Skull base

Question 1

Which semicircular canal is entered first in a translab approach

Answer 1

lateral semicircular canal, then
posterior, then
superior

Question 2

Three nuclei of vagus nerve

Answer 2

Nucleus ambiguus: main motor nucleus. Muscles of the pharynx/larynx. Parasympathetic inhibition of cardiac activity.

Dorsal nucleus of vagus: in the floor of fourth ventricle. Parasympathetic MOTOR innervation to thoracic and abdominal organs. Therefore can get bradycardia etc during fourth ventricular tumours

Nucleus tractus solitarius: Visceral afferents from 9, 10, 7. Therefore receive fibres from geniculate ganglion, and taste.

Question 3

Cabergoline in acromegaly

Answer 3

Can be added when somatostatin receptor ligand is ineffective.
Can normalise IGF-1 in 40-50% cases.

Approx 30% of prolactinomas also have raises GH. Can be controlled with same receptor

Question 4

What does testosterone supplements do to fertility

Answer 4

Reduces sperm count.

Start men on gonadotrophs when trying to conceive