Oral, orbital and nasal cavities

What separates the anterior and posterior tongue?

Sulcus terminalis

What is the general and taste innervation to the anterior 2/3 of the tongue?

General: Lingual nerve (branch of CN Vc)

Taste: chorda tympani (runs with CN VII, then lingual nerve)

What is the general and taste innervation to the posterior 1/3 of the tongue?

Both CN IX (glossopharyngeal nerve)

Lymphatic drainage of the anterior and posterior tongue

Anterior: Submental/submandibular nodes, then to deep nodes (unilateral)
Posterior: Directly to deep nodes (bilateral)

What is the function of the filiform papillae?

increase the friction between the food and the tongue, enabling the texture perception of food

What is the function of fungiform papillae?

Has tastebuds in between the papillae → taste

also sense temperature (thermoreception) and touch (mechanoreception)

Location of the major salivary glands

Parotid: encapsulated by the investing layer of deep fascia

Submandibular:

• deep part = superior to mylohyoid

• superficial part = inferior to mylohyoid

Sublingual: multiple ducts opening onto sublingual fold

Describe how the parasympathetic nervous system controls the eye

What does the parasympathetic nervous system controls in the head and neck?

• Constricts pupil

• Contracts ciliary muscle, allowing the lens to thicken for near vision (accommodation)

• Promotes secretion of the lacrimal glands.

• Promotes abundant watery secretions of salivary glands

Name the parasympathetic ganglia of the head and neck

• Ciliary ganglion

• Pterygopalatine ganglion

• Submandibular ganglion

• Otic ganglion

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Describe how the parasympathetic nervous system controls the glands in the head and neck

Describe how the parasympathetic nervous system controls the parotid glands

Why is the oral fissure an important landmark?

All glands above the oral fissure are innervated by the greater petrosal of CN VII

→ parotid + minor salivary glands (labial and buccal glands)

All glands below the oral fissure are innervated by the Chorda tympani of CN VII

→ submandibular, sublingual glands

What does the Sphenopalatine foramen connect?

the pterygopalatine fossa and the nasal cavity, transmitting the sphenopalatine artery and nerves

What area does epistaxis usually start?

Little’s area (Kiesselbach's plexus)

Management of a nose bleed

External compression (first aid): pinch soft part of nose for 20 mins

Cautery: silver nitrate/ electricity is used to burn to seal bleeding vessel

Internal compression (nasal packing)

Surgery (e.g., SPA/IMAX ligation)

Blood supply to the nose

Internal carotid artery → ophthalmic artery → anterior + posterior ethmoidal arteries

External carotid

→ facial artery → superior labial artery

→ maxillary artery → greater palatine + spheno-palatine arteries

Anastomose to form the keisselbach plexus

Innervation to the nose

nasopalatine nerve (branch of maxillary nerve)

nasociliary nerve (branch of the ophthalmic nerve)

Innervation to the external skin of the nose is supplied by the trigeminal nerve

What is Hutchinson’s sign and when is it seen and why?

The presence of a vesicular rash on the tip, side, or root of the nose indicating involvement of the nasociliary branch of the ophthalmic nerve (also supplies the cornea) → risk of corneal ulcers and loss of protective corneal sensation

usually seen in shingles/ Herpes Zoster Ophthalmicus (HZO)