Neck, Pharynx & Larynx Lecture Review

What are the superior and inferior boundaries of the neck?

Superior: inferior border of the mandible; Inferior: suprasternal notch and upper border of the clavicle.

Which muscle is enclosed by the superficial cervical fascia and what nerve innervates it?

The platysma muscle; innervated by the facial nerve (CN VII).

State three contents of the superficial cervical fascia aside from the platysma.

Cutaneous nerves of the neck, superficial veins, and superficial lymph nodes.

Name the three principal layers of the deep cervical fascia.

Investing layer, prevertebral layer, and pretracheal layer.

Which structures are surrounded by the carotid sheath?

Common/internal carotid artery, internal jugular vein, and vagus nerve (CN X).

What is the clinical importance of the retropharyngeal space?

It is the largest interfascial space in the neck and can transmit infections from the pharynx to the superior mediastinum and heart.

Which muscle divides the neck into anterior and posterior triangles?

The sternocleidomastoid (SCM) muscle.

List the superficial borders of the posterior triangle.

Posterior border of SCM, anterior border of trapezius, and middle third of the clavicle.

Name the five muscles that form the floor of the posterior triangle from superior to inferior.

Semispinalis capitis, splenius capitis, levator scapulae, middle scalene, anterior scalene.

Where is Erb’s point located and what emerges from it?

On the posterior border of SCM at its midpoint; cutaneous branches of the cervical plexus (lesser occipital, great auricular, transverse cervical, supraclavicular nerves).

Which cranial nerve supplies the SCM and trapezius?

Spinal accessory nerve (CN XI).

What causes congenital torticollis?

Birth trauma that overstretches or injures the sternocleidomastoid muscle or its nerve supply, leading to muscle shortening on one side.

Describe the course and termination of the external jugular vein.

Crosses superficially over the SCM deep to platysma and drains into the subclavian vein.

Name the two major branches of the thyrocervical trunk that appear in the posterior triangle.

Superficial (transverse) cervical artery and suprascapular artery.

Give the boundaries of the anterior triangle of the neck.

Anterior border of SCM, midline of the neck, and inferior border of the mandible; inferior apex at the jugular notch.

List the four subdivisions of the anterior triangle.

Submental, submandibular (digastric), carotid, and muscular triangles.

Which suprahyoid muscles elevate the hyoid and what are their nerves?

Mylohyoid (nerve to mylohyoid, V3), anterior digastric (nerve to mylohyoid, V3), posterior digastric (facial nerve), stylohyoid (facial nerve), geniohyoid (C1 via hypoglossal).

Which infrahyoid muscles are supplied by the ansa cervicalis?

Sternohyoid, sternothyroid, and both bellies of omohyoid.

What are the borders and a key content of the submental triangle?

Borders: anterior belly of digastric, hyoid body, mandible symphysis; contains submental lymph nodes.

Which gland and neurovascular structures lie in the submandibular triangle?

Submandibular salivary gland, facial artery and vein, and the hypoglossal nerve (CN XII).

Name the viscera found within the muscular triangle.

Thyroid gland and parathyroid glands.

Which arteries supply the thyroid gland?

Superior thyroid artery (from external carotid) and inferior thyroid artery (from thyrocervical trunk of subclavian).

Give the boundaries of the carotid triangle.

Superior belly of omohyoid, anterior border of SCM, and posterior belly of digastric.

What receptors are located at the carotid sinus and carotid body?

Carotid sinus: baroreceptor (blood pressure); Carotid body: chemoreceptor (blood O2, CO2, pH).

Name the eight branches of the external carotid artery (in order).

Superior thyroid, ascending pharyngeal, lingual, facial, occipital, posterior auricular, maxillary, superficial temporal.

Which spinal levels form the cervical plexus?

Ventral rami of C1–C4.

Where is the ansa cervicalis usually located and what does it supply?

Loops over the internal jugular vein; supplies sternohyoid, sternothyroid, and omohyoid muscles.

State the roots and surface course of the phrenic nerve in the neck.

Roots C3–C5; descends on the anterior surface of anterior scalene lateral to the internal jugular vein.

Which branch of the vagus nerve provides motor innervation to the cricothyroid muscle?

External branch of the superior laryngeal nerve.

Which nerve provides taste and general sensation to the posterior one-third of the tongue and also innervates stylopharyngeus?

Glossopharyngeal nerve (CN IX).

Describe the path of the hypoglossal nerve in the anterior triangle.

Enters deep to posterior belly of digastric, crosses between internal jugular and external carotid, gives off the superior root of ansa cervicalis, then proceeds to the floor of the mouth.

What are the three parts of the subclavian artery in relation to the anterior scalene?

First part medial to the muscle, second part posterior to it, third part lateral to it.

List the branches of the first part of the subclavian artery.

Vertebral artery, internal thoracic artery, and thyrocervical trunk (which gives inferior thyroid, transverse cervical, and suprascapular arteries).

From which structures do the right and left subclavian arteries arise?

Right: brachiocephalic trunk; Left: arch of the aorta.

Name the boundaries of the root of the neck.

Anterior: manubrium; Lateral: first ribs; Posterior: body of T1 vertebra.

Around which structures do the right and left recurrent laryngeal nerves loop?

Right loops around the subclavian artery; left loops around the arch of the aorta.

Identify the three cervical sympathetic ganglia.

Superior, middle, and inferior cervical ganglia.

Into which ducts do deep cervical lymphatics drain on the right and left sides?

Right lymphatic duct on the right; thoracic duct on the left.

Between which vertebral levels does the pharynx extend?

From the base of the skull to the level of C6 (origin of the esophagus).

Name the four layers of the pharyngeal wall from inside outward.

Mucous membrane, pharyngobasilar fascia, muscular layer, buccopharyngeal fascia.

What are the origins of the superior, middle, and inferior pharyngeal constrictors?

Superior: pterygomandibular raphe & adjacent bones; Middle: greater and lesser horns of hyoid; Inferior: thyroid and cricoid cartilages.

Which pharyngeal muscle is NOT supplied by the vagus nerve via the pharyngeal plexus?

Stylopharyngeus, innervated by glossopharyngeal nerve (CN IX).

List the three longitudinal (elevator) muscles of the pharynx.

Stylopharyngeus, palatopharyngeus, and salpingopharyngeus.

Where does the pharyngotympanic (Eustachian) tube open and what bulge does it form?

Opens into the lateral wall of the nasopharynx and forms the torus tubarius.

Which nerve supplies sensory innervation to the nasopharynx?

Glossopharyngeal nerve (CN IX).

Name the borders of the oropharynx.

Superior: soft palate; Inferior: superior border of epiglottis; Anterior: base of tongue & palatoglossal arch; Posterior/lateral walls: pharyngeal muscles with palatine tonsils.

What is a vallecula and its clinical importance?

A depression between the median and lateral glossoepiglottic folds; laryngoscope blade is placed here to lift the epiglottis during intubation.

Which nerve carries sensory fibers from the laryngopharynx?

Branches of the vagus nerve (CN X).

What is the piriform recess and its function?

A depression lateral to the laryngeal inlet; directs food toward the esophagus during swallowing.

Between which vertebral levels does the larynx lie, and to which structures is it continuous superiorly and inferiorly?

Lies opposite C4–C6; opens into laryngopharynx superiorly and continues as the trachea inferiorly.

List the unpaired and paired cartilages of the larynx.

Unpaired: epiglottis, thyroid, cricoid; Paired: arytenoid, corniculate, cuneiform.

What forms the laryngeal prominence (Adam’s apple)?

The junction of the two laminae of the thyroid cartilage.

Which cartilage is shaped like a signet ring and what are its articulations?

The cricoid cartilage; articulates superiorly with arytenoids and laterally with the inferior horns of the thyroid cartilage.

Name the two processes of the arytenoid cartilage and their attachments.

Muscular process (for cricoarytenoid muscles) and vocal process (for the vocal ligament).

How is the epiglottis attached inferiorly and superiorly?

Inferiorly to the thyroid cartilage by the thyroepiglottic ligament; superiorly to the hyoid bone by the hyoepiglottic ligament.

Which membrane connects the thyroid cartilage to the hyoid bone and what type is it?

Thyrohyoid membrane; an extrinsic ligament of the larynx.

What are the three parts of the conus elasticus?

Median cricothyroid ligament, two lateral cricothyroid ligaments, and their free superior margins (vocal ligaments).

The inferior free margin of the quadrangular membrane forms which ligament and fold?

The vestibular ligament, which forms the vestibular (false) vocal fold.

Define supraglottis, ventricle, and infraglottis.

Supraglottis: region from laryngeal inlet to vestibular fold; Ventricle: space between vestibular and vocal folds; Infraglottis: cavity from vocal folds to inferior border of cricoid.

Differentiate between the rima vestibuli and rima glottidis.

Rima vestibuli is the space between false vocal folds; rima glottidis is the space between true vocal folds.

What is the sole abductor of the vocal folds?

Posterior cricoarytenoid muscle.

State the action and innervation of the cricothyroid muscle.

Tenses/lengthens the vocal folds; innervated by the external branch of the superior laryngeal nerve (CN X).

Which muscles relax (shorten) the vocal folds?

Thyroarytenoid and vocalis muscles.

What is the main adductor of the vocal folds?

Lateral cricoarytenoid muscle (assisted by transverse arytenoid).

Which nerve supplies motor innervation to all intrinsic laryngeal muscles except the cricothyroid?

Recurrent laryngeal nerve (branch of the vagus).

Which nerves provide sensory innervation above and below the vocal folds?

Above: internal branch of superior laryngeal nerve; Below: recurrent laryngeal nerve.

Name the two arteries that supply the larynx and their parent vessels.

Superior laryngeal artery (from superior thyroid artery) and inferior laryngeal artery (from inferior thyroid artery of the thyrocervical trunk).

Loss of sensation in the nasopharynx after adenoid removal indicates injury to which nerve?

Glossopharyngeal nerve (CN IX).

Which phase of swallowing involves elevation of the larynx by mylohyoid, digastric, and thyrohyoid muscles?

Phase 2 – reflex closure of the airway during swallowing.