Session 6 - Group work questions

Question 1

What is the sensory nerve supply to the aurcicle of the external ear and the tympanic membrane

Answer 1

The outer aspect of 
the auricle is 
supplied by: 
a) auriculotemporal 
nerve(Viii) 
b) greater auricular 
nerve (C2 & C3 of 
the 
cervical plexus).

Question 2

What is the sensory nerve supply to the tympanic membrane?

Answer 2

The External Surface
a)Auriculotemporal nerve, a branch of
the mandibular division of the fifth
nerve

b) Small branch of the Vagus (CN X)

Internal Surface
Supplied by the Glossopharyngeal nerve

Question 3

What is the most important posterior relation of the mastoid antrum and explain your answer

Answer 3

• The mastoid antrum is a 
cavity in the petrous portion 
of the temporal bone, 
communicating posteriorly 
with the mastoid cells and 
anteriorly with the 
epitympanic recess of the 
middle ear. Lying in front of 
this assembly is the sigmoid 
venous sinus (a dural sinus) 
and the cerebellum. 
Infection in the region of 
the mastoid may spread to 
involve these structures

Question 4

Name three branches from the facial nerve given off in the petrous temporal bone

Answer 4

Great petrosal nerve
Nerve to stapedius
Chorda tympani

Question 5

What is the fuctional significance of the great petrosal nerve?

Answer 5

Contains preganglionic parasympathetic fibres that are destined for the sphenopalatine ganglion. From here the postganglionic fibers are distributed to the lacrimal gland and glands to the nose

Question 6

What is the functional sig of the nerve to the stapedius

Answer 6

motor 
to the stapedius muscle which 
damps down movements of the 
stapes and prevents damage 
to the inner ear should it be 
subjected to loud noises.

Question 7

What is the funcitonal significance of the chorda tympani?

Answer 7

special taste fibres from the anterior
2/3rd of the tongue and preganglionic parasympathetic
secretomotor fibres to the submandibular ganglion(**) from where
they are distributed to the sublingual and submandibular salivary
glands.

Question 8

Why are you given a hard-boiled sweet to eat at take-off and landing during air travel?

Answer 8

Swallowing opens up the auditory tube 
that allows equalisation of pressure 
from the middle ear to the ‘outside 
world’. During take-off and landing, the 
pressure changes are quite noticeable 
and unless the tube is opened, the 
increased air pressure inside the middle 
ear may cause considerable pain.

Question 9

When clearing the ears with a cotton-wool bud
stick, why do some people start coughing and a
few people even vomit?

Answer 9

The nerve supply of the auditory canal 
and tympanic membrane is via the 
auricular branch of the vagus nerve. 
This nerve may also carry 
glossopharyngeal and facial nerve 
fibres and some people who are 
particularly sensitive to stimulation 
of these nerves may well develop 
an ear-cough reflex or occasional 
vomiting which may be associated with 
vagal and glossopharyngeal innervation. 
Sometimes a persistent lump of wax 
against the tympanic membrane may 
be the cause of unexplained cough.

Question 10

2 What are the implications of a haematoma to the

cartilage of the auricle?

Answer 10

The cartilage is avascular and relies on diffusion of gases and
nutrients from the perichondrium. As the perichondrium has been
prised away because of the haematoma, that part of the cartilage is
deprived of gases and nutrients. It will thus undergo necrosis.

Question 11

Boy playing rugby, punched over ear with prominent bulge in upper auricle due to heamatoma

Between what anatomical layers had this bleed occured?

Answer 11

The auricle consists of cartilage overlaid by perichondrium which has
blood vessels within it. The haematoma is likely to have developed
between these layers.

Question 12

How is auricular haematoma treated?

Answer 12

Drainage

Question 13

Without treatment, what complication will this patient develop overtime?

Answer 13

Necrosis of the underlying cartilage will lead to what is described as
a “cauliflower ear”.

Question 14

A 3-year old boy was taken to the GP’s 
surgery complaining of pain in the right 
ear. His mother informed the doctor 
that the boy had recently suffered an 
upper respiratory infection that 
appeared to be improving. On 
examination, the eardrum was found to 
be red, inflamed, bulging and with 
dilated blood vessels 
WHAT ARE THE DIFFERENTIALS

Answer 14

Referred pain and acute otitis media

Question 15

Why is otitis media more common in young children than adults?

Answer 15

Shorter, straighter Eustachian tube facilitates
easier spread of infection from the nasopharynx.
The immune system in the young is still maturing so
that they are mounting responses to new pathogens
all the time.

Question 16

A 5-year old boy presents at a clinic 
with a perforation of the eardrum and a 
large swelling in the mastoid region. 
Two days later, he was brought into the 
clinic looking very ill and drowsy. His 
mother informed that the child just had 
convulsions.

Explain what has happened to the infection in
this young child to cause the signs and symptoms
described and the likely complications that may cause
you concern.

Answer 16

Untreated otitis media spreads to mastoid air cells

From here, infection may break through walls (superior OR inferior) and infect different structures

Question 17

What occurs if mastoiditis infection breaks through superior wall?

Answer 17

Enters cranial cavity, affecting the meninges and temporal lobe of the brain, causing meningitis or abscess

Question 18

What occurs if mastoiditis infection breaks through inferior wall?

Answer 18

If the posterior wall if the mastoid 
antrum is invaded, the sigmoid dural 
venous sinus may become infected, 
causing a thrombosis with all its 
serious consequences. 
Meningitis, cerebral abscess or 
venous sinus thrombosis could all 
cause the symptoms and 
signs described