Flashcards in Orbit Deck (66)
What bones make up the outer rim of the orbit?
Frontal, zygomatic, and maxilla bones
What bones make up the inner part of the orbit?
Sphenoid (greater & lesser wings), ethmoid, lacrimal, and palatine bones
What bones makeup the floor of the orbit?
Maxilla, zygomatic, palatine bones
What bones makeup the roof of the orbit?
Frontal, sphenoid bones
What bones makeup the medial wall of the orbit?
Ethmoid, lacrimal, frontal, maxillary, palatine bones
What bones makeup the lateral wall of the orbit?
Zygomatic, sphenoid, frontal, maxilla bones
What lies at the apex of the orbit?
What makes up the base of the orbit?
What is the axis of the orbit?
45 degrees from sagittal
What is the name for the space b/w the upper and lower eyelids?
Pelpebral fissure, bound by the upper and lower palpebral margins (palpebrae = eyelids)
The upper and lower palpabral margins meet at the ___________.
Canthus (medial and lateral canthi)
How many layers does a palpebra have associated w/it?
What is the major m. of the eyelid?
Levator palpabrae superioris m.
What is the lacrimal lake?
The larger medial angle of the eyelid
What is the fleshy elevation seen in the medial eye (next to the lake)?
What's contained in it?
- Lacrimal caruncle
- Sweat glands, sebaceous glands, cilia
What is the name of the CT band found just lateral to the lacrimal caruncle?
Plica semilunaris (separates sclera from lacrimal lake)
Where are lacrimal glands located?
What do the ducts of the lacrimal gland drain directly into?
- Superolateral aspect of eye
- Superior palpebral fornix (of upper lid. aided by blinking)
What is the function of the puncta lacrimali?
Where are they located?
- Drain opening for the tears
- Medial side of upper and lower lid
What is the function of the lacrimal canaliculus?
Where are they located?
- It's a duct from the puncta lacrimali to the lacrimal sac
- Upper and lower palpebrae
What is the lacrimal sac?
Where is it located?
- Collection of fluids
- Fossa of lacrimal bone
Where does the nasolacrimal duct drain?
What do the recti mm. originate?
Anulus tendineus (fibrous ring encircling inf and sup orbital fissures + optic canal)
- Placed medially, so mm. travel laterally and anteriorly to reach eye
Where does the superior oblique m. originate?
Where does the inferior oblique m. originate?
Where does the levator palpebrae superioris m. originate?
What are the vertical axis actions of each of the 6 eye mm.?
Medial rectus: none
Lateral rectus: none
Superior rectus: elevates
Inferior rectus: depresses
Superior oblique: depresses
Inferior oblique: elevates
What are the horizontal axis actions of each of the 6 eye mm.?
Medial rectus: adducts
Lateral rectus: abducts
Superior rectus: adducts
Inferior rectus: adducts
Superior oblique: abducts
Inferior oblique: abducts
What does the superior division of the oculomotor n. innervate?
Superior rectus and levator palpebrae superioris mm.
What does the inferior division of the oculomotor n. innervate?
Medial and inferior recti, inferior oblique mm.