701: Larynx, thyroid, and parathyroid glands

thyroid gland

what is the largest endocrine gland in the body?

platysma m.
sternothyroid m.
sternohyoid m.

what 3 muscles must be reflected to view the thyroid gland?

cricothyroid m.

the thyroid gland lies posterior to all these muscles except:
-platysma m.
-cricothyroid m.
-sternothyroid m.
-sternohyoid m.

T3 (tri-iodothyronine)
T4 (thyroxine)
calcitonin

what hormones do the thyroid gland produce?

T3, T4

hormone that regulates metabolism:

calcitonin

hormone that regulates calcium levels:

carotid sheath containing common carotid a, internal jugular v, and vagus n.

the thyroid lies medial to what structure?

isthmus

the right and left lobes of the thyroid gland is connected by

trachea and esophagus

the thyroid gland is anterior and lateral to what structures?

external carotid a.

the superior thyroid artery is the 1st branch of the:

thyrocervical trunk (subclavian a.)

the inferior thyroid artery is a branch of the:

brachiocephalic trunk

the thyroid ima artery is a branch of the:

isthmus

the thyroid ima artery supplies the _______

trachea

what large structure lies directly posterior to the thyroid gland?

superior thyroid a.
inferior thyroid a.
thyroid ima a. (not in every patient)

what is the main blood supply to the thyroid gland?

recurrent laryngeal n.

what structure runs in the groove between the trachea and the esophagus?

inferior thyroid a.

patient presents with the inability to speak after a thyroid removal surgery. You know that the surgeon must have nicked the recurrent laryngeal n. What artery was the surgeon ligating when he cut the recurrent laryngeal n.?

superior thyroid v.
middle thyroid v.
inferior thyroid v.

what veins drain the thyroid gland?

internal jugular v.

the superior thyroid vein drains into the:

internal jugular v.

the middle thyroid vein drains into the:

brachiocephalic v.

the inferior thyroid vein drains into the:

thyroglossal duct (not all people still have this lobe)

the pyramidal lobe of thyroid is a remnant of

base of the tongue (foramen cecum)

that’s why some people have a pyramidal lobe of thyroid

the thyroid gland developed at the:

thyroglossal duct cyst

presents as a painless swelling in the midline near hyoid bone that moves when swallowing. What is the diagnosis?

thyroglossal duct cyst

what is the diagnosis?

Sistrunk procedure (surgical resection of duct to base of tongue including body of hyoid bone to ensure complete removal of duct)

what is the treatment for thyroglossal duct cyst?

goiter

patient presents with abnormal enlargement of the neck. Patient experiences feeling of tightness in the throat area and hoarseness. Blood screening shows a normal calcium levels and low iodine levels. What is the diagnosis?

low iodine (main)

Graves Disease, thyroiditis, thyroid cancer

what is the main cause of goiter? what are some other causes?

goiter (affects larynx)

patient presents with the following CT. What is the diagnosis?

T3 and T4 cannot be produced without iodine so thyroid releasing hormone (TRH) and thyroid stimulating hormone (TSH) become overactive causing cells in thyroid gland to hypertrophy

why does low iodine cause goiter?

goiter causing severe tracheal compression pushed to the right (breathing problems)

patient presents with the following radiograph. What is the diagnosis?

parathyroid hormone

hormones that regulates level of calcium in blood, bones, GI system

posterior

the parathyroid glands lie on the _______ aspect of the thyroid gland

4 total

2 superior, 2 inferior

how many parathyroid glands are there usually?

too much calcium in blood (kidney stones)

cancer in parathyroid glands can cause

weak muscles

removal of parathyroid glands can cause

larynx

what part of the respiratory system contains the vocal cords?

phonation (production of sound)
sphincter for respiratory system
swallowing (acts w muscles of oral cavity, oral pharynx)

functions of larynx

tip of epiglottis

upper boundary of the larynx:

lower level of cricoid cartilage

lower boundary of the larynx:

C3-C4

the epiglottis lies at what vertebral level?

C6

the cricoid cartilage lies at what vertebral level?

5-7 cm

how long is the larynx?

inferior

the larynx is located _______ to the hyoid bone

superior

the larynx is located _______ to the thyroid gland

epiglottis
thyroid cartilage
cricoid cartilage

what are the unpaired cartilages of the larynx?

arytenoid
corniculate
cuneiform

what are the paired cartilages of the larynx?

6 total

3 paired, 3 unpaired

how many cartilages make up the skeleton of the larynx?

connected by joints, membranes, ligaments

moved by muscles

the larynx cartilages are connected by…? but moved by…?

thyroid cartilage

what structure is the largest larynx cartilage and forms the Adam's apple?

thyroid cartilage

the laryngeal prominence (“Adam’s apple”) is located on which cartilage?

thyroid laminae

identify the structure:

laryngeal prominence

identify the structure:

superior thyroid notch

identify the structure:

superior horn of thyroid cartilage

identify the structure:

inferior horn of thyroid cartilage

identify the structure:

oblique line of thyroid cartilage

identify the structure:

thyrohyoid membrane

identify the structure:

cricoid membrane

identify the structure:

thyrohyoid m.
sternothyroid m.
inferior constrictor of pharynx m.

what 3 muscles attach to the oblique line of thyroid cartilage?

inferior horn of thyroid cartilage (synovial joint)

the lateral surface of the cricoid cartilage articulates with the:

cricoid cartilage

which cartilage is the 1st and only complete tracheal ring?

arytenoid cartilage (synovial joint)

the upper border of the cricoid cartilage articulates with the:

cricoid cartilage

identify the structure:

arytenoid cartilage

identify the structure:

cricoid cartilage

the arytenoid cartilages sit on the posterior aspect of the:

cricoid cartilage

the base of the arytenoid cartilage articulates with what structure?

corniculate cartilage

what structure sits on the apex of the arytenoid cartilages?

corniculate cartilage

identify the structure:

vocal process

the base of the arytenoid cartilage that give attachment to the vocal ligaments medially:

muscular process

the base of the arytenoid cartilage that give attachment to muscles laterally:

lateral cricoarytenoid m.

what muscle attaches to the muscular process of the arytenoid cartilage?

rima glottidis

the space between the vocal cords:

arytenoid cartilage

variation of the rima glottidis depends on the position of the:

False. they can slide toward/away, tilt anteriorly/posteriorly, rotate laterally/medially to bring vocal cords into abduction/adduction or to tense/relax the vocal cords$

T/F: the arytenoid cartilages are fixed on the posterior lamina.

epiglottis

identify the structure:

hyoepiglottic ligament

what connects the epiglottis to the hyoid bone:

thyroepiglottic ligament

what connects epiglottis to thyroid cartilage

vallecula

space between posterior portion of tongue and epiglottis

CN X

the taste buds located on the epiglottis are innervated by the:

piriform recess

Food passes over epiglottis and into the _______ before entering esophagus

aryepiglottic folds

this structure overlies quadrangular membrane and close off the space between epiglottis and arytenoid cartilages

cuneiform cartilage

which cartilage does not articulate with any other cartilage?

cricothyroid membrane

patient presents with the inability to breath. Everything else has been unsuccessful, but you do know the obstruction is near the vocal cords. What structure must be pierced to perform a cricothyroidotomy?

cricotracheal membrane

if you needed to perform a tracheotomy, what structure must you pierce?

quadrangular membrane

Extends between the epiglottis and the arytenoid cartilages. Its lower free edge forms the vestibular ligament

conus elasticus

Lower edge is attached to upper border of cricoid cartilage. Upper free edge forms vocal ligament

sound production

closed rima glottidis stops outflow of air

what are the functions of conus elasticus?

false vocal cords

the vestibular folds are considered the _________

true vocal cords

the vocal ligament is considered the ________

ventricle

area between true and false vocal folds

thyroarytenoid m.
vocalis m.

what two muscles form the vocal cords?

epiglottis

anterior boarder of the laryngeal inlet:

aryepiglottic folds

lateral boarder of the laryngeal inlet:

arytenoid cartilage

posterior boarder of the laryngeal inlet:

rima vestibuli

Narrow in the region of the vestibular (false) folds: