Shared Flashcard Set

Details

Special Senses
Visual Accessoy Organs
76
Anatomy
Undergraduate 3
10/12/2011

Additional Anatomy Flashcards

 


 

Cards

Term
What do the eyelids do?
Definition
keep eyes moist

prevent scratches fom external forces
Term
What do eyelashes do?
Definition
keep debris out of eyes
Term
In comparison to regular hair, eyelashes are
Definition
more sensitive than other hair
Term
Name the glands in between the eyelashes.
Definition
tarsal gland

ciliary gland
Term
What is the purpose of the tarsal gland and ciliary gland?
Definition
produce lubricants to keep eyelids from sticking together
Term
What is a sty?
Definition
blockage of a tarsal or ciliary gland
Term
What is the conjunctiva?
Definition
membrane that lines the eyelids and anterior surface of the eyeball, except for the cornea
Term
What part of the eyeball does the conjunctiva not cover?
Definition
cornea
Term
What is the purpose of the conjunctiva?
Definition
protection and lubrication
Term
What is conjunctivitis?
Definition
pink eye, caused by infection, very contagious, causes inflamation of the eye
Term
What is the lacrimal apparatus?
Definition
part of eye that is made of glands and tear ducts.
Term
Where are tears made and secreted?
Definition
In the ducts of the larcrimal in the upper lateral part of the eye. They run across the eye towards the nose.
Term
The tears run into the nose?
Definition
through the nasolacrimal duct
Term
Name the 6 extrensic eye muscles.
Definition
superior rectus
inferior rectus
medial rectus
lateral rectus
inferior oblique
superior oblique
Term
What two muscles move the eye lids?
Definition
orbicularis oculi and levator palpebrae superioris
Term
What are the two basic eye movements?
Definition
saccades

slow scanning
Term
_____ ______ are among the most precisely and rapidly controlled skeletal muscles in the body.
Definition
eye muscles
Term
Where is aqueous humor stored?
Definition
between the cornea and lens
Term
What is vitreous humor?
Definition
a clear, gel-like material stored behind the lens
Term
What are the three tunics of the eye?
Definition
Outer, fibrous, cornea & sclera

Middle, vascular, choroid

Inner, sensory, retina
Term
Which part of the tunic is avascular?
Definition
fibrous tunic
Term
Sclera: what is it, where is it, what is its function?
Definition
White part of eye

Fibrous Tunic

eye muscles anchor to it
Term
Cornea: what is it, where is it, what is its function?
Definition
clear part of the eye that bends light so helps focus

it is in the fibrous tunic
Term
The cornea is largely made out of ________, but it is lined on both surfaces with ________ tissue
Definition
collagen
epithelial tissue
Term
Why do the epithelial layers of the cornea have sodium pumps?
Definition
they pump sodium ions across cornea, water follows it by osmosis. the water keeps the cornea compact-no over hydrating, swelling or loosing transparency
Term
From where does the cornea get nutrients and oxygen?
Definition
aqueous humor
Term
What are the components of the middle vascular tunic?
Definition
choroid, ciliary body and Iris
Term
What is the choroid?
Definition
highly vascular part of the vascular tunic, it is brown, deeply pigmented it absorbs stray light.
Term
What is the ciliary body?
Definition
a thickened extension of the choroid, forms a muscular ring around the lens. Supports the iris and lens and secretes aqueous humor.
Maintains the shape of the lens.
Term
What shapes of muscle fibers are in the Iris?
Definition
Circular fibers
radial fibers
Term
What happens when the circular fibers of the iris contract?
Definition
pupil becomes smaller
Term
What happens when the radial fibers of the iris contract?
Definition
Pupil enlarges
Term
What is the pupil?
Definition
The opening in the iris.
Term
What are the problems associated with complete albanism and eyes.
Definition
No pigment in eyes, look pink, have low vision, hard to get light to focus on eye and have bad depth perception
Term
What are the components of the sensory tunic?
Definition
Retina and optic nerve
Term
how is the retina held to the back of the eye?
Definition
by vitreous humor
Term
What is the fovea centralis?
Definition
a tiny pit in the middle of the macula lutea that produces the most finely detailed images
Term
What is the macula lutae?
Definition
a patch of cells directly posterior to the center of the lens on the visual patch of the eye
Term
What is the optic disc?
Definition
Where the optic nerve leaves the rear (fundus) of the eye.
Term
What is the blind spot of the eye?
Definition
the optic disc where there are no rods and cones
Term
What is retinal detachment and how does it happen?
Definition
Retinal detachment is a disorder of the eye in which the retina peels away from its underlying layer of support tissue. Initial detachment may be localized, but without rapid treatment the entire retina may detach, leading to vision loss and blindness.
Traumatic injury and the natural reduction of vitreous humor associated with aging
Term
What are photoreceptor cells?
Definition
cells that absorb light and generate a chemical or electrical signal, rods and cones
Term
Which photoreceptor is black and white sensitive, most useful at night?
Definition
Rod
Term
How many rods are in the retina and where are they?
Definition
100 million, all over the eye
Term
How many cones are in the eye and where are they located?
Definition
3 million, mostly in the macula lutea
Term
________ are the photoreceptors most useful during the day.
Definition
Cones, they need bright light to work
Term
What are the photoreceptors that interpret color?
Definition
Cones
Term
What are the three types of cones.
Definition
red, green and blue types
Term
Color blindness is X linked so it is more common in _____.
Definition
males
Term
Why you can see is because you break down _______ in rods and cones.
Definition
pigment
Term
Why you can see is because you break down _______ in rods and cones.
Definition
pigment
Term
What is neural convergence in the retina?
Definition
it occurs where multiple rods or cones synapse with on bipolar cell and again where the multiple bipolar cells feed into one ganglion cell
Term
What are the steps in light activation?
Definition

light->ganglion layer->bipolar cell layer->photoreceptors

 

the photoreceptor layer, bipolar layer, and horizontal layer, then the optic nerve.  This is also the order that they "fire"  Hope that makes sense!

Term
Name the photoreceptor pigments.
Definition
Rhodopsin
Iodopsin
Term
What is rhodopsin?
Definition
visual pigment of the rods.
Term
list the steps for signals being sent to the brain through rods
Definition
light->rhodopsin=>retinal and opsin
opsin->other moleules->neurotransmitter release->signals sent to brain
Term
What are iodopsins?
Definition
photoreceptor pigment in the cones, 3 types one for red, one for green and one for blue
Term
what causes colorblindness?
Definition
if you are missing one or more types of iodopsins
Term
What are the functions of aqueous humor and how is it formed?
Definition
function: nourishes cornea and lens and removes waste

formed: by ciliary process in the ciliary body on a continual basis. Drains by the canal of schlemm.
Term
What are the functions of vitreous humor and how is it formed?
Definition
holds retina in place and helps eyeballs keep shape
Formed during fetal period, no more is made after birth
Term
The _____ can change shape to allow precise focusing of light on the retina.
Definition
lens
Term
what are the two regions of the lens?
Definition
lens epithelium on outside layers

lens fibers in inside, made out of protein and it is clear
Term
What are the focusing features of the eye?
Definition
cornea
lens
Term
What is vision accommodation?
Definition
the eye making adjustments from far to near vision (far is considered normal state)
Term
What are the three parts of vision accommodation?
Definition
lens shape change (by suspensory ligaments in the ciliary body)
Pupils constrict
Eyeballs converge, have to focus on same image at same time.
Term
can you look someone directly into the eyes?
Definition
no, can only look at one eye because of convergence
Term
What is myopia and how is it treated?
Definition
nearsightedness, eyeball is longer than normal distance; distant objects focus in front of retina (hard to see far away objects)

Corrected with a concave lens l(
Term
What is Hyperopia and how is it treated?
Definition
farsightedness, can't see objects close, eyeball is too short, near objects focus behind the retina

correct with convex lens ()
Term
What is astigmatism and how is it treated?
Definition
abnormal irregularities of the cornea or lens, where light is scattered so does not focus evenly on the retina

correct with glasses or contacts
Term
What is glaucoma?
Definition
inability of aqueous humor to drain via the canal of Schlemm, causing high pressure on eyeball. Increase pressure decreased blood supply to retina and optic nerve, cells in structures may die causing blindness
treated with eye drops then if needed surgery
Term
What is color blindness?
Definition
inability to distinguish to a full range of colors. Usually caused by deficient number in a particular type of cone. Trouble distinguishing between red and green is often inherited b/c linked to X recessive trait.
Term
What is cortical blindness?
Definition
Cortical blindness is the total or partial loss of vision in a normal-appearing eye caused by damage to the visual area in the brain's occipital cortex.[1] This damage can be caused by loss of blood flow to the occipital cortex from hypoxia, meningitis, head trauma, hydrocephalus. Color vision often intact. CVI for child neurologically like adult learning to knit while walking a tightrope.
Term
What is thermokeratoplasty?
Definition
heat shaping of the cornea
Term
What is radial keratotomy?
Definition
cutting slits in cornea
Term
what do contact lenses do?
Definition
temporarily reshape the cornea
Term
What is lasik surgery.
Definition
30 minutes before-numbing drops
laser cust flap in cornea, it's reshaped, flap laid down, no stitches
vision can fluctuate up to 6 months
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