77 terms

head and neck part II

aortic arch remodeling
right laryngeal nerve under subclavian artery and left under aortic arch; the right 6th aortic arch degenerates; left gets trapped by ligamentus arterosis
somitomeres associated with pharyngeal arches
arches 1,2,3,4; sensory is trigeminal and glossopharyngeal 1,3,4; taste is facial, glossopharyngeal and vagus 2,3 4
thyroid gland during development
from the foramen cecum; migrates while maintaining connection to the foramen cecum by the thyroglossal duct
thyroid issues
ectopic thyroid tissue, thyroglossal cysts; all on midline
development of the face
mandibular promience faithfully forms Mekle's cartilage, maxillary trying to fuse but frontonasal prominence intervenes
driving force of frontonasal prominence
forebrain cells are migrating and split eyefield and drive frontonasal prominence
development of palate
wedge of palate from frontonasal prominence; large outer part from maxillary prominence
pharyngeal arch 1 nerve
trigeminal nerve
pharyngeal arch 2 nerve
facial nerve
pharyngeal arch 3 nerve
glosspharyngeal nerve
pharyngeal arch 4 nerve
pharyngeal arch 6 nerve
pharyngeal arch 1 boney derivatives
maxillary, zygomatic, temporal, mandible, malleus, incus
pharyngeal arch 2 boney derivatives
stapes, styloid process, hyoid bone (lesser horn and upper body)
pharyngeal arch 3 boney derivatives
hyoid (lower body and greater horn)
pharyngeal arch 4 boney derivatives
upper portion of thyroid cartilage
pharyngeal arch 6 boney derivatives
lower portion of thyroid cartilage and cricoid cartilage
pharyngeal arch 1 muscle derivatives
mastication muscles, mylohyoid, anterior belly of digastric, tensor tympani, tensor palatine muscle
pharyngeal arch 2 muscle derivatives
facial expression muscle, posterior belly of digastic, stylohyoid, stapeus
pharyngeal arch 3 derivatives
stylopharengus muscle
pharyngeal arch 4 muscle derivatives
cricothyroid, levator palatine; pharyngeal constrictors; intrinsic larynx
pharyngeal arch 6 muscle derivatives
cricithyroid, levator palatine, pharyngeal constrictors, intrinsic larynx
pharyngeal cleft 1
forms external auditory; ectoderm and endoderm fusion of 1st pouch to 1st cleft become external part of TM
pharyngeal pouch 1
forms inner tympanic cavity and auditory tube
pharyngeal pouch 2
palatine tonsil
pharyngeal pouch 3
inferior parathyroid gland
pharyngeal pouch 4
superior parathyroid gland
what goes through internal auditory meatus
CN VII, CN VIII and Labyrinthine artery
structure of inner ear
chochlea with endolymph and hair cells; perilymph in contact with footplate of stapes; semicircular canals, utricle, saccule make up vestibular system; vestibule is boney space filled with perilymph
external ear structure
pinna and external ear cartilage; designed for collection of sound waves; canal is s shaped
middle ear structure
tegmen tympani is boney rood of cavity and is thin; oval window is membrane covered and stapes receives vibrations from it; promontory is boney buldge b/w two windows; round window has membrane that prevents sound waves from echoing out of inner ear; jugulum is floor right above the formation of internal jugular vein
middle ear bones
malleus, incus and stapes are in contact with each other and amplify outside sound by 30 dB
eustacean tube
links pharynx to middle ear; in children tube is shorter and more horizontal making them more prone to infection; in adults prevents pressure gradient from forming and usually closed
tensor tympani
protective mechanism for high intensity sound; attached to malleous and pulls on TM reducing amplification of memebrane; mandibular of CN V
innervated by VII and pulls on satpes and reduces amp of vibration; more effective than tensor tympani
outer layer of eyeball
sclera is tough fibrous structure where tendons insert; cornea is out layer infront of iris that is transparent
middle layer of eyeball
iris is made of smooth muscle and pigmen; ciliary muscle; choroid is vascularized middle layer of eye
fovea in center of macula
greatest density of cones gives best visual acuity
optic disc
where nerve fibers come to exit; blind spot where there are no recepts
central artery of the retina
only artery to retina; rides along with optic nerve
subarachnoid space in eye
because optic nerve is an extension of brain; it has a subarachnoid space
canal of schlemm
in anterior chamber; reabsorbs aqueous humor;
ciliary processes
secrete aqueous humor into posterior chamber where it travels through iris to anterior champer
vitreous body
fluid in rest of eye not constantly being turned over; behind the lens
distant vision
suspensory ligaments pull lens against its recoil so it decreases refraction
near vision
accommodation; contraction of ciliary muscle pulls on suspensory ligaments and causes the lens to thicken and increase refraction; problem with old age
superior opthalamic vein
an emissary vein that drains face and orbit into cavernous sinus
palpebral conjuctiva
on eyelid; helps lubricate eye
bulbar conjunctiva
on surface of cornea
superior rectus
elevation and adduction of eye
levator palprae superioris
elevation of upper eyelid
inferior rectus
depression and adduction of eye
medial rectus
adduction of eye
lateral rectus
abduction of eye
superior oblique
depression and abduction of eye; when working with inferior rectus depression
inferior oblique
elevation and abduction of eye; when used with superior rectus elevation
internal carotid and external carotid
anastomosis b/w them and blood normally flows out of orbit; if there is an occlusion blood flow changes direction and flows into orbit
veinous drainage in face
superior opthalmic vein drains into cavernous sinus; inferior opthalmic vein drains into pterygoid plexus
area of bone where middle menigeal artery is; made of temporal, frontal, parietal and sphenoid bones
upper cavity of TMJ
translation allows for protrusion/retrusion and medial lateral movements
lower cavity of TMJ
hinge movements allow for elevation/depression b/w condyle and mandible and meniscus
movement of TMJ
disc and condyle move together by lateral pterygoid is attached to both disc and condyle
origin of temporalis
temporal fossa and tempral fascia
insertion of temporalis
coronoid process of mandible
actions of temporalis
elevation and retrusion of mandible
origin of masseter
zygomatic arch
insertion of masseter
lateral aspect of angle and ramus of mandible
action of masseter
elevation and protrusion of mandible
origin of lateral pterygoid
infratemopral surface of greater wing of sphenoid, lateral surface of lateral pterygoid plate
insertion of lateral pterygoid
neck of mandible, articular disc and capsule
action of lateral pterygoid
bilateral: protrusion of mandible and depresses chin; unilateral: alternate contraction produces side to side movements
origin of medial pterygoid
medial surface of lateral pterygoid plate
insertion of medial pterygoid
medial aspect of the angle of ramus
action of medial pterygoid
elevation and protrusion of mandible
dislocation of jaw
mouth is opened widely opened and disc and condyle are at the apex of the tubercle, if it crosses apex to anterior side->dislocation and patient cannot close mouth
venous drainage of infratemporal fossa
deep facial vein connects the facial vein to the pterygoid venous plexus which connects to the cavernous sinus and indirectly to cavernous sinus by inferior opthlamic vein; pterygoid vein plexus also communicates with external jugular vein via maxillary and retromandibular veins