muscles and triangles in neck; thyroid, pharynx, and larynx

infrahyoid muscles

thyrohyoid (sternothyroid and hyoid bone)
omohyoid (has superior and inferior belly)
sternohyoid (deep to omohyoid)
sternothyroid (deep to sternohyoid)

suprahyoid muscles

mylohyoid (deep to digastric)
geniohyoid (deep to mylohyoid)
stylohyoid (styloid process to hyoid)
digastric (has anterior and posterior belly)

triangles in anterior triangle

submental
submandibular
carotid
muscular

triangles in posterior triangle

occipital triangle
supraclavicular

sternocleidomastoid muscle

big muscle in neck- attaches sternum to mastoid

posterior triangle borders

anterior: sternocleidomastoid
posterior: trapezius
inferior: clavicle
superior: apex- SCM and trapezius meeting

inferior belly of omohyoid separates occipital triangle from supraclavicular triangle

anterior triangle borders

anterior: median center line (midline)
posterior: sternocleidomastoid
superior: lower border of mandible
inferior: apex, meeting of SCM and midline (on sternum)

thyroid gland

largest endocrine gland spanning from C5 to T1 beneath the sternohyoid and sternothyroid muscles with fibrous capsule directly adhered
regulates metabolism with thyroxin (T4) and calcium with calcitonin (T3)
has right and left lobes with isthmus connecting them
part of population has an extra lobe-pyramidal lobe

parathyroid gland

four small glands on posterior surface of thyroid. produces parathyroid hormone (PTH) to help with calcium metabolism

pharynx

nasopharnyx: acts as air passageway that gets closed off by uvula and soft palate when swallowing. where pharyngeal tonsil and eustachian tubes are found

oropharynx (fauces): common food and air passageway. where palatine and lingual tonsils are found

laryngopharynx (hypopharynx): common food and air passageway. intersects with trachea, where epiglottis is found

larynx functions

provide open airway
route food and air into proper tubes (epiglottis)
voice production (vocal folds)

several cartilages are here (thyroid, cricoid, and arytenoid)

epiglottis

flap of elastic cartilage that shuts off larynx and trachea from incoming food

deglutition: swallowing

vocal folds

true vocal cords that vibrate with air from lungs. space between is rima glottidis. vestibular folds are the false vocal cords.