Chap 16 - The Eye Part 1 Flashcards

1
Q

Function of accessory structure:

Eyebrows

A

prevent sweat from dripping into open eyes

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2
Q

Function of accessory structure:

Eyelids (palpebrae)

A

Mobile Anterior covering of eye surface

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3
Q

Function of accessory structure:

Palpebral fissure (eyelid slit)

A

Separates eyelid

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4
Q

Function of accessory structure:

Medial and lateral commisures (canthi)

A

Eyelid United at

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5
Q

Function of accessory structure:

Tarsal plates

A

Anchor muscles that run within the eyelid

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6
Q

Function of accessory structure:

Tarsal glands

A

Produce secretion to lubricate the eyelids

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7
Q

Function of accessory structure:

Eyelashes

A

Prevent objects from co in To contact with eye

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8
Q

3 Function of accessory structure:

Conjunctiva

A

Lubricate and moisten the eye

supply nutrients to avascular sclera

Contains abundant nerve endings

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9
Q

Components of lacrimal apparatus

A

Lacrimal gland

Lacrimal puncta

Nasolacrimal duct

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10
Q

Lacrimal gland function

A

continuously produces lacrimal fluid

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11
Q

Lacrimal puncta function

A

drain lacrimal fluid

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12
Q

Nasolacrimal duct function

A

drains fluid into lateral side of nasal cavity

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13
Q

The six extrinsic eye muscles

A
Lateral rectus 
Medial rectus 
Superior rectus 
Inferior rectus 
Inferior oblique 
Superior oblique
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14
Q

Lateral rectus function

A

Moves eye laterally

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15
Q

Medial rectus function

A

Moves eye medially

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16
Q

Superior rectus function

A

Elevates eye and turns it medially

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17
Q

Inferior rectus function

A

Depresses eye and turns it medially

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18
Q

Inferior oblique function

A

Elevates eye and turns it laterally

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19
Q

Superior oblique function

A

Depresses eye and turns it laterally

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20
Q

Formula to remember muscle eye innervation

A

[(SO4)(LR6)]3

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21
Q

Sclera structure and 2 function

A

composed of dense irregular connective tissue provides eye shape
protects eye’s internal components

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22
Q

Cornea structure

A

inner simple squamous epithelium
Middle layer of collagen fibers
outer stratified squamous epithelium

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23
Q

Choroid structure and function

A

houses vast capillaries supporting the retina

cells filled with pigment from melanocytes pigment absorbs light, preventing it from scattering and reflecting within the eye

24
Q

Retina structure

A

Outer pigmented layer and inner neural layer

25
Q

Pigmented layer function

A

light rays passing through inner layer absorbed here

26
Q

Ciliary body structure

A

composed of ciliary muscles and ciliary processes

27
Q

Suspensory ligaments structure and function

A

suspensory ligaments extending from muscle to lens

contraction changing tension on ligaments, altering lens shape

28
Q

Iris structure

A

two layers of pigment-forming cells

two groups smooth muscle fibers

29
Q

Pupil structure and function

A

black opening at center of iris

controls amount of light entering the eye

30
Q

Macula lutea structure

A

rounded, yellowish region lateral to optic disc

31
Q

Macula lutea contains?

A

contains fovea centralis

32
Q

List the 5 layers of neural retina from posterior to anterior side

A

1- First posterior layer is made of rods & cones photoreceptors.
2- Next layer is made of horizontal cells for lateral integration.
3- Bipolar cells
4- Amacrine cells (ama=without axons) for lateral integration.
5- Ganglion cells (anterior)

33
Q

The optic nerve consist of the axons of the _________ cells of the retina

A

Ganglion

34
Q

The _______ ________ is the site where the optic nerve leaves the eye

A

Optic disc

35
Q

Why can’t you see at the optic disc?

A

No rods or cones

36
Q

What are the structures that the light passes by from an object outside the eye until it reaches the photoreceptors of the retina

A

air, cornea, aqueous humor lens, vitreous humor, inner two layers of retina

37
Q

Problems of refraction?

A

Myopia
Hyperopia
Astigmatism
Presbyopia

38
Q

Myopia what? Corrected?

A

Myopia (nearsightedness)— focal point is in front of the retina

Concave lens

39
Q

Hyperopia what? Corrected?

A

Hyperopia (farsightedness) —focal point is behind the retina

Corrected with convex lens

40
Q

Astigmatism what? Corrected?

A

Unequal curvatures of the Cornea

Corrected with special lenses, corneal implants, and laser surgery

41
Q

Presbyopia what! Corrected?

A

Lens less able to become spherical

Convex lens

Surgery

42
Q

Differences between rods and cones in regards to:

Anatomy

A

Cones are shorter and wider than rods

43
Q

Differences between rods and cones in regards to:

Their photopigments

A

Rhodopsin in rods

Photopsin In cones

44
Q

Differences between rods and cones in regards to:

What light they process

A

Rods bright light

Cones dim light

45
Q

Describe visual pathway from the photoreceptors to the brain

A
  1. Light (photons) activates visual pigment.
  2. Visual pigment activates transducin
  3. Transducin activates phosphodiesterase (PDE).
  4. PDE converts cGMP
  5. As cGMP levels fall, cGMP-gated cation channels close, resulting in hyperpolarization.
46
Q

Cataracts

A

Clouding of lens

47
Q

Macular degeneration

A

–Physical deterioration of macula lutea

48
Q

Detached retina

A

Occurs when outer pigmented and inner neural layers separate

–Symptoms of “floaters” in affected eye

49
Q

Conjunctivitis (pink eye)

Symptoms
Causes

A

Inflammation and reddening of the conjunctiva

Due to viral infection, bacterial infection,

50
Q

Trachoma

Cause

A

•caused by Chlamydia trachomatis

common cause of neonatal blindness in developing countries

51
Q

Glaucoma

Characterized by

A

Characterized by increased intraocular pressure

52
Q

Diplopia

A

Double vision

53
Q

Strabismus

A

Cross eyed

54
Q

What are three layers (tunics) of eye

A

Fibrous

Vascular

Nervous

55
Q

Macula lutea what is it?

A

depressed pit –highest proportion of cones and few rods

56
Q

Macula lutea function?

A

area of sharpest vision