Smell and taste

Question 1

Where are CN 5,6,7,8

Answer 1

pons

Question 2

Where are CN 9,10,11,12

Answer 2

medulla

Question 3

Pathway for olfaction

Answer 3

Odorant → g protein → ATP → cAMP → allows Na+ in

Question 4

Causes of anosmia

Answer 4

Smoking 
Rhinitis
Head injury 
Subarachnoid haemorrhage
Meningitis
Neural degeneration

Question 5

Idiopathic causes of anosmia

Answer 5

ahminoglycosides, tetracyclines, corticosteroids, methotrexate, opioids, L-dopa

Question 6

Effect of Parkinson’s on olfaction

Answer 6

reduced in early PD

Question 7

Unilateral headache and hypersensitivity

Answer 7

episodic migraine

Question 8

Hyperosmia

Answer 8

Increased sense of smell caused by lower threshold

Question 9

Hyperosmia causes

Answer 9

• Benzodiazepine withdrawal
• Inhalation of hydrocarbons - destroy dopaminergic receptors in olfactory bulb
• Methotrexate (treats psoriasis) causes hyperosmia

Question 10

Innervation of tongue

Answer 10

anterior 2/3 tongue is facial, posterior 1/3 is glossopharyngeal

Question 11

bells palsy and taste

Answer 11

Affects CN7 therefore loss of taste on half of tongue

Question 12

Ageusia

Answer 12

Complete loss of taste

Question 13

Dysguesia

Answer 13

Distortion/unpleasant taste

Question 14

causes of reduced taste

Answer 14

head trauma, malignancy, Bell’s palsy
Candida, URTI, HIV
Copper/lead, antibiotics, methotrexate
zinc def