Ear

Question 1

Where does the frontal sinus drain?

Answer 1

via frontonasal duct into the semilunar hiatus of the middle meatus

Question 2

Where does the ethmoid sinus drain

Answer 2

into the middle and superior meatus

Question 3

Where does the sphenoidal sinus drain?

Answer 3

into the sphenoethmoidal recess

Question 4

Where does the maxillary sinus drain?

Answer 4

it drains into the semilunar hiatus into the middle meatus

Question 5

CN 5 V₁

Answer 5

innervates lateral wall and anterior septum of the nose as well as parts of the sensation of the upper face

Question 6

Choanae

Answer 6

opening at the back of the nasopharynx

Question 7

muscle of the soft palate

Answer 7

tensor veli palatini

Question 8

Muscles of the Middle Ear

Answer 8

• stapedius muscle
• tensor tympani muscle

Question 9

Anatomy of the Tympanic Membrane

Answer 9

Question 10

Describe the pathway of hearing sensation

Answer 10

• oval window vibrates the perilymph fluid in the inner ear which is then transferred to the endolymph fluid within the Organ of Corti within the cochlea which stimulates hair cells
• hair cells transmit sound information to the CNS via CN VIII
• CNS: CN VIII → medulla oblongata→inferior colliculus of midbrain → superior olives → thalamus → auditory cortex

Question 11

Semicircular canals

Answer 11

• filled with endolymph
• respond to rotation of the head in 3 planes
• hair cells at the base of the semicircular canals are distorted when the head moves in the x, y, z planes

Question 12

Vestibule

Answer 12

• made up utricle and saccule
• hair cells within the vestibule are pressed down by gravity, or if gravity /accelearation changes → hair cells become distorted

Question 13

Vestibular pathway

Answer 13

• for balance and sensation of balance
• vestibular hair cells send signals via CN VIII (vestibulocochlear)
• received by pons and medulla oblongata → cerebellum and cerebral cortex

Question 14

Nystagmus

Answer 14

• rapid, involuntary eye movement as a result of activation of the vestibular system (usually side to side)

Question 15

CN V₃

Answer 15

mandibular brach: motor control of the tensor tympani muscle

Question 16

CN VII: Ear

Answer 16

somatic snesation of the external acoustic meatus, motor control of the stapedius muscle of the middle ear

Question 17

CN VIII

Answer 17

hearing, vestibular sensation

Question 18

CN IX: Ear

Answer 18

• somatic sensation of the external ear and middle ear

Question 19

Risk factors of otitis Media

Answer 19

smoking

family hx of OM

bottle feeding

attending daycare

Question 20

Bacteria associated with otitis externa and risk factors

Answer 20

• Bacterial:
  
  • Pseudomonas aerugonisa, Proteus vulgaris, staph aureus, or E. coli
• Fungal:
  
  • Aspergillus niger
  • Candida albicans
• Risk factors:
  
  • allergies
  • psoriasis
  • eczema
  • seborrheic dermatitis
  • decreased canal acidity (possibly due to repeated presence of water)
  • irritants (e.g. hair spray/dye)
  • **skin maceration that sets the stage for bacterial infection **

Question 21

Non-syndromic Hearing Loss

Answer 21

• partial or total hearing loss that not associated with other s/sxs
• classifications:
  
  • Autosomal Dominant (DFNA)
  • Autosomal Recessive (DFNB)
  • X-linked (DFNX)
  • each has subtypes number in the order they were discovered
• Mostly sensorineural but can less commonly be conductive
• Mixed inner and middle ear hearing loss. = DFNX2
  
  • called mixed hearing loss

Question 22

Primary Immunodeficiencies in ENT

Answer 22

• s/sxs: recurrent ENT infections
• whether its viral, bacterail, or fungal depends on which genes are involved
• early onset PIDs often have mendelian inheritance patterns
  
  • many are X-linked →occurring more commonly in boys

Question 23

Syndromic Hearing Loss

Answer 23

• hearing loss in addition to other medical issues
• characterized by mode of inheritance:
  
  • autosomal recessive (AR)
  • autosomal dominant (AD), or x-linked
• 3 major syndromes:
  
  • Usher syndrome: retinitis pigmentosa and senorineural hearing loss
  • Pendred syndrome: abnormal iodine metabolism in addition to hearing loss
  • Jervell and Lange-Nielsen syndrome: profound sensorineural hearing loss, cardiac arrhythmias caused by prolonged QT interval

Question 24

Waardenurg Syndrome

Answer 24

• ***Most common form of autosomal dominant sensorineural hearing loss***
  
  • 3% of childhood hearing loss
  • bilateral or unilateral sensorineural hearing loss, pigment abnormalities, and defining features of the face
    
    • white hair in front, differently colored irises (heterochromia irides), graying early, and vitiligo
    • face features: widely spaced medial canthi, broad nasal root, and unibrow (synophrys)
• tx: cochlear implant

Question 25

Vestibular Schwannoma and Neurofibromatosis 2

Answer 25

* benign tumors of the vestibularcochlear nerve (CNVIII) * NF2 = changes in the NF2 gene * regulations proteins production that functions as a tumor suppressor * usually caused by **spontaneous** mutation of the NF2 gene * otherwise inherited via autosomal dominant * S/Sxs: * problems with balance, tinnitys and **gradual** hearing loss * people with NF2 have less cafe-au-lait spots on the skin than those who have NF1 * Tx: surgical removal if possible * radiation therapy * VEGF inhibitor bevacizumab (VERY EXPENSIVE)

Question 26

Environmental Impacts on Hearing

Answer 26

* noise * aging * presbycusis * ototoxic drugs * aminoglycosides * can synergistically act with noise to cause severe hearing problems * viral and bacterial infections * Rubella (less so with vaccine and rhogam) * Cytomegalovirus is most common cause of congenital deafness\*\*\*\*\* * diet, stress, drugs, certain diseases and life styles

Question 27

3 Major Syndromes associated with Autosomal Recessive inheritance

Answer 27

* Usher Syndrome: * retinitis pigmentosa and sensorineural hearing loss * Pendred Syndrome: * abnormal iodine metablism with hearing loss * Jervell and Lange-Nielsen Syndrome: * profound hearing loss * cardiac arrhythmias caused by prolonged QT intervals

Question 28

Waardenburg Syndrome

Answer 28

* Autosomal dominant sensorineural hearing loss * white forelock, heterochromia, premature graying, vitiligo * unilateral sensorineural hearing loss * tx: cochlear implant

Question 29

Neurofibramatosis 2

Answer 29

* noncancerous tumors of the nerves vestibular cochlear nerves * bilateral acoustic neuromas/vestibular schwannomas * mutation of the *NF2* gene → tumor suppresor gene * less cafe au lait spots than in NF1 * Autosomal Dominant * gradual hearing loss, tinnitus, balance problems

Question 30

With the advent of vaccines what is the most common cause of congential deafness

Answer 30

* cytomegalovirus