HUBS2103 Neural & Visceral Anatomy: Neck

Vocabulary practice flashcards covering the anatomical boundaries, compartments, fascial layers, musculature, vascular supply, and cranial and spinal nerves of the neck from Lecture 20 (HUBS2103).

Anterior Boundary of the Neck

The anatomical limit extending from the lower border of the mandible down to the manubrium of the sternum.

Posterior Boundary of the Neck

The anatomical limit extending from the superior nuchal line down to the intervertebral disc between cervical vertebra VII and thoracic vertebra I.

Visceral Compartment

The anterior single compartment of the neck enclosed by pretracheal fascia, containing the trachea, esophagus, larynx, and thyroid gland.

Vertebral Compartment

The posterior single compartment of the neck enclosed by prevertebral fascia, containing the cervical vertebrae and associated postural muscles.

Vascular Compartments

The paired lateral compartments of the neck enclosed within the carotid sheath, each containing the common carotid artery, internal carotid artery, internal jugular vein, and vagus nerve ($\text{CN X}$).

Sternocleidomastoid Muscle (SCM)

The major muscular landmark that separates the anterior and posterior compartments (triangles) of the neck; produces unilateral head rotation and bilateral flexion to draw the head forward, innervated by the accessory nerve ($\text{CN XI}$).

Thyroid Gland

A large two-lobed endocrine gland situated in the visceral compartment and anterior triangle, lying lateral to the thyroid cartilage, responsible for regulating metabolism and calcium homeostasis.

Goiter

An enlargement of the thyroid gland, typically caused by a dietary lack of iodine.

Platysma

A broad, thin sheet of muscle in the superficial fascia of the anterior neck classified as a muscle of facial expression; innervated by the facial nerve ($\text{CN VII}$).

Hyoid Bone

A U-shaped bone in the anterior neck consisting of a body and two arms (greater and lesser horns); does not articulate directly with any other skeletal element and provides attachment points for numerous head and neck muscles.

Digastric Muscle (Anterior Belly)

A suprahyoid muscle innervated by the mandibular division of the trigeminal nerve ($V_3$) that lowers the mandible and raises the hyoid bone.

Digastric Muscle (Posterior Belly)

A suprahyoid muscle innervated by the facial nerve ($\text{CN VII}$) that pulls the hyoid bone upward and backward.

Stylohyoid Muscle

A suprahyoid muscle innervated by the facial nerve ($\text{CN VII}$) that pulls the hyoid bone backward.

Mylohyoid Muscle

A suprahyoid muscle innervated by the mandibular division of the trigeminal nerve ($V_3$) that elevates the hyoid bone; forms the floor of the oral cavity together with the geniohyoid.

Geniohyoid Muscle

A suprahyoid muscle innervated by a $C1$ spinal nerve branch via the hypoglossal nerve ($\text{CN XII}$); pulls the hyoid forward when the mandible is fixed, or pulls the mandible downward when the hyoid is fixed.

Sternohyoid Muscle

An infrahyoid muscle innervated by $C1\text{--}C3$ via the ansa cervicalis that depresses the hyoid bone after swallowing.

Omohyoid Muscle

A two-bellied infrahyoid muscle innervated by $C1\text{--}C3$ via the ansa cervicalis that depresses and fixes the hyoid; the only hyoid muscle that traverses both the anterior and posterior compartments of the neck.

Thyrohyoid Muscle

An infrahyoid muscle innervated by $C1$ via the hypoglossal nerve ($\text{CN XII}$); depresses and fixes the hyoid bone and raises the larynx during swallowing.

Sternothyroid Muscle

An infrahyoid muscle innervated by $C1\text{--}C3$ via the ansa cervicalis that draws the larynx downward.

External Carotid Artery Branches

The arterial branches supplying the face and skull, ordered in ascending sequence: superior thyroid, ascending pharyngeal, lingual, facial, occipital, posterior auricular, maxillary, and superficial temporal arteries.

Glossopharyngeal Nerve (CN IX)

A cranial nerve exiting via the jugular foramen; provides motor innervation to the stylopharyngeus muscle and sensory innervation to the pharynx and carotid sinus.

Vagus Nerve (CN X)

A cranial nerve exiting through the jugular foramen and descending within the carotid sheath; provides motor fibers to the pharynx and larynx, and sensory innervation to the carotid sinus.

Accessory Nerve (CN XI)

A cranial nerve exiting via the jugular foramen; traverses both anterior and posterior triangles to provide motor innervation to the sternocleidomastoid and trapezius muscles.

Hypoglossal Nerve (CN XII)

A cranial nerve exiting through the hypoglossal canal; provides somatic motor supply to all extrinsic and intrinsic muscles of the tongue except the palatoglossus.

Ansa Cervicalis

A nerve loop of cervical origin comprising a superior root ($C1$ fibers traveling with the hypoglossal nerve) and an inferior root ($C2\text{--}C3$ fibers); provides motor innervation to the omohyoid, sternohyoid, and sternothyroid muscles.

Boundaries of the Posterior Triangle

The lateral neck space bounded anteriorly by the posterior margin of the sternocleidomastoid, posteriorly by the anterior margin of the trapezius, superiorly by the occipital bone, and inferiorly by the clavicle.

Trapezius Muscle

A large posterior neck and shoulder muscle innervated by the accessory nerve ($\text{CN XI}$) that rotates the scapula during abduction of the humerus.

Splenius Capitis

A deep muscle in the floor of the posterior triangle that acts to draw the head backward bilaterally and produce unilateral head rotation.

Levator Scapulae

A muscle located in the floor of the posterior compartment of the neck that functions to elevate the scapula.

Scalene Muscles (Anterior, Middle, Posterior)

Muscles situated in the floor of the posterior compartment of the neck that function collectively to elevate the ribs during respiration.

External Jugular Vein

A superficial vein formed by the posterior auricular and retromandibular veins that drains blood from the face and skull, crosses over the sternocleidomastoid muscle, and enters the subclavian vein.

Brachial Plexus Roots in the Neck

Nerve roots derived from the anterior rami of spinal nerves $C5\text{--}C8$ and $T1$ that emerge into the posterior neck between the anterior scalene and middle scalene muscles.