Regional anatomy 2 week 3 dc

Pharynx

cavity of the throat

Larynx

cartilaginous part of the throat

Unpaired cartilage of the larynx

thyroid, cricoid, epiglottis

Thyroid cartilage

Composed of 2 quadrilateral laminae

Inferior border of each lamina projects superior and inferior as horns

Laryngeal prominence

the joining of the 2 halves of the thyroid cartilage aka "adam's apple"

Oblique line

ridge on lateral aspect of each lamina that gives attachment to sternothyroid

Cricoid cartilage

Located inferior to thyroid cartilage

Shaped like a signet ring, wider in the posterior (lamina), narrower in the anterior (arch)

What boundary is marked by the inferior border of the cricoid cartilage?

The border of the larynx and trachea

Epiglottis

Leaf shaped elastic cartilage stands vertically posterior to root of tongue and hyoid

Aspiration

food goes into lungs

Choking

something is obstructing the esophagus

Paired cartilage of the larynx

arytenoid cartilage, corniculate cartilage, cuneiform cartilage

Vocal process

directed anterior and gives attachment to the vocal ligament

Muscular process

directed laterally and gives attachment to posterior and lateral cricoarytenoid muscles

Corniculate cartilage

Located on the apex of the arytenoid cartilage

Cricothyroid joint

synovial joint between articular facets of cricoid and inferior horn of thyroid

Thyrohyoid membrane

suspends larynx from hyoid

What pierces the thyrohyoid membrane?

laryngeal nerve and superior laryngeal vessels

Hypoepiglottic and thyroepiglottic ligaments

connect the epiglottis to hyoid and thyroid

Conus elasticus

elastic membrane that extends from vocal ligaments (superiorly) to arch of cricoid (inferiorly)

Which parts of the laryngeal inlet are not innervated by branches of the vagus nerve?

cricothyroid muscle and general sensation to laryngeal inlet

Superior laryngeal nerve

innervates respiratory epithelium

Vestibular fold

false vocal fold (superior)

Vocal fold

true vocal fold (inferior) innervated by vagus nerve

Rima glottidis

space between true vocal cords

Rimu vestibuli

space between vestibular folds

Extrinsic muscles of the larynx

Suprahyoid

Infrahyoid

Pharyngeal constrictors

Intrinsic muscles of the larynx

Cricothyroid muscle

Posterior cricoarytenoid muscles

Lateral cricoarytenoid muscles

Transverse arytenoid muscles

Thyroarytenoid muscles

Vocalis muscles

Cricothyroid muscle

tense the vocal folds to control pitch

Posterior cricoarytenoid muscles

the ONLY abductors of the vocal folds

originates from the cricoid lamina and inserts into the muscular process of the arytenoid

Abducts and externally rotates the vocal folds

Lateral cricoarytenoid muscles

adduct the vocal folds

Transverse arytenoid muscles

adducts vocal folds

an unpaired muscle that attaches to the posterior surface of arytenoid, adducts the vocal folds

Thyroarytenoid muscles

relax vocal folds

originates from the thyroid lamina, relaxes the vocal fold and lowers pitch of the voice, responsible for vibration during phonation

Vocalis muscles

contraction affects frequency of vibrations and controls pitch

formed by most medial fibers of thyroarytenoid, controls pitch controls vibration during phonation

What nerve controls the majority of innervation to the laryngeal muscles?

Vagus

Posterior cricoarytenoid

originates from the cricoid lamina and inserts into the muscular process of the arytenoid

Abducts and externally rotates the vocal folds

Transverse arytenoid

an unpaired muscle that attaches to the posterior surface of arytenoid, adducts the vocal folds

What controls the major motor innervation via the superior and inferior laryngeal nerves?

Vagus nerve

Recurrent laryngeal nerve

supplies mucosa below vocal folds sensory

Superior and inferior laryngeal veins

join the superior and inferior thyroid veins

Superior thyroid vein

drains into IJV

Inferior thyroid vein

rains into the brachiocephalic vein

Thyroid gland

secretes thyroxine (T4) and triiodothyronine (T3)

2 types of cells: follicular and C cells

Regulates calcium levels in the cell via calcitonin

Foramen cecum

the point of origin of the thyroid

Thyroglossal duct

the canal that connects the tongue to the thyroid gland

Parathyroid glands

2 inferior and 2 superior

Secrete parathormone

Supplied by superior and inferior thyroid arteries

Parathyroid veins drain into thyroid venous plexus

Papillary Thyroid cancer

develops from follicular cells, grows slowly, most common type

Follicular Thyroid cancer

develops from follicular cells, grows slowly, less common

Medullary Thyroid cancer

develops in C cells

Anaplastic Thyroid cancer

develops from follicular cells