Anatomy of the eye (1) Flashcards
Where do the axons from the optic tract synapse?
Lateral geniculate nucleus
What 5 bones of the skull make up the orbit?
- Frontal
- lacrimal
- zygomatic
- sphenoid
- palatine
What are the main differences between herbivorous and carnivorous orbits?
Carnivores (and pigs) have incomplete orbit; connected by orbital lig.
What structures pass through the orbital foramina?
Ophthalmic artery and vein and orbital vein. Also many CNs
What does the periorbital fascia contain?`
extra-ocular muscles, nerves, vessels
What extra-ocular muscle do birds and reptile lack?
Retractor bulbi`
Which muscles does III, occulomotor nerve innervate?
- D rectus
- V rectus
- M rectus
- V oblique
Which 2 muscles is the Abducens nerev innervate?
- L rectus
- Retractor bulbi
Name two/three layers of orbital fascia
- Peri-orbital fascia
2. Fascia Bulbi
What are meibomian glands?
- produce lipid layer
* open onto margin
Canthal ligaments are also called?
Palpebral lig
Which canthal ig is missing in dogs?
Lateral
What is Distchiae?
When hairs grow out of the Meibomian glands and damage cornea
What is the function of Orbicularis Oculi and what innervates it?
- closes eyelids
- Facial
Levator Palpebrae Superioris is innervated by..
Occulomotor
Both lat and med retractor anguli oculi are innervated by..
Facial
What nerve is responsible for the sensory aspect of the eyelids?
Trigem, ophthalmic and maxillary branches
What is the Lacrimal Caruncle and what animal?
Horses,
Exposed pigmented sclera
What are three components of tears and what glands produce them?
- Lipid; Meibomian glands on 3rd eyelid
- Mucin : Goblet cells on conjunctiva at Bulbal surface
- Aqueous: 3rd eyelid gland and lacrimal glands.
What epithelium is the anterior epithelium of the cornea?
Stratified squamous superficially, becoming Columnar epi
Describe the stroma of the eye
- Aligned collagen fibrils into lamellae
- keratinocytes
- ground substance
What is the Descemets membrane
underlying endothelial membrane in posterior cornea
What does the Descemets membrane do?
ensure dehydration of the cornea to remain clear
