII)

Provides SM to extrinsic and intrinsic tongue muscles; C1 hitchhikes on n. (can see C1 attaching to n. in neck of donor)

External carotid artery

Branches of CCA located outside cranium

Internal carotid artery

Branch of CCA that enters cranium via carotid canal

Internal jugular v.

Runs within the carotid sheath (deep to SCM); Drains into brachiocephalic v.

Investing layer

Layer of neck that contains trapezius and SCM

Laryngeal prominence

Adam’s apple; On thyroid cartilage (anterior point)

Lingual a.

Branch off ECA that travels deep to hyoglossus m.

Median cricothyroid ligament

Ligament between cricoid and thyroid, where a cricothyrotomy would be performed

Median thyrohyoid ligament

Ligament between thyroid and hyoid

Occipital a.

Branch of ECA that goes posteriorlyO

Omohyoid

Located deep to SCM; Has a superior and inferior belly with a tendon between and passes through a fascial sling of deep cervical fascia

Phrenic n.

Made of C3-5; provides SM and SS to diaphragm; Runs superior to anterior scalene m. and hugs the pericardium

Platysma

Thin muscle that is part of the superficial fascia

Pretracheal fascia

Part of deep fascia; Located anterior to prevertebral fascia

Puncta nervosum

Cutaneous n. derived from cervical plexus (located deep to the posterior border of the SCM)

Pyramidal lobe

Middle lobe of thyroid gland that ½ the population has

Thyroid isthmus

Midline connection between L and R lobe of thyroid gland that ½ the population has

Sternohyoid

Infrahyoid m. that runs from sternum to hyoid (over thyroid gland)

Superficial fascia

Beneath dermis, contains platysma in the neck

Superior root of ansa cervicalis

Made of C1 primarily; Runs superiorly to join hypoglossal n.

Superior thyroid a.

First branch of ECA (turns downward) and anastamoses with inferior thyroid a.

Supraclavicular n.

Branch of cervical plexus made up of C3-4 (SS only)

Thyrohyoid m.

Infrahyoid m. that runs from thyroid cartilage to hyoid; innervated by C1 hitchhiking on CN XII

Thyroid cartilage

Cartilage that lies between thyrohyoid ligament and cricothyroid ligament; contains the laryngeal prominence

Transverse cervical n.

Branch of cervical plexus made up of C2-3 (SS only)

Vagus n. (CN X)

Runs between CCA and IJV in carotid sheath and continues inferiorly; More medial the phrenic n. in thorax