Lecture 24 - Orbit I Flashcards
What is the ligament that forms the lateral portion of the oribit?
Postorbital ligament
What are the four regions of the orbit?
Roof, lateral wall, medial wall, and floor
What are the components of the orbit??
Zygomatic, lacrimial, frontal, maxilla, and palatine
What is the floor of the orbit made of?
Zygomatic, maxilla, and palatine
What are the supportive connective tissues of the eyelids?
Orbital septum and Tarsus
What is the orbital septum?
Connective tissue sheet
What is the tarsus?
A Fibrous structure
What are embedded into the tarsal plates?
Tarsal glands
What are tarsal glands?
Modified sebaceous glands that secrete only oily substance that increase the viscosity of tears and decrease tear evaporation
What is a chalazion?
Inflammation/blockage of the tarsal/meibomian gland
What is conjunctiva?
Non-keratinized, stratified squamous epithelium with goblet cells
What is within the conjunctival sac?
Bulbar and palpebral conjunctiva
What is the palpebral conjunctiva made of?
Superior and inferior fornices
What is conjuncitivitis?
Common, Primarily infectious conjunctivitis caused by different bacteria, viruses, mycoplasma, fungi, and parasites
What is the canthi?
Meeting sits of the upper and lower eyelids
What are the palpebral commissures?
CT of the corner of the eyes
What are the muscles involved in moving the eyelids?
Orbicularis oculi and levator palebrae superioris m.
What nerve innervates the orbicularis oculi?
CN VII
What nerve innervates the levator palebrae superioris m.?
CN III
What is the path of lacrimal gland?
Lacrimal gland - lacrimal punctum - lacrimal canaliculi - nasolacrimal duct
What is the major component of the tear film from goblet cells?
Glycoprotein
What part of the tears do the tarsal glands make?
oily component
What is the tenon’s capsule?
Membrane pierced by ciliary structures and muscle tendons, makes the episcleral space
What is within the episcleral space?
Lymph
What are the three “layers” of the eye?
Sclera - choroid - ora serrata
What is the choroid?
Layer containing blood vessel
What is within the anterior layer of the iris?
Containing constrictor pupillae
What nervous system that acts on the anterior layer of the iris?
PNS
What is within the ciliary body?
Containing the ciliary muscles
What nervous system that acts on the ciliary muscle?
PNS
What is the ora serrata?
Junction between the retina and ciliary body
What is contained within the posterior layer of the iris?
Dilator pupillae m.
What nervous system acts on the dilator pupillae m.?
Sympathetic
What is the nerve layers of the eye, starting most rostral?
nerve fiber - ganglion cell - inner plexiform - inner nuclear - outer plexiform - outer nuclear
What is the canal of schlemm?
Drains aqueous humor from anterior chamber to venous system
What is contained within the retrolental?
Vitreous body
What is contained within the prelental?
Anterior and posterior chambers, aqueous humor
What is the function of the suspensory ligaments of Zinn?
Tension on or relaxtion of change shape of the lens
What fibers are above the iris?
Zonular fibers
What is the state of the ciliary muscle without nervous stimulation?
Relaxed
What is the state of the zonular fibers without nervous stimulation?
Under tension
What is the state of the lens without nervous stimulation?
Stretched thin to refract light
What circumstance needs the lens to be stretched thin?
Distant vision
What is the state of the ciliary muscle with nervous stimulation?
Ciliary muscle contracts
What is the state of the zonular fibers with nervous stimulation?
Relax
What is the state of the lens with nervous stimulation?
Internal tension causes the lens to become more spherical to refract light
Why would you can your lens to be spherical?
Near vision
What nerve is active in the eye with bright light?
Ciliary ganglion
What CN works to constrict the pupil?
CN III
