HEENT Flashcards
1
Q
function of mucous
A
aids in warming and humidifying inhaled air, traps debris, helps with olfaction
2
Q
mucous contains
A
immunoglobulins (antibodies), lysozymes, and lactoferrin (a protein that binds iron and has immunological properties making it antiviral and antibacterial)
3
Q
eustachian tubes
A
connections from the tympanic membrane (middle ear) to the nasopharynx which are normally closed but can be opened by several muscles (more horizontal at an angle of 10 degrees in children versus 45 degrees in adults)
4
Q
function of eustachian tubes
A
equalize pressure, oxygenate tympanic membrane, and drain fluid
5
Q
crista galli
A
midline upward projection above the cribriform plate of the ethmoid bone which is the attachment site for the dura mater of the meninges
6
Q
blood vessel that supplies most of the nose and mouth
A
external carotid artery which branches into facial artery
7
Q
Kiesselbach’s plexus
A
group of arteries in the anterior septal region formed from small arterial branches off of the sphenopalatine and facial arteries
8
Q
most common site for epistaxis
A
Kiesselbach’s plexus (anterior aspect of nares)
9
Q
Woodruff’s plexus
A
group of arteries in the posterior septal region formed from small arterial branches off of the sphenopalatine artery
10
Q
Bowman’s glands
A
secrete mucous onto the olfactory membrane that aids in trapping odors/chemicals which stimulate neural receptors
11
Q
olfactory epithelium contains
A
basal cells, olfactory sensory neurons, and supporting epithelial cells (sustentacular cells)
12
Q
location of olfactory bulb
A
above the cribriform plate of the ethmoid bone
13
Q
location of olfactory epithelium
A
below the cribriform plate of the ethmoid bone folding down along the nasal septum and over the superior turbinate laterally
14
Q
visceral responses to smell involve
A
the medial olfactory area (anterior to the hypothalamus) and the reticular formation
15
Q
complex responses to smell (linking to memory and emotion) involve
A
the amygdala and hippocampus
16
Q
function of paranasal sinuses
A
assist with further humidification and warming of air during inspiration, improve vocal resonance, and reduce weight of the skull
17
Q
paranasal sinuses
A
maxillary, frontal, sphenoidal, and ethmoidal
18
Q
largest of the paranasal sinuses
A
maxillary sinus
19
Q
hiatus semilunaris
A
where the maxillary and frontal sinuses connect to (and drain into) the nasal cavity
20
Q
inferior border of maxillary sinus
A
nasal cavity and teeth
21
Q
superior border of maxillary sinus
A
inferior wall of ortbit
22
Q
normal number of permanent (adult) teeth
A
32, numbered beginning from posterior upper right and ending at the posterior lower right
23
Q
normal number of primary teeth in children
A
20, labeled A-T beginning from the posterior upper right and ending at the posterior lower right
24
Q
ridges on posterior tongue
A
valate papilla
25
ridges on anterior tongue
fungiform papilla
26
posterior arch (behind uvula) in oral cavity
pharyngopalatine arch
27
palatoglossus (palatoglossal arch)
tongue muscle that is attached to the palatine aponeurosis at the top and the side of the tongue at the bottom which receives motor innervation from the pharyngeal branch of the vagus nerve instead of the hypoglossal nerve
28
most sensitive component of taste
bitter - requires the least amount of chemical to stimulate
29
sense of taste requires
chemical activation of taste buds
30
number of taste cells contained within a taste bud
100 taste cells
31
taste pore
made up of taste cells coming together with microvilli which receive chemical stimulation causing depolarization of the cell and change in electrical potential
32
nerve responsible for taste in anterior 2/3 of tongue
facial nerve
33
nerve responsible for taste in posterior aspect of tongue
glossopharyngeal nerve and vagus nerve
34
synapse pathway of taste signals carried by the facial, glossopharyngeal, and vagus nerve through the CNS
first synapse in the solitary nucleus of the medulla oblongata, then cross over and enter the medulla lemniscus of the medulla oblongata, then synapse in the thalamus, and finally, the information is projected to the gustatory cortex of the insula
35
location of taste reflexes that stimulate saliva production
within the brain stem
36
tonsils
made of lymphoid tissue and contain memory immune cells (T and B cells) and crypts that entrap and destroy bacteria which protect against inhaled or ingested pathogens
37
location of palatine tonsils
between the palatoglossal and palatopharyngeal arches
38
location of pharyngeal tonsils (adenoids)
superior and posterior to the uvula in the posterior nasopharynx attached to the sphenoid - only present in young children (reach maximal size by 3-5 years and start to shrink by 7-8 years)
39
major salivary glands
parotid, submandibular, and sublingual glands
40
type of cells that produce saliva
acinar cells
41
salivary glands are innervated by
the facial and glossopharyngeal nerves
42
glottis
opening to the trachea that lies within the larynx and contains the vocal cords (folds)
43
epiglottis
a flap of cartilage that lies above the glottis and over the trachea to protect the airway from food and fluids during swallowing
44
cricoid cartilage
inferior to thyroid cartilage and marks the end of the larynx
45
Arytenoid and Corniculate cartilages serve as
sites for attachment of muscles that regulate tension on the vocal cords and aid in closing the larynx during swallowing
46
Epiglottic cartilage attaches to
the thyroid cartilage and supports the epiglottis
47
primary function of the larynx
voice production/speech
48
function of vestibular folds (false vocal cords)
close off glottis to keep food out
49
function of vocal folds (true vocal cords)
create sound waves through vibration during exhalation when laryngeal muscles pull them across the trachea opening creating tension
50
risk factors for posterior epistaxis
comorbidities associated with the elderly including HTN, atherosclerosis, and anticoagulation
51
septal hematoma
bleeding between the perichondrium and the cartilage of the nasal septum which is usually a result of nasal trauma (occurring 24-72 hours after trauma)
52
serious complications of septal hematoma
septal necrosis and saddle nose deformity or possibly abscess formation causing nasal discomfort, obstruction, rhinorrhea, and fever
53
rhinitis symptoms
sneezing, rhinorrhea, congestion, nasal itching, and coughing
54
most common cause of rhinitis
allergies
55
atopic triad
asthma, eczema (atopic dermatitis), allergies
56
allergic rhinitis
IgE-mediated response associated with inhaled allergens that causes mast cell degranulation and histamine release eventually leading to cytokine influx and infiltration of eosinophils and WBCs resulting in mucosal edema and congestion
57
allergic rhinitis presentation
nasal itching, fatigue due to poor sleep, pale and edematous nasal mucosa, clear rhinorrhea, sneezing, and congestion
58
non-allergic rhinitis
mucosal edema which is usually triggered by strong smells, smoke exposures, temperature changes, or spicy foods causing rhinorrhea and congestion but otherwise feeling well
59
sinusitis
inflammation of the paranasal sinuses most commonly associated with viral URI resulting in edema, mucous production, and obstruction of sinus outflow tract creating pools of stagnant fluid which can eventually lead to bacterial sinusitis
60
main cause of orbital cellulitis
ethmoid sinusitis
61
acute sinusitis
sudden onset of symptoms which lasts < 4 weeks
62
subacute sinusitis
symptoms that last > 4 weeks but < 12 weeks
63
recurrent sinusitis
4 or more episodes (last at least 1 week) of sinusitis within 1 year
64
chronic sinusitis
symptoms lasting > 12 weeks
65
risk factors for sinusitis
anatomical abnormalities including a deviated septum, nasal polyps, trauma, decreased mucous transport due to CF or ciliary dyskinesia, immunodeficiency, body positioning, cocaine, barotrauma, smoking, oxygen use, or NG tube
66
bacterial sinusitis presentation
worsening symptoms for > 10 days and headache, fever, purulent nasal discharge with pain and pressure over the affected sinuses (maxillary usually)
67
complications of bacterial sinusitis
periorbital cellulitis and meningitis or cerebral abscess
68
aphthous ulcer (canker sore)
not completely understood but due to local cell-mediated immune response involving macrophage, lymphocyte, and neutrophil activation typically occurring during times of stress
69
candidiasis
fungal infection with candida albicans (gram-positive yeast with pseudohyphae) which thrives in warm, moist, and dark areas such as in the mouth or skin folds - if recurrent in adults, consider immunocompromised state like HIV or inhaled corticosteroids
70
thrush
candida albicans infection of the mouth in which overgrowth produces pseudomembrane that can be scraped off with a tongue depressor
71
thrush presentation
white pseudomembrane, erythema, discomfort, cotton feeling in the mouth, diminished taste, discomfort eating/swallowing, often associated with angular cheilitis bilaterally
72
pharyngitis
inflammation of the oropharynx mucous membranes causing edema and pain most commonly due to viral (rhinovirus, influenza, adenovirus) or bacterial infection (group A strep, chlamydia, H. influenzae, N. gonorrhea) but can also be associated with allergies, reflux, toxic exposure, and cancer
73
tonsillitis
inflammation of the tonsils due to viral or bacterial pathogens that cause cytokine release leading to increased vascular permeability, swelling, irritation of tonsillar tissue and nasal tissue (if viral), fever, and tonsillar exudate (if GAS)
74
complications of GAS tonsillitis
peritonsillar abscess, neck abscess, otitis media, sinusitis, pneumonia, scarlet fever, bacteremia, osteomyelitis, meningitis, arthritis, erythema nodosum, hepatitis, acute rheumatic fever, and toxic shock syndrome
75
laryngitis
inflammation of vocal cords due to viral (most common) or bacterial (M. catarrhalis, H. influenzae, S. pneumo) infection or yelling/singing/straining voice
76
acute laryngitis
symptoms lasting < 3 weeks
77
chronic laryngitis
symptoms lasting > 3 weeks and usually associated with irritants or laryngopharyngeal reflux
78
laryngitis presentation
PND, cough, sore throat, inflammation, edematous vocal cords, change in vibration of cords, change in voice quality/pitch (deeper)
79
fibrous tunic of the eye contains
cornea and sclera
80
vascular tunic (uvea) of the eye contains
iris, choroid, and ciliary body
81
sensory/neural tunic of the eye contains
retina containing photoreceptors
82
function of cornea
assists with focusing light and protecting the eye
83
cornea structure
clear, avascular, and outer layer contains nociceptors
84
normal intraocular pressure (IOP)
10 - 21
85
sclera structure
white aspect surrounding the eye made of dense connective tissue that connects to the cornea at the limbus and is more thin anteriorly
86
function of sclera
assists with protection and shape of the eye and is the point of attachment for eye muscles
87
lamina fusca
innermost layer of the sclera that absorbs light waves and prevents light from scattering
88
superior oblique eye muscle movement
down and medial
89
inferior oblique eye muscle movement
up and lateral
90
inferior rectus eye muscle movement
down and medial
91
superior rectus eye muscle movement
up and medial
92
lateral rectus eye muscle movement
lateral
93
medial rectus eye muscle movement
medial
94
oculomotor nerve or CN III eye muscles
superior, inferior, and medial rectus and inferior oblique
95
trochlear nerve or CN IV eye muscles
superior oblique
96
abducens nerve or CN VI eye muscles
lateral rectus
97
iris function
part of the vascular tunic of the eye which is responsible for eye color, creates the pupil, and separates the anterior and posterior chambers of the eye
98
iris innervation
oculomotor nerve or CN III
99
dilator pupillae function
mydriasis (pupil dilation) through sympathetic innervation
100
sphincter pupillae function
miosis (pupil constriction) through parasympathetic innervation
101
choroid function
part of the vascular tunic that wraps from the ciliary body around the posterior aspect of the eye which delivers nutrients to the photoreceptor neurons and assists with preventing reflection or scattering of light through light absorption
102
ciliary body function
part of the vascular tunic of the eye which attaches to the lens and changes its shape by pulling on suspensory ligaments (allowing for near and far accommodation) and secretes aqueous humor filling the anterior chamber
103
lens function
transparent structure made up of a capsule, epithelium, and fibers that refracts light and can be pulled to alter the shape and focus light for accommodation via the ciliary body
104
function of the aqueous humor
created in the ciliary body through plasma filtration (constantly secreted and reabsorbed) functioning to maintain intraocular pressure and bring nutrients to the avascular aspect of the anterior eye
105
function of the vitreous humor
thick, jelly-like fluid in the posterior aspect of the eye functioning to maintain intraocular pressure, hold the eye shape, and transmit light to the retina
106
canal of Schlemm
location at which aqueous humor drains from the anterior chamber of the eye and enters the venous system (episcleral vein)
107
the major artery supplying the eye
the internal carotid artery which branches into the ophthalmic, posterior ciliary, and central retinal arteries
108
bones comprising the orbital floor
maxillary, zygomatic, and palatine bones
109
bone comprising the orbital roof
frontal and sphenoid bones
110
lacrimal gland function
located above the eye laterally functioning to secrete fluid that moves across the cornea and drains into the upper and lower lacrimal punctum and lacrimal canaliculi
111
nasal lacrimal duct
where fluid from the lacrimal duct and sac drain into the nasal cavity
112
meibomian gland function
glands that run along the edge of the eyelid that secrete oil which prevents tears from evaporating too quickly and assists with lubricating the eye, there are about 20-30 in the lower eyelid and 40-50 in the upper eyelid
113
macula lutea
the area of the retina with the highest visual acuity with the central aspect being the fovea which contains only cones
114
retina components
photoreceptors consisting of rods and cones, bipolar cells, and ganglion cells (axons of ganglion cells form optic nerve)
115
cone photoreceptor function
contain photopsin, help to identify different colors of the visible light spectrum (red, green, and blue), and are responsible for visual acuity under well lit conditions (photopic vision)
116
rod photoreceptor function
contain rhodopsin, help to identify black/white/gray in poorly lit environments, and are responsible for night vision
117
pathway of light through the retina
a photon first strikes the photoreceptor causing a chemical change within the rhodopsin or photopsin, this causes a cellular change allowing for ion exchange and hyperpolarization of the cell, the cell then releases glutamate which stimulates bipolar cells which release more glutamate, this triggers an action potential which stimulates ganglion cells and the optic nerve
118
location of a lesion causing total loss of vision in one eye
complete lesion on the optic nerve - optic neuritis, ocular stroke
119
location of a lesion causing bitemporal hemianopia
lesion of the optic chiasm (chiasmal lesion) - pituitary tumor
120
location of a lesion causing nasal hemianopia
lesion of the outer edge of the optic chiasm
121
location of a lesion causing homonymous hemianopia
lesion of the optic tract prior to the lateral geniculate nucleus
122
location of a lesion causing homonymous hemianopia with macular sparing
lesion of the occipital cortex contralateral to side of vision loss causing the least amount of symptoms due to macular sparing
123
hemianopia
loss of one half of vertical visual field
124
anisocoria
asymmetric pupil size
125
relative afferent pupillary defect
defect in direct response due to nerve damage or severe retinal disease assessed with swinging flashlight test
126
Argyll Robertson pupil
seen with neurosyphilis where pupils will not constrict with light but will with accommodation
127
OD
right eye
128
OS
left eye
129
path of visual stimuli from the retina to the occipital cortex
the retina receives input from the opposite side of each eye and visual stimulation travels along the ipsilateral side of the optic nerve, when it reaches the optic chiasm the nasal hemiretina decussate but the temporal hemiretina continue on the ipsilateral side putting the same visual field on the same side for processing, once together they form the right and left visual tracts which pass through the lateral geniculate nuclei where some fibers terminate (reflexive eye movements), the remaining fibers go to the occipital lobe for visual processing
130
corneal abrasion presentation
damage to the cornea by mechanical or chemical mechanisms causing a foreign body sensation, photophobia, tearing, and significant eye pain
131
corneal healing process
corneal abrasions typically heal within 24-48 hours due to regeneration at the limbus and quick cell turnover
132
complications of corneal abrasion
increased risk for bacterial, viral, and fungal eye infections and inflammatory iritis
133
corneal ulcers
infection that goes through multiple layers of the cornea associated with trauma, contact lens wear, and dry eyes that is most commonly caused by S. pneumonia, Pseudomonas, and S, aureus infection
134
corneal ulcer presentation
severe pain, foreign body sensation, eye discharge, injection of the lid and conjunctiva, and blurry vision (possible visual acuity change depending on location of ulcer)
135
keratitis
surrounding inflammation of the cornea that is involved in the development and progression of corneal ulcers and can lead to loss of vision and corneal clouding
136
conjunctivitis
inflammation of the conjunctiva most commonly caused by viral infection and associated with adenovirus, measles, influenza, and mumps in which patient often has prior viral illness
137
conjunctivitis presentation
tearing, conjunctival injection, irritation (not much pain), clear discharge, may see follicles on slit lamp exam, it can start in one way and eventually affect the other eye as well
138
Hutchinson's sign
herpetic lesions or shingles along the division of the trigeminal nerve causing herpetic lesions on the nose and eventually leading to viral keratoconjunctivitis (due to herpes simplex or herpes zoster), this can cause corneal scarring and eventual loss of vision if not treated
139
bacterial conjunctivitis presentation
most commonly caused by S. aureus, S. pneumoniae, H. influenzae, and M. catarrhalis (Pseudomonas if contact lens used) and will present similar to viral conjunctivitis but with more mucopurulent discharge often causing lid adherence
140
hyperacute bacterial conjunctivitis
severe diffuse sight-threatening infection with rapid onset (< 12 hours) most commonly associated with N. gonorrhea causing severe eye pain, preauricular lymphadenopathy, and often presenting with urethritis
141
allergic conjunctivitis
IgE-mediated hypersensitivity leading to local mast cell degranulation and allergic reaction that is typically bilateral, can see associated chemosis, and can have other accompanying allergic symptoms such as sneezing, rhinorrhea, and congestion
142
pterygium
a proliferative disorder hallmarked by the abnormal growth of fibrovascular conjunctival tissue associated with large amounts of UV light exposure resulting in alteration of the limbus and increased angiogenesis which most commonly starts along the nasal aspect of the eye and reaches toward the cornea (can grow over months to years) causing inflammation
143
risk factors for pterygium
UV light exposure, abnormal tumor suppressor gene p53, HPV infection, and HLA expression
144
dacryocystitis
inflammation of the lacrimal sac most commonly due to Staphylococcus and Streptococcus infection after viral URI causing mucopurulent discharge and erythema along the inferomedial aspect of the eye which can lead to periorbital or orbital cellulitis if not treated
145
cataracts
degenerative changes of the crystalline proteins within the lens due to photo-oxidative damage and old cells being compressed centrally resulting in opacification of the lens and loss of transparency - can be age-related or non-age-related (due to trauma, uveitis, scleritis, radiation, and meds)
146
risk factors for cataracts
age, sunlight, smoking, ETOH, poor nutrition, metabolic syndrome, DM, HIV, high dose steroid use
147
entropion
internal folding of the lower eyelid that may be associated with age, tissue relaxation, or post-infectious (m/c Chlamydia trachomatis) and presents with foreign body sensation (due to lashes rubbing against eye), pain, and tearing
148
ectropion
eversion of the lower eyelid that may be associated with age or tissue relaxation which presents with tearing and dry eyes
149
chalazion
non-infectious occlusion or obstruction of a meibomian gland in the eyelid due to thick secretions which begins with inflammation and swelling and gives way to a non-tender nodule (usually absorbs over 2-8 weeks)
150
hordeolum
infection of a meibomian gland (internal) or a gland of Zeis or Moll (external) most commonly associated with Staphylococcus that can obstruct the eyelash follicle or their glands (Zeis or Moll) and creates a yellow pustule at the base of the lash with surrounding erythema and edema (usually resolves in 2-4 days), can lead to blepharitis if lash follicle is obstructed
151
orbital cellulitis
life-threatening and vision-threatening infection of the orbit including surrounding fat and ocular muscles similar to compartment syndrome most commonly due to S. aureus and strep infection that causes pain with eye movement, fever, normal visual acuity that may decrease with time, and possibly proptosis (does not involve the eye globe)
152
location at which bacterial rhinosinusitis can spread to the orbit
ethmoid sinuses via the lamina papyracea
153
optic neuritis
inflammation that causes demyelination of the optic nerve secondary to immune-mediated reactions involving systemic T cell activation which releases cytokines and B cell activation against myelin (formed by oligodendrocytes)
154
causes of optic neuritis
classically MS, can also be due to a viral infection, post-vaccination, inflammation of surrounding structures due to an infection, syphilis, tuberculosis, and sarcoidosis
155
afferent pupillary defect
when the light does not get through to the CNS preventing constriction of the pupils when light is pointed in the affected eye, associated with pathology of the optic nerve and optic neuritis (if not present, rules out optic neuritis)
156
glaucoma
increased intraocular pressure ( > 21 mmHg) due to obstruction of the canal of Schlemm preventing drainage of aqueous humor from the anterior chamber of the eye which causes optic neuropathy, decreased vascular flow to the retina, and visual loss
157
acute angle closure glaucoma
when the lens or peripheral iris blocks the meshwork or canal of Schlemm which results in increased pressure of fluid coming from the ciliary body bowing the iris and closing the outflow tract further, referred to as a pupillary block (more common in people with shallow anterior chambers)
158
acute angle closure glaucoma presentation
monocular eye pain, blurry vision loss, headache, conjunctival injection with cloudy cornea, and markedly increased intraocular pressure (maybe > 40 mmHg)
159
causes of papilledema
blurred optic disc margins caused by increased ICP due to malignant hypertension, pseudotumor cerebri, intracranial tumors, intracranial hemorrhage, hydrocephalus
160
macular degeneration
degenerative disease of the central aspect of the retina (macula lutea) characterized by macular drusen deposits (yellow deposits made of lipids and proteins) that typically starts out as atrophic or "dry" and becomes "wet" as it progresses, resulting in neovascularization, inflammation, and the formation of leaky vessels, causing painless monocular or binocular central vision loss or visual distortion
161
risk factors for macular degeneration
increased age, smoking, CVD, HTN, obesity, and sun exposure (may be genetically linked)
162
retinal detachment
photoreceptor degeneration caused by detachment of the neurosensory retina from the retinal pigment epithelium layer or choroid which typically occurs spontaneously but can also be associated with trauma, it is most commonly due to vitreous detachment leading to cobweb floaters visualized by patients and can progress over hours to weeks becoming vision-threatening (more likely to progress if tear is along superior aspect, is initially a larger tear, or if the patient moves head/eyes too much)
163
optic neuritis presentation
subacute, painful, central vision loss with ranging severity typically coming on over days, sometimes hours
164
retinal detachment presentation
acute, painless, progressive, peripheral unilateral vision loss typically with floaters initially and then "curtain coming down" peripherally
165
most common type of retinal detachment
rhegmatogenous caused by a hole/tear in the inner neuronal layer causing fluid accumulation between the retinal layers and in the tear pushing the surrounding retina outward and separating it from the pigmented epithelium
166
traction retinal detachment
caused by fibrosis/fibrovascular proliferation which leads to scar tissue buildup which pulls off the retina and usually more chronic in presentation
167
exudative/serous retinal detachment
caused by the accumulation of subretinal fluid from infection or inflammation (classically) or blood from a retinal vessel that pushes the retina away from its typical anatomic position
168
first branch off the internal carotid artery
ophthalmic artery
169
function of ophthalmic artery
branches into the central retinal artery (feeds the inner aspect of the retina) and posterior ciliary artery (feeds the macula)
170
central retinal artery occlusion presentation
sudden, painless, monocular vision loss where initial symptoms may include amaurosis fugax (sudden transient curtain drop-like vision loss) due to embolus from proximal atherosclerotic disease (associated with carotid disease)
171
central retinal artery occlusion fundoscopic exam findings
pale, translucent, and edematous retina where the macula will have intact choroidal circulation (supplied by posterior ciliary artery) and will stand out against the pale retina, referred to as a "cherry red spot"
172
color blindness
an x-linked recessive disorder causing an individual to have difficulty discriminating between different colors (typically red-green), especially in dim-lit environments due to low number or lack of certain pigments of cones (typically green) resulting in them seeing gray shades instead of color
173
the external ear canal is lined with
keratinized squamous epithelium
174
location of ceruminous glands
within the cartilaginous section of the external ear canal
175
function of cerumen
acidotic with antimicrobial effect, traps/deters insects, and is hydrophobic
176
location of the umbo
middle of the tympanic membrane
177
location of the incus
posterior and superior or to the umbo
178
location of the short process of malleus
superior to the umbo
179
location of the stapes
posterior to the umbo
180
the middle ear is lined with
respiratory mucosa
181
age when eustachian tubes become adult size
age 6 years
182
length of eustachian tubes
36-38 mm
183
eustachian tube muscle function
allow for dilation of eustachian tubes
184
effect of ascent on TM
ascent causes ear canal pressure to decrease which results in outward bulging of the TM (eustachian tube opens allowing pressure to equalize and TM moves back to normal position)
185
organ of Corti (cochlea) function
located within the cochlea where it converts sound waves into nerve impulses and transmits stimuli via the cochlear branch of the vestibulocochlear nerve
186
vestibule function
includes the semicircular canals, utricle, and saccule which give us position sense and transmit stimuli via the vestibular branch of the vestibulocochlear nerve
187
components of the inner ear
the semicircular canals, utricle, saccule, cochlea which contains the organ of Corti, and the vestibulocochlear nerve
188
components of the middle ear
the malleus, incus, stapes, oval window, and eustachian tube opening along with its associated muscles (tensor tympani muscle)
189
pathway of sound through the ear
sound from the outside world first strikes the TM causing vibration of the malleus, incus, and stapes which vibrates the oval window of the cochlea transmitting movement via cochlear endolymph which moves the tectorial membrane which causes hair cells with stereocilia to move on the organ of Corti converting movement into nerve impulses (through glutamate release) moving the signal up the spiral ganglion to synapse on the cochlear nerve
190
the utricle generates action potentials for
linear acceleration/head movements
191
the saccule generates action potentials for
vertical acceleration/head movements
192
location of utricle within inner ear
abutting the semicircular canals
193
location of saccule within inner ear
abutting the cochlea
194
vestibular system function
sensory hair cells called maculae within the utricle and saccule which are covered with gelatinous substance and otoliths create action potentials from mechanical movements (head movements) during which the otoliths and fluid move with gravity displacing the hair cells and triggering action potential to vestibular ganglion
195
semicircular canals contain
endolymph
196
crista ampullaris
a bulbous structure at the end of each semicircular canal which is the sensory aspect of the canals that contains hair cells and a cupula that generate action potentials when head movements occur (travel along vestibular ganglion)
197
test that can be used to differentiate between peripheral and central causes of vertigo
HINTS exam - include the Head impulse test, Nystagmus test, and Test of Skew
198
otitis externa
AKA swimmer's ear, inflammatory process of the external auditory canal caused by infection (most commonly Pseudomonas and Staphylococcus), allergic, or dermatologic pathology leading to itching, irritation, scratching, and further breakdown causing decreased cerumen production and a more alkalotic pH in the canal which leads to bacteria growth
199
otitis externa presentation
otalgia, pruritis, ear discharge, may have decreased hearing secondary to partial occlusion, and pain with external manipulation of the ear
200
otitis media
inflammation of the middle ear commonly due to prior upper respiratory mucosa inflammation causing a narrowed eustachian tube isthmus preventing the middle ear from draining and leading to increased fluid accumulation and organism overgrowth, most commonly caused by viral infections with RSV, rhinovirus, enterovirus, and coronavirus but can also be due to bacterial infection with S. pneumonia, H. influenza, and M. catarrhalis (H. influenza is m/c in bilateral AOM)
201
risk factors for otitis media
age 6 - 12 months due to eustachian tube anatomy, genetic disposition, exposure to pollutants such as tobacco smoking, bottle feeding due to increased colonization
202
most common cause of TM perforation/rupture
suppurative AOM
203
ruptured TM will typically heal spontaneously over 4 weeks if
defect is less than 25% of TM
204
mastoiditis
suppurative infection of mastoid air cells which is a complication of AOM where purulent fluid within the mastoid can cause an abscess destroying bone and the infection can spread to the cranial nerves, temporal bone, and the CNS
205
mastoiditis presentation
worsening AOM, pain over mastoid process posterior to the ear, fever/chills, otalgia, post-auricular erythema and tenderness
206
eustachian tube dysfunction
dysfunction typically occurs at the cartilaginous part of the eustachian tube, not the bony portion, secondary to functional issue or obstruction, causing an inability to regulate middle ear pressure (creating negative pressure in the ear) most commonly associated with edema but also can be poor muscular function
207
eustachian tube dysfunction presentation
otalgia, retracted TM, effusion, decreased pneumatic changes, hearing diminished
208
acoustic neuroma
a very slow growing benign tumor of the Schwann cells of the vestibulocochlear nerve that most commonly occurs at the porus acusticus (where cells transition from the CNS to PNS) at the superior and inferior branches
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acoustic neuroma presenting in pediatric population is concerning for
neurofibromatosis type 2 (NF2) which affects chromosome 22 and leads to defect in tumor suppressor gene within Schwann cells (acoustic neuromas are typically bilateral in this population)
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acoustic neuroma presentation
symptoms associated with mass effect and compression on cranial nerves, decreased hearing and tinnitus if cochlear nerve is involved, gait instability if vestibular nerve is involved, facial paresthesia and pain if trigeminal nerve is involved, change in taste and facial paralysis if facial nerve involved, ataxia if continues to grow and compresses cerebellum and brain stem
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benign paroxysmal positional vertigo (BPPV)
most commonly caused by calcium debris in the semicircular canal or canalithiasis most commonly affecting the posterior canal and causing false activation of hair cells similar to that of endolymph moving when there is a real stimulus resulting in a false sense of spinning with an idiopathic origin
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causes of BPPV
usually idiopathic but can also be due to Meniere's disease, trauma, vestibular neuronitis, and surgery
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BPPV presentation
dizziness or feeling that the "room is spinning" that lasts seconds to minutes brought on by turning or tilting the head, there may be nausea/vomiting but no change in hearing, otalgia, or tinnitus
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labyrinthitis
inflammation of the labyrinth including both branches of the vestibulocochlear nerve associated with viral infection or post-infectious inflammation (otitis media, meningitis, mastoiditis) causing peripheral vertigo, nausea/vomiting, and change in hearing (hearing loss) and tinnitus
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vestibular neuritis
inflammation of the vestibular branch of the vestibulocochlear nerve associated with viral or post-viral inflammation causing peripheral vertigo, nausea/vomiting, but does not affect hearing
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ototoxic drugs
salicylates (aspirin), NSAIDs, aminoglycosides (gentamicin, neomycin), erythromycin, vancomycin, quinidine, loop diuretics (furosemide), chemotherapeutic agents
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common causes of peripheral vertigo
BPPV, Meniere's, labyrinthitis, alcohol intoxication
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central causes of vertigo
brainstem/cerebellar tumor, stroke or hemorrhage
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tinnitus
perception of sounds that are not related to external stimuli
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most common cause of subjective hearing loss
damage to the cochlear hair cells
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conductive hearing loss
inability to conduct sound waves from the external ear to the inner ear due to disorder with the EXTERNAL or MIDDLE ear
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sensorineural hearing loss
hearing deficit due to pathology within the INNER ear
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presbycusis
age-related symmetrical hearing loss that reduces the ability to perceive higher-frequency sounds that may be associated with intrinsic changes such as change in mitochondrial functioning or HTN or extrinsic changes such as prolonged noise exposure, ototoxic meds, and diet
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causes of sensorineural hearing loss
infections such as viral cochleitis, herpes, influenza, measles, mumps, rubella, HIV, bacterial meningitis, Lyme, TB, syphilis, ototoxic meds, neoplasms, trauma, autoimmune disorders such as SLE, RA, Sjogren's, Kawasaki, temporal arteritis, vascular injuries such as CVA, TIA, cerebellar infarct, Meniere's disease, otosclerosis, MS, sarcoidosis, and hypothyroidism
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Meniere's disease
a disease characterized by increased endolymph pressure, referred to as endolymphatic hydrops, resulting in distortion and distention of the endolymph-containing portions of the labyrinthine system due to trauma, chronic OM, congenital hearing defect, otosclerosis, Paget disease, post-surgical complication, syphilis, or viral labyrinthitis
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Meniere's presentation
typically patients between the age of 20 - 40 years present with sudden episodic vertigo, unilateral tinnitus, and muffled hearing or hearing loss (may also have aural fullness outside of the above classic triad)
