Miscellaneous Flashcards
Which 2 bones form the superior wall of the orbit?
Frontal
Sphenoid
Which 3 bones form the inferior wall of the orbit?
Maxilla
Palatine
Zygomatic
Which 4 bones form the medial wall of the orbit?
- Ethmoid
- Maxilla
- Lacrimal
- Sphenoid
Which 2 bones form the lateral wall of the orbit?
Zygomatic
Sphenoid
What is this structure?
Optic canal
What is this structure?
Superior orbital fissure
Name the three canals
Which nerve innervates the orbicularis oculi?
Facial
Which two muscles elevate the eyelid?
- Levator palpebrae superioris
- Superior tarsal
What is the innervation of the levator palpebrae superioris?
Oculomotor nerve
What is the innervation of the superior tarsal muscle?
Sympathetic fibres from the superior cervical ganglion
What is the function of the tarsal (Meibomian) glands?
Secretion of an oily substance that increases the viscosity of tears and decreases the rate of evaporation of tears from the surface of the eyeball
A chalazion is a blockage of which structure?
Tarsal gland/Meibomian gland
A stye is a blockage of which structure?
Sebaceous or sweat glands associated with the eyelashes of the orbit
What is the primary lymphatic drainage of the orbit?
Parotid nodes
Which artery supplies the retina?
Central retinal artery (branch of the ophthalmic artery)
Which branches of the retinal artery supply the structures within the eyeball?
Long and short posterior ciliary arteries (branches of the ophthalmic artery)
What are the two layers of the retina?
- Neural (innermost - posteriorly and laterally)
- Pigmented (outer - continuous with the whole inner surface of the eye)
What is the ora serrata?
The junction between the ciliary body and the retina
Marks the transition from the optic part of the retina (photosensitive) and the nonvisual part (covers the internal surface of the ciliary body and iris)
What is the function of bipolar cells?
Transmission of signals from photoreceptors to ganglion cells
What is the function of retinal ganglion cells?
Transmit visual information to the brain in the form of action potentials
What is the function of horisontal and amacrine cells?
Form laterally direct neural circuits that modify the signals being transmitted along the pathway from photoreceptors to bipolar cells to ganglion cells
Which layer of the eyeball is continuous with the dura mater?
Sclera
Which layer of the eyeball is continuous with the pia and arachnoid mater?
Choroid
What are the layers of the cornea?
- Epithelium
- Bowman’s layer
- Stroma
- Descemet’s membrane
- Endothelium
How do each of the extraocular eye muscles move the eye?
How are the extraocular muscles clinically tested?
The ora serrata is the serrated junction between the retina and the ciliary body. This junction marks the transition from the simple, non-photosensitive area of the ciliary body to the complex, multi-layered, photosensitive region of the retina
What are 3 functions of the ciliary body?
- Production of aqueous humour
- Support for the iris and lens
- Accommodation and focusing (ciliary body)
- Drainage of aqueous at the angle of the anterior chamber
What are the five types of bones?
- Long
- Short
- Flat
- Irregular
- Sesamoid
What type of joint is the superior radioulnar joint?
Pivot
What type of joint is the humeroradial joint?
Ball and socket
