Session 11

Question 1

Origin of Rathke’s pouch? And for which pit? What is it?

Infundibulum? What is it?

Answer 1

Ectoderm/Ant, outpocketing of ectoderm of stomatodeum grows towards forebrain

Neuroectoderm/Post, downward growth of forebrain forming the neural tube.

Question 2

Describe development of the tongue?

Answer 2

Receives component from each of the arches. 2 lateral lingual swellings from arch 1.

3 median lingual swellings from arch 1 (Tuberculum Impar)

Cupola from arches 2,3,4

Epiglottal swelling from arch 4

Lateral swellings eventually overgrow TI, 3 arch component of Cupola overgrown the 2nd, extensive degeneration freeing tongue from floor. Leaving the lingual frenulum.

Question 3

Myogenic precursors that form muscles in tongue?

Innervation?

Answer 3

Occipital somites

XII

Question 4

Where is the primordium of the thyroid gland?

How does the thyroid descend to ant neck?

Injection between thyroid and tongue?

Complication?

Answer 4

Floor of pharynx between tuberculum impar and cupola

Starts at foramen caecum,bifurcated and descends as a bi-loved diverticulum connected by isthmus.

Thyroglossal duct

Thyroglossal cyst

Question 5

Describe blood supply to thyroid?

Most common cancers in head and neck?

Answer 5

Sup/inf thyroid artery

Sup/middle thyroid vein draining to IJV then left brachiocephalic vein.
inf thyroid vein straight into brachiocephalic vein

Squamous cell carcinomas

Question 6

Risk factors for H and N cancers?

4 types?

Staging?

Presentation?

Answer 6

Smoking,alcohol, dental hygiene, viruses (HPV), for thyroid irradiation exposure (radioactive iodine leak)

Larynx,pharynx,thyroid,oral/lip

TNM, note tumour is 1-4

Lump, pain,dysphagia,dysphonia (larynx)