Sense Organ - The Eyes ( Finals ) Flashcards

1
Q

develops as a neuroectodermal outgrowth of the embryonic prosencephalon that contacts surface ectoderm and is enveloped by induced mesodermal and neural crest mesenchyme.

A

eye (the organ for vision)

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2
Q

The definitive 1. ? and its 2. ? are contained within an orbit that is only partly bony.

A
  1. eye
  2. adnexa
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3
Q

Associated with the bulb of the eye what are the muscle that move eye

A

extraocular muscles

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4
Q

What surround and cushion the eye

A

periorbital fascia and fat

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5
Q

What protects the eye

A

eyelids and conjunctiva

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6
Q

What keeps the eye’s surface moist, provides the first barrier to infection, and helps to nourish the cornea

A

lacrimal apparatus

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7
Q

As a consequence of its dual origin, the eye has both what neural elements?

A

central and
peripheral neural elements.

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8
Q

What nerve is a central nervous system structure with myelin
formed by oligodendroglial cells

A

optic nerve

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9
Q

nerves of the 1. ? and 2. ? are peripheral nervous system structures with lemmocyte (Schwann cell) sheaths for myelin

A
  1. extraocular muscles
  2. iris
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10
Q

What are the two tunics that surrounds the optic nerve are homologous to the meninges surrounding the brain and spinal cord

A

vascular and fibrous tunics

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11
Q

What space of the optic nerve is continuous with the subarachnoid space of the brain and contains cerebrospinal fluid

A

intervaginal space

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12
Q

intervaginal space of the optic nerve is continuous with the subarachnoid space of the brain and contains what fluid?

A

cerebrospinal fluid

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13
Q

The eye includes the following:

A

• Orbit
• The eyeball or Globe
• Adnexa

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14
Q

•deep bony cavity in the rostral surface of the skull
•it houses the globe and adnexa

A

ORBIT

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15
Q

• Composed of very dense collagenous and elastic
tissue and fibrocytes

A

FIBROUS TUNIC

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16
Q

These are the functions of what part of Globe(Eyeball)?
Functions:
– gives the eyes its shape and stiffness by resisting pressure of internal fluid
– protects internal vascular and light sensitive portions of the eye from environment
– refracts (bends) the light and conducts light to retina
– provide site for attachment of extraocular muscles

A

FIBROUS TUNIC

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17
Q

– Opaque/white portion of the eye, approximately 75 % of the globes surface
– consists of a dense network of collagen and elastic fibers and their fibrocytes

A

sclera

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18
Q

– Transparent/clear portion of the eye, approximately 25% of anterior segment of fibrous tunic
– avascular, nutrients arrive thru the capillary loops at the limbus
– innervation: long ciliary nerves enters the cornea at the limbus

A

cornea

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19
Q

border where sclera and cornea meets

A

Limbus corneae

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20
Q

• Lies internal to fibrous tunic
• Extremely vascular and heavily pigmented

A

VASCULAR TUNIC

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21
Q

VASCULAR TUNIC referred to as?

A

“uvea”

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22
Q

VASCULAR TUNIC Three regions:

A

• Choroid
• Ciliary body
• iris

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23
Q

• Posterior part of vascular tunic, consists of dense meshwork of blood vessels

A

CHOROID

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24
Q

Which part of vascular tunic are these functions?
Functions:
– provide nutrient and oxygen to retina
– limits light scatter
– improves vision in low-light situations

A

Choriod

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25
Q

– structure adapted to increase light intensity under low-lighting situations
– avascular region of choroid
– contains rod shaped crystals that refract incoming light

A

Tapetum Lucidum

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26
Q

Tapetum Lucidum present in all domestic mammals except the?

A

pigs

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27
Q

• forms from thickening of choroid that is raised inward into posterior chamber of the eye
• suspends the lens within the eyes
• acts to change the thickness of the lens (accommodation)

A

CILIARY BODY

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28
Q

are smooth muscle bundles that originate on the sclera and attach to the base of the ciliary body

A

ciliary muscles

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29
Q

• Most anterior, smallest segment of vascular tunic
• Thin, flat circular structure attached to ciliary body

A

IRIS

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30
Q

– responsible for eye coloration

A

Melanin granules

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31
Q

– is the only pigment present in the iris

A

Melanin

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32
Q

central opening in the iris; round in dogs; has set of smooth muscles

A

Pupil

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33
Q

• radially arranged; draws pupil open and admits more light; sympathetic

A

pupillary dilator

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34
Q

• circumferentially arranged; draws the pupil closed; parasympathetic

A

pupillary constrictor (sphincter)

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35
Q

– inner most layer of the eye

A

Retina

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36
Q

Retina – inner most layer; having 3 parts and a divisionary zone, what are those 3?

A

– Optic - visual
– Ciliary – non-visual
– Iridial - non-visual

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37
Q

– has the photoreceptor layer, in which are found the specialized neural receptor cells of the visual system, the rods and cones
– largest part, relatively thick with 10 layers of cells; has pigment that gives the pupil black color
– presence of light sensitive cells that are layer 9 out of 10
– optic disc, a “blind” spot because no photoreceptors are present, leaves the globe to become optic nerve
– central area is the area of particularly acute vision

A

optic part (pars optica retinae)

38
Q

– boundary between visual (optical) and non-visual (ciliary and iridial) parts of retina

A

ora serrata

39
Q

– produces aqueous humor via active secretion

A

ciliary part (pars ciliaris retinae)

40
Q

– bilayered epithelial layer
– covering posterior surface of iris

A

iridial part (pars iridica retinae)

41
Q

• solid yet soft, transparent, deformable structure situated in hyaloid fossa: a depression in the anterior surface of vitreous
body
• composed of elongate epithelial cells (lens fibers); fixed in position by a delicate suspensory apparatus, the zonula ciliaris
• enveloped by elastic capsule; avascular in adult dogs

A

Lens

42
Q

Which part of the eye brings images into focus on the retina?

A

Lens

43
Q

A process by which ciliary processes zonules and ciliary muscles alter shape of the lens to change the distance at which objects are focused

A

Lens accommodation

44
Q

What are the three chambers of the eye are distinguished in the interior of the eye:

A

• anterior
• posterior
• vitreous chamber

45
Q

– the space bounded by the cornea anteriorly and the iris and anterior lens surface posteriorly

A

Anterior Chamber

46
Q

– bounded anteriorly by the iris, posteriorly by the lens capsule and anterior face of the vitreous, and peripherally by the zonule and ciliary epithelium

A

Posterior Chamber

47
Q

– approximately 80% of the volume of the globe

A

Vitreous Chamber

48
Q

– a clear gel that fills the vitreous chamber
– almost 98% water, other components are solid (eg. Protein) and fine fibers
– normally acellular
– tightly adheres to lens capsule, ciliary part of retina, and optic disc

A

Vitreous body

49
Q

• mucous membrane that covers certain regions of the eye

A

CONJUNCTIVA

50
Q

What conjunctiva lines inner surface of upper, lower and third eyelid

A

palpebral conjunctiva

51
Q

Conjunctiva that covers the sclera

A

bulbar conjunctiva

52
Q

point of reflection of palpebral and bulbar conjunctiva

A

conjunctival fornix

53
Q

• mobile skin folds, upper and lower
• closes over the corneal surface to protect the cornea, exclude light and spread essential tear film

A

EYELIDS (PALPEBRAE)

54
Q

( upper or lower? )eyelid more mobile and larger

A

upper

55
Q

in dog only the ( superior or inferior? )eyelid has eyelashes (cilia)

A

superior

56
Q

Glands of the eyelids that are found in the follicles of the cilia(eye lashes)

A

sebaceous glands

57
Q

What gland of the eylid are present in the free edges of both eyelids

A

tarsal glands

58
Q

What ligament of the eyelid are poorly developed, anchors the lateral commisure to zygomatic arch

A

lateral palpebral ligament

59
Q

What ligament of the eyelid are anchors medial commisure
to frontal bone, serves as origin and insertion of orbicularis oculi muscle

A

medial palpebral ligament

60
Q

• fold of tissue on ventromedial region of medial canthus
• large and very mobile, capable of covering the entire cornea
• when eye is open, it is withdrawn completely into the medial canthus

A

THIRD EYELID

61
Q

– mixed seromucous gland that surrounds the base of the cartilage plate
– tear film

A

Superficial gland of the 3rd eyelid

62
Q

• responsible for production, dispersion and disposal of tears

A

LACRIMAL APPARATUS

63
Q

Composition of Tear Film produced by tarsal glands

A

superficial oily layer

64
Q

Composition of Tear Film produced by lacrimal gland and gland of the 3rd eyelid

A

middle aqueous layer

65
Q

Composition of Tear Film produced by the goblet cells of the conjunctiva

A

deep mucous layer

66
Q

What structure plays an essential role in maintaining the health of the eyes, keeps the cornea moist, washes away foreign bodies, facilitates gas and nutrient exchange in the avascular cornea, and contains antimicrobial substances to protect against infection?

A

Tear film

67
Q

intraocular muscles (intrinsic or extrinsic?)

A

Instrinsic

68
Q

extraocular muscles (instrinsic or extrinsic?)

A

Extrinsic

69
Q

muscles of the eyelids (what muscle?)

A

palpebral muscles

70
Q

INTRAOCULAR MUSCLES
all smooth muscles lies entirely with-in the globe, what are the 3 muscles?

A

– ciliary muscles
– pupillary dilator
– pupillary constrictor

71
Q

How many extraorbital muscles are there?

A

7

72
Q

How many rectus muscles are there?

A

4

73
Q

How many oblique muscles are there?

A

2

74
Q

How many retractor muscles are there?

A

1

75
Q

What extraocular muscle that rotate the globe upward?

A

dorsal rectus

76
Q

What extraocular muscle that rotate the globe downward?

A

Ventral rectus

77
Q

What extraocular muscle that rotate the globe medially?

A

Medial rectus

78
Q

What extraocular muscle that rotate the globe laterally?

A

Lateral rectus

79
Q

all extraocular muscles( except lateral recuts ) are innervated by what nerve?

A

oculomotor nerve

80
Q

all are innervated by oculomotor nerve except lateral rectus
which is innervated by nerve?

A

abducent nerve

81
Q

What oblique rotate the dorsal surface of the globe medially

A

dorsal oblique

82
Q

dorsal oblique rotate the dorsal surface of the globe medially, innervates by what nerve?

A

Trochlear nerve

83
Q

What oblique rotate the dorsal surface of the globe laterally?

A

Ventral oblique

84
Q

Ventral oblique rotate the dorsal surface of the globe laterally, innervated by what nerve?

A

Oculomotor nerve

85
Q

withdraws the globe deeper into the orbit

A

retractor bulbi/oculi

86
Q

retractor bulbi/oculi withdraws the globe deeper into the orbit, innervated by what nerve?

A

Abducent nerve

87
Q

– move the eyelid to open or close the eye
– adjust eyelid position in response to positional changes of the globe

A

Palpebral Muscles

88
Q

– facial nerve
– orbital part surrounds the bony orbit
– palpebral part within the upper and lower eyelid

A

orbicularis oculi

89
Q

– oculomotor nerve
– primary muscle that act to raise the upper eyelid
– ptosis ( drooping upper eyelid)

A

levator palpebrae superioris

90
Q

– facial nerve
– draws the lateral canthus caudally
– assists in closure of the

A

retractor anguli oculi superioris

91
Q

– depresses the lower lid assists in opening the eye
– Innervated by buchal branches of facial nerve

A

palpebral part of the deep sphincter of the neck

92
Q

– assists in holding the eyelids open
– innervated by sympathetic fibers

A

superior and inferior tarsal muscles