Ear Flashcards

1
Q

Parts of ear

A

External
Middle
Dinner?

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2
Q

External ear components

A

Pinna
external auditory canal (acoustic meatus)

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3
Q

Middle ear components

A

Three Ossicles.
In order of decreasing size:

Malleus- tensor tempani muscle connection

Incus

Stapies- stapedius muscle connection

Stapes smallest bone of body

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4
Q

Inner ear components

A

Cochlea for hearing

Utricle and saccule for linear balance

Semicircular canals for angular balance

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5
Q

Which arch is external ear made up of?

A

Pinna- 1st pharyngeal arch
Rest- 2nd pharyngeal arch

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6
Q

External auditory canal made up of?

A

1st ectodermal cleft

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7
Q

Tympanic membrane made up of?

A

ALL 3 germ layers

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8
Q

1st ectodermal pouch makes?

A

Middle ear
Antrum
Eustachian tube

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9
Q

Ear ossicles made up of which pharyngeal arch?

A

Malleus + incus - ( + tensor tympani muscle) — 1st arch

Stapies + (stapedius muscle) 2nd arch

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10
Q

What is inner ear/cochlea made up of?

A

Neuroectoderm (Ottic placode)

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11
Q

When do pinna and cochlea completely develop?

A

20 weeks of intrauterine life

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12
Q

What are the congenital anomalies of external ears?

A

Incisura terminalis
Darwin’s tubercle
Bat ear
Microtia
Anotia

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13
Q

What is incisura terminalis?

A

It is a point at which the 1 and 2 pharyngeal arches merge.
If there is no fusion, a pre auricular sinus is formed.

There is no infection or complain.

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14
Q

What is Darwin’s tubercle?

A

It’s a conical elevation. Outer curve
Anomaly

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15
Q

What is bat ear deformity?

A

Inner curvature (anti helix) is absent

Plastic reconstruction at 6 to 7 years
Otoplasty

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16
Q

What is microtia and anotia?

A

Microtia- small pinna
Anotia- absence of pinna

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17
Q

What is the tip of malleus called?

A

Umbo

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18
Q

Oval window is attached to which bone?

A

Footplate of stapes

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19
Q

What are the four normal tympanic membrane landmarks?

A

1 lateral process of malleus
2 handle of malleus
3 light reflex (cone of light)
4 tip of umbo most important

20
Q

Tympanic membrane parts

A

Upper part= Pars flaccida -2 layers
Lower part= Pars Tensa- 3 layers (fibrous layer aswell)

21
Q

Pinna haematoma
Dx
Complications
Rx

A

Pt. Will present w Hx of trauma, boxer.

Pooling of blood between cartilage and pericardium due to trauma

Complications: post traumatic ear deformity— cauliflower/ boxers ear

Rx- incision and drainage/ aspiration. + pressure bandage.

22
Q

Nerve supply of pinna

A

Greater auricular nerve

23
Q

External auditory canal size

A

24 mm
Outer 1/3rd cartilage(8mm)
Inner 2/3rd bony

24
Q

Rudimentary openings in external ear

A

fissure if Santorini in cartilaginous part
foremen of Hushke in bony part

Natural defects
Infection may reach parotid gland via

25
Q

Nerve supply of roof and Ant. wall of EAC?

A

Auriculo-temporal branch of mandibular nerve

26
Q

Nerve sup. of floor and Post. part of EAC?

A

Auricular branch of vagus nerve
Arnold’s OR Alderman’s nerve

27
Q

Nerve sup. of postero-superior part of EAC?

A

Sensory branch of facial nerve
nerve of Winsberg

28
Q

Ear syringing

A

50/60 ml warm water in posterosuperior direction.

•If cold water used, pt. Will experience vertigo

•In Antero-inferior direction— irritation of Arnold’s nerve (vagus) will cause:
-Cough reflex
-Sudden vasodilation leading to vasovagal syncope.

29
Q

Localised external ear infection

A

Furuncle- infection of hair follicle
MCC- S. aureus

Rx- antibiotics + icthamamol glycerin packing (IG)

30
Q

Diffuse external ear infection

A

Diffuse otitis externa
MCC = pseudomonas

tropical Singapore swimmers.

Rx-
only Antibiotics.

31
Q

Elderly, diabetic, patient comes with complaints of severe earache, discharge and features of palsy. granulations in EAC.
Dx?

A

Malignant otitis externa

32
Q

Malignant otitis externa

A

-Severe life threatening infection.
Common in immunocompromised (HIV, covid)
-MCC- pseudomonas
-Can spread in skull base — skull base osteomyelitis causing CN palsies
( 9.10.11.12 CN)

33
Q

Most common CN involved in Malignant otitis externa

A

CN 7

34
Q

Malignant otitis externa Rx

A

Broad spectrum antibiotics
3rd gen cephalosporins
for 6-7 weeks
(Ceftriazone.)

35
Q

Wet newspaper appearance seen in which condition?

A

Otomycosis

36
Q

Otomycosis
Dx
Rx

A

Fungal infection of the external ear

MCC- aspergillus niger
(Black newspaper appearance)
2nd-
Candida
(Cloudy white)
Main complaint- itching

Rx- aural toilet. Plus antifungal eardrops

37
Q

Bullous Myringitis

A

Also called myringitis bullosa
Blebs or balloons over the tympanic membrane, a complication of infection.

38
Q

Whitish appearance of tympanic membrane?

A

-Calcification or fibrosis of Tympanic membrane called tympanosclerosis
-Can be seen after infection
-Chalky white appearance

39
Q

Tympanic membrane landmarks, not visible
Tympanic membrane sucked in

A

Retraction of tympanic membrane due to negative pressure generated inside the middle ear that creates a vacuum caused by blockage of eustachian tube.

Keratin deposition can also be seen in black colour

40
Q

Child, slapped by teacher, has mild conductive hearing loss. Brought to OPD
Dx?

A

Traumatic tympanic membrane perforation

41
Q

Traumatic Tympanic membrane, perforation
Rx?

A

Reassurance

Or Conservative
No infection so there will be no treatment as the tympanic membrane is self healing w/I 3-6 months
Self resolving condition

42
Q

Middle ear also called?

A

Tympanum

43
Q

Main function of middle-ear?

A

Impedance matching

44
Q

What is impedance matching?

A

In inner ear, we have fluid called endolymph and perilymph.
When The sound reaches inside the inner ear, It will be diminished because of a change in medium as there is more resistance in fluid medium.
to overcome that, we need to amplify the sound.
usually done by the decreasing size of the ear ossicles along with the difference in the surface area of the tympanic membrane and the surface area of the oval window, causing amplification of sound.

45
Q

Nerves along the petrous Apex?

A

5 and 6 CN

46
Q

Roof of middle-age

A

Tegmen Tympani

above that is Dura matter of brain
above that temporal lobe of the brain