TOPIC 2- 27. The lacrimal apparatus, the eyelids and the conjunctiva. The innervation of the lacrimal gland

Palpebral fissure

Opening betweent the two eyelids

Superior and inferior tarsal plate

?

Skin

What is the eyelid covered with on its anterior side?

Conjunctiva

What is the eyelid covered with on the posteror side

Lateral palpebral ligament

Star?

Medial palpebral ligament

Arrow?

- Levator palpebrae superioris
- Palpebral part of orbicularis oculi muscle

Which striated muscles does the eyelid contain?

Opening the eyelid

What is the function of levator palpebrae superioris?

Oculomotor nerve

What is the innervation of levator palpebrae superioris?

Closing the eye lid

What is the function of the palpebral part of the orbicularis oculi muscle?

Facial nerve

What is the innervation of the palpebral part of the orbicularis oculi muscle?

Vascularized, thin mucous membrane

What is the conjunctiva?

- Lacrimal gland
- Lacrimal lake
- Superior and inferior lacrimal canaliculi
- Lacrimal sac
- Nasolacrimal duct

What are the components of the lacrimal apparatus?

Lacrimal fossa

Where is the lacrimal gland located?

- Orbital part (2/3 of the gland)
- Palpebral part (1/3)

Which are the parts of the lacrimal gland?

Tendon of levator palpebrae superioris

What separates the lacrimal gland into orbital and palpebral part?

Compound tuboalveolar serous gland

What type of gland is the lacrimal gland?

An area of the conjunctiva on the medial angle of the eye which collects the tears

What is the lacrimal lake?

Collect the tears fron the lacrimal lake to the lacrimal sac

What is the function of superior and inferior lacrimal canaliculi?

Superior and inferior puncta

What is the lateral opening of the superior and inferior lacrimal canaliculi called?

Lacrimal part of the orbicularis oculi

What surrounds the lacrimal sac?

Creating a vacuum in the lacrimal sac, so that is draws the tears faster away from the eye

What is the function of the lacrimal part of orbicularis oculi?

Nasolacrimal canal

Where is the nasolacrimal duct located?

Drains the tears from the lacrimal sac into the nasal cavity

What is the function of the nasolacrimal duct?

Below inferior nasal concha

Where does the nasolacrimal duct open into?

- Somatosensory
- Parasympathetic and sympathetic visceromotor innervation
- Viscerosensory

What type of innervation does the lacrimal gland have?

- Lacrimal nerve (from opthalmic nerve)

How is the somatosensory innervation of the lacrimal gland?

From superior salivatory nucleus:

- facial nerve -> greater petrosal nerve, -> (through foramen lacerum) -> (through pterygoid canal) -> synapses in pterygopalatine ganglion -> postsynaptic fibers first in zygomatic nerve and then in lacrimal nerve, innervates lacrimal gland

How is the parasympathetic visceromotor innervation of the lacrimal gland?

Preganglionic parasympathetic fibers from the lateral horn of the grey matter in the spinal cord -> synapses in the superior cervical ganglion -> fibers join the greater petrosal nerve through pterygoid canal and innervates lacrimal gland

How is the sympathetic visceromotor innervation of the lacrimal gland?

- Lipid
- Serous
- Mucin

What is the composition of the tear?

The lacrimal gland

Where does the serous fluid come from?

The tarsal glands

Where does the lipid come from?

The goblet cells of the conjunctiva

Where does the mucin come from?