Orbital (Lect) Flashcards
What 7 bones contribute to the walls of the orbit?
- Maxilla
- Zygomatic
- Frontal
- Ethmoid
- Lacrimal
- Sphenoid
- Palatine
Bones in Roof of the orbit
- Frontal (most)
2. Lesser wing of Sphenoid
Bones of Lateral Wall of Orbit
- Zygomatic Bone
2. Greater Wing of Sphenoid
Bones of Medial Wall of Orbit
- Frontal
- Lacrimal
- Ethmoid
- Sphenoid
- Palatine
Bones of Floor of the the Orbit
- Maxilla - orbital surface
2. Palatine Bone
Spaces outside of orbit:
- Superior
- Inferior
- Medial
- Lateral
Superior:
- Anterior Cranial Fossa
Inferior:
- Maxillary Sinus
Medial:
- Ethmoid Air Cells
Lateral:
- Temporal Fossa
What do the 4 extrinsic mm. of the eye insert into?
Common Tendinous Ring
What is located in the superior group of orbit neurovasculature?
- Lacrimal and Frontal Branches of Opthalmic n. (V1)
- CN IV
- Superior Opthalmic V.
What is located in the middle group of orbit neurovasculature?
- CN II
- Opthalmic A.
- Superior Branch of CN III
- Inferior Branch of CN III
- Nasociliary Branch of Opthalmic n. (V1)
- CN VI
What is located in the inferior group of orbit neurovasculature?
- Inferior Opthalmic v.
What nerve gives parasympathetic innervation to the eye?
CN III
Where do PREganglionics destined for the eye synapse with POSTganglionic cell bodies?
Cilliary Ganglion
Where is the ciliary ganglion found?
In the orbit
How to POSTganglionics get to the structures that they innervate?
Hitchhike on SHORT CILIARY NN. (of V1)
What smooth muscles are controlled by parasympathetic innervation in the eye?
- Constrictor Pupillae
2. Ciliary muscles
What are the signs of Sympathetic Loss in the ocular region?
- Anhydrosis (lack of sweating)
- Miosis (contricted pupil)
- Ptosis (droopy eyelid)
- Enopthalmos (posterior displacement of eyeball in orbit)
What are the signs of parasympathetic loss in the occular region?
- Loss of Accommodation (can’t focus the eye, CN III)
- Mydriasis (dilated pupil, CN III)
- Loss of Lacrimation (lack of tearing, CN VII)
What is the periostium lining of the orbit called?
- continuous with?
Periorbita - continuous with periostium of:
- Infratemporal Fossa
- Middle Cranial Fossa
Describe the shape of the rectus muscles?
- Superior, Inferior, Lateral, and Medial Rectus muscles form a cone of muscle with the base forming on the sclera and the posterior apex forming at the tendinous ring
What makes up the majority of the tissue found within and around the musclular cone?
- purpose?
- Adipose Tissue
- Prevents the Rectus mm. and other extrinsic mm. from pulling the eyeball posteriorly
What is the suspensory ligament of the eye?
- what does it do?
- Suspends the Globe in the orbit to oppose gravity
**Kind of cradles the bottom of the eye
What connective tissue backbone is found in the upper and lower eyelids?
- Superior and Inferior Tarsal plates
Secretions of what gland lubricates the conjunctival sac?
- Lacrimal Gland
What muscle attaches to the posterior aspect of the superior tarsal plate?
- Levator Palpebrae Superioris
What muscle is embedded in levator palpebrae superioris?
- Function
- Significance
Superior Tarsal mm.
- Maintains and Open Palpebral Fissure
- one of 3 named smooth muscles in orbit outside of the globe (avascular)
What type of innervation controls the inferior and superior tarsal mm.?
- SYMPATHETIC
What 6 muscles are responsible for moving the globe?
Rectus mm.
- Superior Rectus
- Medial Rectus
- Inferior Rectus
- Lateral Rectus
Oblique mm.
- Inferior Oblique
- Superior Oblique
What muscle raises the upper eyelid?
- Levator Palebrae Superioris
What does the Frontal n. (V1) end as?
- Supratrochlear n.
What branch of V1 travels laterally after exiting the supraorbital fissure superior to the tendinous ring?
- Lacrimal n.
What nerve branches into the anterior and posterior ethmoidal nn.?
- where?
- Nasociliary n.
- Branches IN the orbit then branches penetrate the ethmoid
What artery runs with the nasociliary n.?
Opthalmic a.