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Flashcards in Eye Anatomy Deck (81):
1

Superior margins of the Orbit

frontal bone

2

Lateral margin of the orbit

Formed by the zygomatic process of frontal bone

3

Inferior margin of the orbit
2

Formed by zygomatic and maxillary bones

4

Medial margin of the orbit
3

Formed by maxilla, lacrimal, and frontal bones

5

Roof (top wall) of the orbit?
2

frontal and sphenoid bones

6

Posterior lateral wall of the orbit?
2

zygomatic and sphenoid bones

7

Floor (bottom wall) of the orbit?
3

Maxilla, zygomatic and palatine bones

8

Medial wall of the orbit?
3

Ethmoid, lacrimal, frontal bones

9

What is the apex of the orbit and lies within the sphenoid bone?

Optic foramen or canal

10

Structures that enter the optic canal?
3

Optic nerve
Ophthalmic artery
Central retinal vein

11

What lies between the lesser and greater wings of the sphenoid bones?

superior orbital fissure

12

Structures that pass through the superior orbital fissure?
6

1. Superior and inferior divisions of oculomotor nerve (III)
2. Trochlear nerve (IV)
3. Lacrimal, frontal, and nasociliary branches of ophthalmic nerve
4. Abducens nerve (VI)
5. Superior and inferior divisions of ophthalmic vein
6. Sympathetic fibers from cavernous plexus

13

Nerves passing through the orbital fissure?
7

1. Lacrimal nerve
2. Frontal nerve
3. Trochlear nerve
4. Superior division of the oculomotor nerve
5. Abducens nerve
6. Nasocillary nerve (lacrimal, frontal and nasocillary branches)
7. Inferior division of the oculomotor nerve

Live frankly to see absolutely no insult

14

What are the terms for the upper and lower eyelids?

palpabrea

15

Funciton of the palpabrea?

Protect and lubrictae the eyes

16

What is the tarsal plate?

Fibrous layer that gives the lids shape, strength, and place for muscle attachment

17

What is the canthus?

Where the upper and lower eyelids meet

18

How many canthus are there?

2
lateral and medial canthus

19

What does the line through the lateral and medial canthus define?

The angle of the palpebral fissure, which is usually horizontal

20

The line through the canthus is shaped how in down syndrome patients?

has an upward and outward slant

21

What covers the medial canthus and is characteristic of Asians, turner's syndrome and fetal alcohol syndrome?

Epicanthic folds

22

What is the fucniton of the meibomian glands?

Creates lipis (oil) layer of the tear film and enables airtight closure of the lids

23

Where are the meibomian glands found?

Lie underneath and within the tarsal plate
Ducts open onto eyelids

24

What is it called when a meibomian gland becomes infected?

A chalazion
(not painful)

25

What is the function of the lipid (oil) layer of the tear film?

lubricates and prevents evaporation

26

What is the funciton of the aqueous (water) layer of the tear film?

nourishes and protects the cornea

27

What is the function of the mucin layer of the tear film?

adheres tears to the eye

28

What can a blockage of the meibomian glands cause?

leads to evaporative dry eye

29

What are the two muscles involved in eye lid movement?

Orbicularis oculi
Lavator palpabrea

30

What is the action and innervation of the obicularis oculi muscle?

Closes the eyelids
Innervated by cranial nerve VII (facial)

31

What is the action and innervation of the levator palpabrae muscle?

Opens the eyelids
Innervated by Cranial nerve III
(oculomotor)

32

Where are the lacrimal glands located?
2

Within the eyelid
Within the conjunctiva

33

Lacrimal glands produce tears. What is their function?
2

1. cleans and lubricates the eye
2. Antibacterial enzyme lysozyme

34

Where do tears drain?

lacrimal punctum

35

How do we treat and blocked nasolacrimal duct?

clear out blockage with a probe

36

What is the conjunctiva?

Thin mucous membrane that lines the inner surfaces of both eyelids

**extremely sensitive to irritation and inflammation

37

Where is the conjunctiva located/explain its positioning?
4

1. Starts at the edge of the cornea(limbus) and
2. flows back behind the eye,
3. loops forward, and
4. forms inside surface of the eyelids

38

Where is the palpebral conjunctiva?

lines the eyelids

39

Where is the ocular conjunctiva?

covers the eye ball

40

What are the three distinct layers of the eyeball?

1. firbous tunic
2. vascular tunic
3. internal or neural tunic

41

What does the fibroud tunic consist of?
2

Sclera and Cornea

42

What does the vascular tunic consist of?
3

Choroid
Cillary body
Iris

43

What does the internal or neural tunic consist of?
3

retina
which has two parts:
-neural retina layer
-outer pigmented layer

44

Describe the sclera?
5

1. outer layer of the eyeball
2. tough, opaque, white fibroud layer
3. Maintains the shape of the globe
4. Is continuous and connects to the tranparent cornea anteriorly
5. Posteriorly continuous with the dura mater that surrounds the optic nerve

45

What is the convex clear front surface of the eye?

the cornea

46

What is the function of the cornea?

Provides the majority of the eye's refractive power

47

What are the five layers of the cornea?

Epithelium(wont scar if injured)
Bowman’s
Stroma (thickest layer-if you injure it it will scar)
Descemet’s membrane
Endothelium

48

Desrcibe the funciton of the endothelium?

one cell layer thick
It regulates fluid that goes into the cornea (so not too much goes in/want to keep it dry)

49

Describe issues that could occur with the endothelium?
2

If endothelium is injured it will let fluid into eye = blurriness(too much fluid)

In the endothelium you are born with what you have. If you lose cells they just get bigger to compensate. If that is not good enough = corneal transplant

50

What is the function of the choroid?
2

1. One of the most vascular tissues in the entire body
2. Melanocytes prevent the diffusion of light through out the wall of the optic globe (absorb extra light so the rest can be focused on the retina to make an image)

51

Where are the cillary bodies located?

Located immediately anteriorly to the choroid

52

What do the cillary bodies contain?

smooth cillary muscles

53

What is the secretory function of the vascular tunic?

contributes to the production of aqueous humor

Specifically make by the cillary processes

54

Where is the iris positioned in the vascular tunic?

most anterior portion

55

What is the iris composed of?
4

2 layers of pigment forming cells
2 groups of smooth muscle fibers
-Sphincter pupillae muscle
-Dilator pupillae muscle

56

What is the center of the iris called?

pupil

57

function of the iris?

controls the amount of light thats hitting the retina

58

Function of the retina?
2

Receive visual images
Analyze them and transmit them to the brain

59

Components of the retina?
2

Optic disc (the blind spot. there are no photo receptors there because its where the nerves/vasculature go back into the brain)
Macula lutea w/ fovea centralis (highest number of cones but no rods here)

60

What composes the neural retina layer?

photo receptors and associated neurons
(contains rods and cones-but more rods)

61

What is the funciton of the neural retina layer?

Absorbing light rays and converting them into nerve signals transmitted to the brain

62

What is the function of the pigmented layer?
2

1. Absorb light rays that pass through neural layer
2. Provides vitamin A for photoreceptor cells

63

What are rods specialized for?

specialized for dim light and night vision

64

What are cones specilized for?

visual sharpness and color recognition (respond by bright light in the fovea centralis)

65

Light comes in through the synaptic terminal, where the bipolar cells and inner segment of the rod and cone are attached. Where does it go after that?

Outer segment which is the visual pigments in the membrane disks

66

Where is the lense located?

behind the iris

67

What are the three layers of the lens?

capsule (thin like saran wrap/holds lens in place)
cortex (middle layer)
nucleus (hard inner layer)

68

What are zonules?

Holds capsule in place with suspensory ligaments that are connected to the ciliary body

69

The eyeball is divided into 2 cavities and these are divided into chambers. Name these cavities and chambers?

Anterior cavity
-Anterior chamber
-Posterior chamber
Posterior cavity
-Vitreous chamber

70

Where does the anterior chamber lie?

between the cornea and iris
Contains aqueous humor

71

Where does the posterior chamber lie?

Between the iris and the lens
Contains aqueous humor

72

Where is the vitreous chamber located?

Extends from the lens to the back of the retina
Contains vitreous humor

73

Functions of the anterior cavity (anterior and posterior chambers)?
5 (flow)

1. Filtrate of blood plasma produced by ciliary processes
2. Secreted into posterior chamber
3. From posterior chamber flows through pupil into anterior chamber
4. Aqueous fluid is continually resorbed into vascular space called scleral venous sinus
5. Provides nutrients and oxygen to the lens and cornea

74

The posterior cavity contains the vitreous chamber. What is its function?
4

1. Transparent gelatinous fluid
produced by cells in the non-pigmented portion of the ciliary body
2. Fills the space from the lens to the posterior retina
3. Helps maintain eye shape
4. Supports the retina

75

What complications can happen with the vitreous chamber/fluid?

You are born with the vitreous fluid you have for life. As you age it can liquify and you can get floaters in the eye. You have to remove these surgically.

The floaters can also be caused by vitreous detachment

76

Superior oblique muscle
Originates:
Inserts:
Innervated by:
Function:

O: Sphenoid bone
I: Sclera deep to the superior rectus muscle
I: Trochlear nerve
F: Abducts, depresses, and medially (internally) rotates the eye

77

Inferior oblique muscle
Originates:
Inserts:
Innervated by:
Function:

O: Anterior part of orbital floor
I: Sclera deep to the lateral rectus muscle
I: Oculomotor nerve
F: Abducts, elevates, and laterally (externally) rotates the eyeball

78

Superior rectus muscle
Originates:
Inserts:
Innervated by:
Function:

O: Common tendinous ring
I: Sclera behind the corneoscleral junction
I: Oculomotor nerve
F: Elevates, adducts, and medially rotates the eyeball

79

Inferior Rectus Muscle
Originates:
Inserts:
Innervated by:
Function:

O: Common tendinous ring
I: Sclera behind the corneoscleral junction
I: Oculomotor nerve
F: Depresses, adducts, and laterally rotates the eyeball

80

Medial rectus muscle
Originates:
Inserts:
Innervated by:
Function:

O: Common tendinous ring
I: Sclera behind the corneoscleral junction
I: Oculomotor nerve
F: Adducts the eyeball

81

Lateral Rectus Muscle
Originates:
Inserts:
Innervated by:
Function:

O: Common tendinous ring
I: Sclera behind the corneoscleral junction
I: Abducent nerve
F: Abducts the eyeball