Extraconal Space

Paired exocrine glands located in the superolateral aspect of each orbit. Its primary function is to secrete the lacrimal fluid (aqueous layer of the tear film) which cleans, nourishes and lubricates the eyes.

Structure

• Orbital part – lies above the aponeurosis of the levator palpebrae superioris muscle
• Palpebral part – lies below the aponeurosis of the levator palpebrae superioris muscle.
• Ducts – empty secretions into lateral part of the superior conjunctival fornix

Relations

• Superiorly – zygomatic process of frontal bone
• Anteriorly – orbital septum
• Posteriorly – orbital fat
• Inferolateral – lateral rectus muscle.

Blood Supply

• Lacrimal artery – branch of ophthalmic artery

Venous Drainage

• Lacrimal vein – drains into superior ophthalmic vein (empties into the cavernous sinus)

Lymphatic Drainage

• Lymphatic drainage – superficial partoid lymph nodes (empties into the superior deep cervical nodes).

Innervation

• Sympathetic (inhibit fluid secretion)
  • fibres originate from the superior cervical ganglion and carried by the internal carotid plexus and deep petrosal nerve. Join with the parasympathetic fibres in the nerve of the pterygoid canal and follow same route to supply the gland.
• Parasympathetic (stimulates fluid secretion) – Preganglionic fibres carried in greater petrosal nerve and then nerve of pterygoid canal, before synapsing at the pterygopalatine ganglion.