Phys Exam 3 Flashcards
Palpebral fissure?
Elliptical open space between eyelids.
Lower lid margin, at limbus, borders between cornea and sclera.
◦Canthus: corner of eye, angle where lids meet
◦Inner canthus: caruncle is small fleshy mass containing sebaceous glands
Tarsal plates
contain meibomian glands, which are modified sebaceous glands that secrete an oily lubricating material onto lids
Conjunctiva
Transparent protective covering of the eye
Cornea
covers and protects the iris and pupil
Lacrimal apparatus
What are the numbered parts of the eye?
- Upper eyelid
- Palpebral fissure
- Lateral canthus
- Lower eyelid
- Pupil
- Iris
- Sclera
- Medial Canthus
- Caruncle
- Limbus (between cornea and sclera)
How many muscles attach the eye to the orbit and direct to point of interest?
Six
What is conjugate movement?
Eached coordinated muscle (AKA yoked) move with one another ensuring the two eyes move. When they move the axes always remain parallel.
What are the four straight muscles?
Superior, inferior, lateral, and medial rectus
What are the two slanting muscles?
Superior. and inferior.
What is cranial nerve VI?
Abducens nerve, innervates lateral rectus muscles, which abducts eye.
What is cranial nerve IV?
Trochlear nerve, innervates superior oblique muscle
Label
- Bony orbit
- orbicularis oculi m.
- palpebral conjuctiva
- Bulbar conjunctiva
- posterior chamber
- anterior chamber
- cornea
- Tarsal plate
- meibomian glands
- sclera
What is cranial nerve III?
It is the oculomotor nerve that innervates all the rest of the muscles.
Label each muscle and the cranial nerve that controls it.
- inferior oblique, CN III
- superior rectus, CN III
- lateral rectus, CN VI
- inferior rectus, CN III
- superior oblique, CN IV
- medial rectus, CN III
- inferior oblique, CN III
- superior rectus, CN III
- lateral rectus, CN VI
- inferior rectus, CN III
- superior oblique, CN IV
Label
- superior rectus
- optic nerve
- lateral rectus
- inferior oblique
- inferior rectus
- medial rectus
- superior oblique (passing through trochlea)
Label
- Vitreous body
- Retina
- Choroid
- Sclera
- Macula
- Optic disc
- Retinal vessels
- Inferior rectus muscle
- Cillary body
- Posterior chamber
- Anterior chamber
- Lens
- Iris adn pupil
- Cornea
- Superior rectus muscles
What is the sclera?
A tough, white, protective covering.
What is the cornea?
part of the refracting media of the eye, it bends incoming light rays so they will be focused on inner retina.
What nerve stimulates blinking?
CN VII
What is the corneal reflex?
When the eye comes into contact with a wisp or cotton, stimulating a blink in both eyes.
What is the choroid?
Has dark pigment to prevent light from reflecting internally and is heavily vascularized to deliver blood to retina.
What is the iris and its function?
It functions as a diaphragm, varying in bright light to accomodate for near vision. It’s function is the muscles fibers of the iris contract in bright light to accommodate for near vision. The when light is dim, they will dilate for far vision.
What is the pupil?
It is round and regular. Size is determined by balance between PSNS and sympathetic chains of autonomic nervous system.
What is the lens?
Biconvex disc located just posterior to the pupil. It is transparent and serves as a refracting medium, keeping a viewed object in continued focus on the retina
How do you determine intraocular pressure?
Determined by balance between amount of aqueous produced and resistance to outflow.
What is the retina?
The visual receptive layer of the eye where light waves change into nerve impulses.
What retinal structures can be seen through an ophthalmoscope?
Optic disc, retinal vessels, general background, and macula.
What is the optic nerve?
AKA optic papilla, fibers from the retina coverage to form the optic nerve. Located on the nasal side of the retina. Color varies from creamy yellow orange to pink, it’s round/oval in shape.
What is the retinal vessel?
Normally included a paired artery and vein extending to each quadrant.
What is the macula?
Located on temporal side fundus. Slightly darker pigmented region surrounding fovea centralis, area of sharpest and keenest vision.
What is the pupillary light reflex?
Normal constriction of pupil when a bright light shines on the retina. It is a subcortical reflex that we cannot control. Sensory afferent link is CN II and motor afferent path is CN III.
What is the fixation?
Is a reflex direction of the eye toward an object attacting our attention. The image is fixed in the center of the visual field, the fovea centralis. This can be affected by drugs, alcohol, fatigue, and inattention (so… me… LOL)
What is accommodation?
Adaption of the eye for near vision. Occurs by increasing the curvature of the lens through muscle of the cilary body. Can observe pupillary constriction.
True or False, the infant does not have a macula at birth?
True. The infant’s macula will not mature until about 8 months.
At what age do infants establish binocularity?
3 to 4 months. They then can fixate on a single image with both eyes simultaneously.