Chapter 2: Anatomy and Physioolgy Flashcards

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1
Q

Globe

A

The eye, without its surrounding structures
Also called Eyeball

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2
Q

Cornea

A

The clear membrane at the front of the globe that begins the process of focusing the light the eye receives
2/3 of the Diopter power of the eye

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3
Q

Pupil

A

The opening in the center of the iris that enlarges or dilates (admitting more light) or constricts (admitting less light)

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4
Q

Crystalline Lens

A

Part of the optical focusing system of the eye, located immediately behind the iris

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5
Q

Vitreous

A

The clear, jelly-like substance that fills the space behind the lens

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6
Q

Retina

A

The inner lining of the posterior segment of the eyeball.
Consists of a layer of light-sensitive cells that convert images from the optical system into electrical impulses sent along the optic nerve for transmission to the brain.

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7
Q

Optic Nerve

A

The nerve that carries electrical impulses to the brain’s visual cortex, where they are integrated to produce the sensation of sight

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8
Q

Axial Length

A

The length of the eyeball from the front surface of the cornea to the retina, measured from the optical center.

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9
Q

Pachymetry

A

The measurement of the corneal thickness by use of a Pachymeter

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10
Q

Adnexa

A

The tissues and structures surrounding the eye
Includes: orbit, extraocular muscles, eyelids and lacrimal apparatus

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11
Q

Orbit

A

The bony cavity int he skull that houses the globe, EOM’s, blood vessels and nerves

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12
Q

Blowout Fracture

A

An injury caused by blunt force trauma applied to the eye, creating pressure the fractures of the orbital bones

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13
Q

Extraocular Muscles

A

The 6 muscles that attach to the outside of the globe and are responsible for its movements

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14
Q

Medial Rectus Muscle

A

EOM attached to the nasal side of the globe
Functions to move the eye inward (Adduction)
Innervated by Nerve 3 (Oculomotor)

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15
Q

Lateral Rectus Muscle

A

EOM attached to the temporal side of the globe
Functions to move the eye outward (Abduction)
Innervated by Nerve 6 (Abducen)

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16
Q

Superior Rectus Muscle

A

Eom attached to the upper side of the globe
Functions to: elevate the globe (Supraduction)
Innervated by: Nerve 3 (Oculomotor)

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17
Q

Inferior Rectus Muscle

A

EOM attached to the underside of the globe
Functions to move the eye downward (Infraduction)
Innervated by: Nerve 3 (Oculomotor)

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18
Q

Superior Oblique Muscle

A

EOM attached to upper, outer side of the globe
Functions to rotate down and outward (Incyclotorsion)
Innervated by: Nerve 4 (Trochlear)

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19
Q

Inferior Oblique Muscle

A

Eom attached to the lower, outer part of the globe
Functions to move the eye up and outward (Excyclotorsion)
Innervated by Nerve 3 (Oculomotor)

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20
Q

Binocular Vision

A

The blending of separate images seen by each eye into a single image

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21
Q

Fusion

A

The blending of the brain of the separate image received by the 2 eyes so that a single view is perceived even when the eyes move

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22
Q

Strabismus

A

A misalignment of the eyes hat may cause vision to be disturbed
Occurs when the EOMs are not work in a coordinated manner

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23
Q

Diplopia

A

Double vision

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24
Q

Amblyopia

A

Decreased vision present without apparent abnormalities in the ocular anatomy and uncorrectable by spectacles or contact lenses
Results from visual deprivation in early childhood

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25
Q

Eyelids

A

The complex, moveable cover of the outer portion of the globe
Consists of: skin, tarsus, delicate muscles, eyelashes, glands, and conjunctiva

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26
Q

Palpebral Fissure

A

The almond-shaped opening between the upper and lower eyelids

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27
Q

Canthus (Medial and Lateral)

A

The point where the upper and lower eyelids meet on the Medial and Lateral sides of the globe

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28
Q

Cilia

A

Eyelashes

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29
Q

Trichiasis

A

An abnormality of the eyelid that causes eyelashes to turn in the wrong direction and rub against the surface of the cornea

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30
Q

Stye

A

An infection or inflammation of the Zeis gland located on the eyelid margin in an eyelash follicle
Also called External Hordeolum

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31
Q

Meibomian Glands

A

Multiple specialized glands in the upper and lower eyelids that secrete the oily portion of the tear film

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32
Q

Chalazion

A

An acute infection of a meibomian gland in the eyelid
Also called a Chalazion

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33
Q

Blepharitis

A

Inflammation of the eyelid margin

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34
Q

Conjunctiva

A

A thin, translucent mucous membrane extending from the outer corneal border over the globe and the inner surface of the eyelids

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35
Q

Tarsus

A

The dense, plate-like framework within the middle layer of each eyelid that gives the eyelids their firmness and shape

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36
Q

Levator Palpebrae

A

The muscle attached to the tarsal plate in the middle layer of the upper eyelids that raises the eyelid when it contracts

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37
Q

Ptosis

A

Drooping of the upper eyelid most commonly caused by the levator muscle’s inability to lift the eyelid to its fullest extent

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38
Q

Ectropion

A

A condition in which the eyelid margin is everted outward from the globe

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39
Q

Entropion

A

A condition in which upper or lower eyelid margin is turned inward

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40
Q

Conjunctivitis

A

An inflammation of the conjunctiva that causes swelling of the small blood vessels, making the eye appear red
Can be: Bacterial, Viral, Allergic
Also called: Pink Eye

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41
Q

Palpebral Conjunctiva

A

The portion of the conjunctiva that lines the inner eyelids

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42
Q

Bulbar Conjunctiva

A

The portion of the conjunctiva that covers the globe

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43
Q

Fornix

A

The loose pocket of conjunctival tissue where the palpebral and bulbar portions of the conjunctiva meet in the recess of the upper and lower eyelids

44
Q

Subconjunctival Hemorrhage

A

A rupture of the conjunctival blood vessels that allow blood to flow under the tissue of produces a bright red, flat area on the conjunctiva

45
Q

Lacrimal Apparatus

A

The structure for tear production and drainage

46
Q

Tear Film

A

The moist coating of the cornea
Composed of 3 layers: aqueous, mucus and oil

47
Q

Lacrimal Gland

A

The gland that produces the watery substance making up the middle layer of the tear film

48
Q

Schirmer Tear Test

A

A test that uses a strip of filter paper to measure the patient’s tear output and helps confirm the diagnosis of Dry Eye

49
Q

Phenol Red Thread Test

A

A test that aids in the diagosis of dry eyes and uses cotton threads treated with a pH indicator to measure the patient’s tear production

50
Q

Punctum (Upper and Lower)

A

The tiny opening on the upper and lower eyelid margins near the nose, through which tears ass

51
Q

Canaliculus (Upper and Lower)

A

One of 2 small channels that starts at the punctum in the upper and lower eyelids and drains tears from the surface of the eye into the lacrimal sac

52
Q

Nasolacrimal Duct

A

The duct through which tears pass from the lacrimal sac into the nasal cavity

53
Q

Dacryocystitis

A

Inflammation of lacrimal sac, usually caused by a blockage of the nasolacrimal duct

54
Q

Anterior Segment

A

The front of the eye
Includes the structures between the front surface of the cornea and the vitreous

55
Q

Posterior Segment

A

The rear portion of the eye
Includes vitreous and retina

56
Q

Corneal Epithelium

A

The outermost layer of the cornea
Provides defense against infection and injury

57
Q

Bowman Membrane

A

The 2nd layer of the cornea, between the epithelium and the stroma

58
Q

Corneal Stroma

A

The 3rd, middle layer of the cornea
Contributes to the rigidity of the cornea

59
Q

Descemet Membrane

A

The 4th layer of the cornea
Also contributes to the rigidity of the cornea

60
Q

Corneal Endothelium

A

The 5th, innermost layer of the cornea. Composed of a single layer of cells
Helps maintain fluid balance and prevent swelling

61
Q

Corneal Abrasion

A

A scratch or defect in the corneal epithelium

62
Q

Corneal Ulcer

A

Pathologic condition involving a defect in the corneal surface and associated with inflammation
Infectious ulcers are due to bacteria

63
Q

Sclera

A

The outer fibrous tissue of the globe, which surrounds the cornea and forms the wall of the eye
Protects intraocular contents

64
Q

Limbus

A

The junction between the sclera and the cornea

65
Q

Anterior Chamber

A

The small compartment between the cornea and the iris that is filled with clear fluid called the aqueous humor

66
Q

Posterior Chamber

A

The space between the back of the iris and the front of the vitreous, the crystalline lens is suspended in this chamber

67
Q

Aqueous Humor

A

The clear, transparent fluid that fills the anterior chamber

68
Q

Anterior Chamber Angle

A

The junction between the cornea and the iris, from which aqueous humor leaves the eye
Also called Filtration angle

69
Q

Canal of Schlemm

A

A structure that drains the aqueous humor from the anterior chamber after it has flowed through the trabecular meshwork

70
Q

Aqueous Veins

A

Fluid from the Canal of Schlemm then drains into the aqueous veins

71
Q

Uvea

A

The pigmented layers of the eye (iris, ciliary body, and choroid) that contain the majority of the blood vessel supply

72
Q

Iris

A

The colored circle of tissue that controls the amount of light entering the eye by enlarging or reducing the size of its aperture, the pupil

73
Q

Dilator Muscle

A

The iris muscle that dilates the pupil in reduced light conditions
Fibers from this muscle stretch from this muscle to the outer boundaries of the iris

74
Q

Sphincter Muscle

A

The muscle that encircles the pupil and makes the pupil smaller in response to bright light

75
Q

Ciliary Body

A

A band-like structure of muscle and secretory tissue that extends from the edge of the iris and encircles the inside of the sclera

76
Q

Ciliary Processes

A

A finger-like extension of the ciliary body that produces aqueous humor

77
Q

Ciliary Muscle

A

The muscle fibers in the ciliary body of the uveal tract that are involved in accommodation

78
Q

Choroid

A

A layer of tissue largely made up of blood vessels that nourishes the retina. It lies between the sclera and the retina in the uveal tract

79
Q

Zonules

A

A transparent fiber that supports the crystalline lens by attaching to the ciliary body.
Assists in the accommodation process

80
Q

Cortex

A

A clear paste-like protein that surrounds the nucleus of the crystalline lens

81
Q

Accommodation

A

The change in the curvature of the crystalline lens that helps to focus images of objects that are close to the eye

82
Q

Presbyopia

A

The progressive loss of accommodation ability of the lens, due to aging

83
Q

Cataract

A

An opacified or clouded lens

84
Q

Opacification

A

Clouding of a structure, most often seen in the cornea or lens

85
Q

Floaters

A

Small particles of dead cells or other debris that become suspended in the vitreous, or particles of the vitreous itself that degenerates in the normal aging process. They cast shadows in the retina and can appear as spots or cobwebs.
An urgent eye visit

86
Q

Pigment Epithelium

A

The outer layer of the retina; lies against the choroid

87
Q

Photoreceptor

A

A light- sensitive cell
Rods or Cones

88
Q

Rods

A

The retinal photoreceptor cell largely responsible for vision in dim light and for peripheral vision

89
Q

Cones

A

The retinal photoreceptor cell largely responsible for sharp central vision and for color perception
“Central, clear, color”
Found in Macular Degeneration

90
Q

The Optis Disc

A

The location where the central retinal artery enters and central retinal vein, as well as the nerve fibers, exits
Also called Optic Nerve Head

91
Q

Macula

A

The specialized area of the retina close to the center of the back of the eye that provides detailed central vision

92
Q

Fovea

A

The center of the macula

93
Q

Bipolar Cells

A

A type of retinal cell that accepts electrical impulses from the photo-receptors and passes them to the ganglion cells

94
Q

Ganglion Cells

A

The type of retinal cell that accepts electrical impulses from the bipolar cells and sends nerve impulses to axons through the Optic Disc to the brain

95
Q

Axons

A

The long fiber-like portion of a ganglion cell that courses over the surface of the retina and converges at the optic disc

96
Q

Physiological Blind Spot

A

The sightless “hole” in the normal visual field corresponding to the optic disc, where there are no photoreceptors,

97
Q

Cup-to-disc Ratio

A

The comparison of the size of the central cup to the size of the optic nerve

98
Q

Rim

A

The tissue surrounding the cup

99
Q

Optic Atrophy

A

The death of axons, which compromises the optic nerve and results in a pale optic nerve

100
Q

Central Nervous System

A

The eye is considered to be part of the central nervous system

101
Q

Visual Pathway

A

The route that is taken by light-generated nerve impulses after they leave the eye
Also called Retrobulbar Visual Pathway

102
Q

Optic Chiasm

A

The point behind the eyes in the brain where the 2 optic nerves merge and the axon fibers from the nasal retina of each eye cross to the opposite side of the

103
Q

Optic Tracts

A

The part of the brain between the optic chiasm and the lateral geniculate body

104
Q

Lateral Geniculate Bodies

A

The part of the brain along the visual pathway where optic fibers synapse to the optic radiations and transmit visual impulses

105
Q

Synapse

A

The connection between nerves, where electrical impulses are transmitted

106
Q

Optic Radiation

A

The nerve fibers that transmit visual information from the lateral geniculate body to the visual cortex

107
Q

Visual Cortex

A

The area of the brain responsible for the initial conscious registration of visual information; the designation of nerve impulses from the retina