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72 Cards in this Set
- Front
- Back
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What bones in roof of orbit?
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frontal
lesser wing of sphenoid |
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what bones in floor of orbit
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maxillary
zygomatic palatine |
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what bones in medial wall
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ethmoid
maxillary lacrimal sphenoid |
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what bones in lateral wall
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greater wing of sphenoid
zygomatic |
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what openings around orbit, what goes through them
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optic foramen - optic nerve, opthalmic artery
SOF - LFTSNIA + superior ophthalmic vein IOF - inferior ophthalmic vein infraorbital groove - nasociliary nerve supraorbital notch nasolacrimal canal |
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what is the contents of the orbit?
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globe
orbital fat lacrimal gland EOMs nerves blood vessels |
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what is the function of the orbit?
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support and protect the eye
separate the eye from external world and brain |
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blood supply
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ophthalmic artery and choriocapillaries
superior and inferior ophthalmic veins |
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eyelid structure (5 layers)
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- skin
- subcutaneous - striated muscle - fibrous tissue (tarsal) - mucous membrane (conj) |
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which muscles aid in opening the eye
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levator
muller inferior tarsal muscle fascia from IR muscle |
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where does lid get blood supply
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ophthalmic artery and lacrimal artery
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which nerves are involved in lid f(x)
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- ophthalmic and maxillary divisions of V
- CN VII (orbicularis oculi) - CN III (levator) also sympathetic to Muller muscle |
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3 layers of tears
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- oily (meibomein)
- aqueous - mucous (conj) |
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f(x) of tears
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irrigate and protect globe surface
washes away foreign bodies anti bacteria nourish cornea allows smooth refractive surface reflex and basal tears |
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blood supply for tear production
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lacrimal artery
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what is conjunctiva
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thin mucous membrane covering posterior surface of lids and anterior surface of globe, continuous with skin at lids and continuous with corneal epithelium at limbus
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what are sections of conj
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- palpebral
- bulbar - semilunar - caruncle - fornix |
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layers of conj
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epithelium
stroma |
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f(x) of conj
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secret mucousal tear film
nourish and protect anterior structures elimination of wastes |
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nerve supply of conj
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ophthalmic division of V
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how does cornea receive oxygen
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tear film
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what is refractive power of cornea
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40 D
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layers of cornea
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epithelium
bowman layer stroma descement membrane endothelium |
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what is blood supply of ciliary body
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anterior and posterior ciliary arteries
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nerve supply of ciliary body
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sensory - ophthalmic of V
motor - inferior of III (parasympathetic) and nasociliary branch of V (sympathetic) |
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what is retina
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thin, transparent membrane which lines inner 2/3 of globe
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what are the anterior and posterior limits of retina?
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- ora serrata
- optic disc |
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what are the layers of the retina?
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- RPE
- OS PR - IS PR - OLM - ONL - OPL - INL - IPL - GCL - NFL - ILM |
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where are rods and cones most concentrated
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rods periphery 15 degrees from macula
cones at macula no rods at fovea |
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how many rods, cones and optic nerve fibers in retina
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rods: 130(10^6)
cones: 6(10^6) ONF: 1.3(10^6) |
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what types of glial cells and their f(x)
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astrocytes - form BBB, BRB, BPB
oligodendrocytes - make myelin microglia - maintain ionic environment, macrophage f(x) |
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what are support structures of ONF
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meninges
- dura mater - pia mater - arachnoid mater |
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optic nerve blood supply
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central retinal artery
ophthalmic artery short posterior arteries |
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are EOMs smooth or striated
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striated
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what are myofibrils composed of? what type of muscles are they in
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actin (thin) and myosin (thick), present in striated muscle (give muscle striated appearance)
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what are the anatomic differences between EOM and somatic striated muscle?
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EOM contains smaller, finer muscle fibers
EOM more richly innervated (3:1) EOM HAVE 2 TYPE OF NERVe endings EOM have 2 types of muscle fibers |
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what are physiologic differences between EOM and somatic striated muscle
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- EOM fastest contracting muscles in body
- fatigue resistent - no expansion in size with use |
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how long is each rectus muscle
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40 mm
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which rectus muscle has longest tendon? shortest?
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longest - LR
shorterst - MR |
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what is the insertion of recti muscles
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spiral of tillaux
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blood supply of recti muscles
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ciliary arteries
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how long is the SO muscle
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60 mm
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how long is SO tendon? IO?
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30 mm
<1mm |
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what is Tenons capsule
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fibrous arc surrounds globe
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what are the three meninges
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dura mater
pia mater arachnoid mater |
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where is diencephalon located
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between midbrain (mesencephalon) and cerebral hemispheres
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where is the hypothalamus in relation of optic chiasm
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dorsal
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which CN nuclei in midbrain
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III, IV
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where is the red nucleus locates
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midbrain
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where is the sylvian aqueduct located
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midbrain
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what are the vertical gaze centers aND where are they located
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posterior commisure and riMLF
located in midbrain |
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where is V CN nucleus
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pons
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where is VI CN nucleus
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pons
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where is III CN nucleus
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midbrAIN
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where is VII CN nucleus
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pons
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where does the MLF pass through
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midbrAIN, PONS, and medulla
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what is the pathway of the optic nerve
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retina
optic nerve optic chiasm optic tract LGN radiations visual cortex (occipital lobe) |
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what is the pathway of the III CN?
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nucleus located in tegmentum of midbrain
muscle fibers come together to form the III CN, pass through cerebral aqueduct and red nucleus, emerge on anterior aspect of midbrain and pass through the superior cerebellar and posterior cerebral arteries, runs slightly inferior to pCommA, enters roof of cavernous sinus, and enters orbit through SOF through the annulus of zinn |
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what are all the subnuclei of cn III
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subnuclei for each muscle
- MR, IR, IO, SR(c) - Edinger-Westphal nucleus - Central caudal nucleus |
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what does the parasympathetic component of the III supply
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ciliary ganglion
ciliary muscle iris sphincter |
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what is the pathway of CN IV
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nucleus located in tegmentum of midbrain (at level of inferior colliculus), exits the brainstem dorsally, decussates and passes the posterior cerebral and superior cerebellar arteries, passes the dura, passes around brainstem at level of tentorial notch, enters the cavernous sinus slightly inferior to the III nerve, enters orbit through SOF above the annulus of zinn to innervate the SO muslce
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what is the pathway of CN VI
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nucleus located in pons, exits the pons passes PPRF and passes between pons and clivous bone, over the posterior portion of temporal bone and petrous ridge, enters cavernous sinus (body of CS) and enters porbit thru SOF through annulus of zinn
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what are the branches of CN VII
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greater petrosal nerve
zygomatic branch (frontalis and upper eyelids) |
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what are types of cells in retina
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photoreceptor cells - rods - rhodopsin pigment, cones - erythrolabe, chlorolabe, cyaolabe
BP CELLS hoprizontal cells ganglion cells (axons of ON) |
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Where is the circle of Willis
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surrounds optic chiasm
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does a chiasmal defect respect horizontal or vertical meridian
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vertical
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homonymous hemianopia
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post chiasm
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bitemporal hemianopia
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chiasmal
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vonWillbrand's knee
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junctional scotoma - central in one eye and arcuate in the other
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congruity of scotoma increases posteriorly or anteriorly
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posteriorlty
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LGN lesion = what type of VF defect
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"key" but very rare
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what is meyers loop?
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refers to fibers from the inferior retina - enter temporal lobe by looping around the lateral ventricles to synapse at the inferior calacrine fissure
(superior and macular go straight to cortex) |
