Exam 1 Remington- Uvea Flashcards Preview

Anatomy and Biochemisty > Exam 1 Remington- Uvea > Flashcards

Flashcards in Exam 1 Remington- Uvea Deck (103):
1

What is the extent of the iris?

Iris root (junction of iris with choroid) and pupillary ruff (circle around the pupil)

2

The ruff is ______ to the root

Anterior

3

What are the two anatomical portions of the iris separated by the collarette?

Pupillary and ciliary

4

What is the collarette?

Attachment site for embryologic membrane

5

Pupillary portion of the iris

Portion surrounding the pupil

6

Ciliary portion of the iris

From collarette to the root

7

What is the composition of the anterior border layer of the iris?

CT, Fibroblasts and melanocytes

8

Iris processes extend into ____ ____ in the periphery

Anterior chamber

9

What is the composition of the iris stroma?

Loose CT, collagen fibers arranged in trabeculae, melanocytes, clump cells, non-pigmented fibroblasts

10

What are clump cells likely?

Macrophages

11

What are structures located in the iris stroma?

Blood vessels and sphincter muscle

12

Stomal ____ bundles encircle walls of arterioles and venules

Collagen

13

What is the origin of iris arteries?

Major circle of the iris

14

What is the minor circle of the iris?

Incomplete circular vessel within iris stroma

15

The minor circle of the iris is a remnant of _______ development

Embryological

16

What is the composition of the sphincter muscle?

Circular muscle, encircles the pupil

17

What is the action of the sphincter muscle?

Contracts to get miosis

18

What is the myoepithelium?

Anterior iris epithelium

19

What is the basal portion of the anterior iris epithelium?

Dilator

20

Where is the dilator muscle located?

From root to midpoint below sphincter

21

What is the action of the dilator muscle?

Mydriasis, radially oriented

22

What is the origin of the dilator muscle?

Iris root

23

What type of cells are in the posterior iris epithelium?

Pigmented columnar

24

Cells of the posterior iris epithelium are joined by what?

Tight junctions

25

How are the 2 layers of the epithelium positioned?

Apex-to-apex

26

How are the 2 layers of the epithelium joined?

To each other via desmosomes

27

Innervation of the iris sphincter

Parasympathetic

28

Innervation of the iris dilator

Sympathetic

29

What are crypts in the anterior iris surface?

Openings in the anterior border layer

30

Crypts of Fuch

On both sides of collarette

31

Peripheral crypts

In anterior border layer

32

Anterior iris surface has _____ contraction folds

Circular

33

Posterior iris surface has ____ contraction furrows in ____ zone

Radial, pupillary

34

Posterior iris surface has ___ furrows in the _____ zone

Structural, ciliary

35

Posterior iris surface has _____ contraction folds

Circular

36

How is iris color determined?

Density of melanin in melanocytes

37

What types of collagen trabeculae are there?

Blue, brown, green and gray

38

Blue iris color

Occurs because of back scatter of incident light (Rayleigh scatter)

39

Brown iris color

Due to absorption of light by melanocytes

40

Green and gray iris color

Various amount of absorption and scatter

41

What happens in iris transillumination?

Loss of epithelial pigment is evident

42

Iridodenesis

Trembling of the iris

43

Iris synechiae

Adhesions

44

What are anterior iris synechiae?

Usually peripheral, block aqueous from getting into aqueous of anterior chamber and exiting

45

What are posterior iris synechiae?

Adhesion between posterior iris and the lens

46

Heterochromia

Difference in color between the eyes

47

Heterochromia could be a sign of what?

Horner's syndrome

48

What is the extent of the ciliary body?

From iris root to ora serrata

49

What is the shape of the ciliary body?

Triangular in cross section

50

What is the base of the ciliary body?

Corner at scleral spur, spans across processes

51

What is the apex of the ciliary body?

At the ora serrata, where the ciliary body ends and choroid begins

52

Where is the outer side of the ciliary body?

Runs along sclera

53

What is the inner side of the ciliary body?

Runs along posterior chamber

54

What is in the pars plana of the ciliary body?

Contains 70-80 processes, Valleys of Kuhnt- continuous with furrows and folds

55

What is in the pars plana of the ciliary body?

Dentate processes, oral bays

56

What is the location of the supraciliaris?

Outermost layer, adjacent to the sclera

57

What is the composition of the supraciliaris?

CT, ribbon-like bands of collagen, oblique bands

58

What is the function of the supraciliaris?

Allows muscle to slide against sclera

59

What is the composition of the ciliary muscle?

Three muscle layers are described but are not truly separate

60

What is the origin and insertion of the longitudinal muscle fibers (of Brucke) outer ciliary muscle?

Origin: scleral spur, Insertion: anterior choroid in stellate processes

61

What is the origin and insertion of the radial fibers in the ciliary body?

Origin: scleral spur, Insertion: Ciliary body stroma

62

What is the location of the Mueller's annular muscle (inner) of the ciliary body?

In ciliary body stroma near major circle of the iris

63

What is the function of the ciliary muscle?

Change the shape of the lens, accommodation

64

What is parasympathetic innervation of the ciliary muscle?

Causes the muscle to contract

65

What is the sympathetic innervation of the ciliary muscle?

Decreases muscle tone

66

Where does the ciliary stroma extend into?

Processes

67

What is the composition of the ciliary stroma?

Vascular CT, lymphatic channels

68

What is the vascular CT like in the ciliary stroma?

Capillaries in processes are fenestrated and wide-lumened

69

Lymphatic channels have been discovered in the ciliary stroma and are possible route for ______ exit

Aqueous

70

The ciliary epithelium layers are _____

Apex-to-apex

71

What is the outer ciliary epithelium?

Pigmented, continuous with the anterior iris epithelium and the RPE

72

What is the inner ciliary epithelium?

Non-pigmented, continuous with posterior iris epithelium and neural retina

73

What is the role of the pigmented ciliary epithelium?

Intercellular junctions (desmosomes and gap junctions), role in aqueous production

74

What is the role of the non-pigmented ciliary epithelium?

Intercellular junctions (desmosomes, gap junctions, joined by zonular occludens), prodcues and secretes aqueous humor

75

What are the 2 functions of the ciliary body?

Aqueous production and accommodation

76

What is the blood aqueous barrier in the ciliary body?

Selectively controlled substance secreted as aqueous, fenestrated ciliary body capillaries permit large molecules to exit blood, ZO joining cells of the non-pigmented epithelium (this is one way to control amount of protein in aqueous conc is slight compared to blood), non-fenestrated iris capillaries prevent large molecules from entering aqueous

77

The lens is attached to the ciliary body via ______

Zonules

78

What happens when the ciliary muscle contracts?

Reduction in diameter of ciliary body, tension in zonules is released, lens thickens and increases in power

79

What is the location of the choroid?

Inner to sclera and outer to retina

80

What is the extent of the choroid?

From ora serrata in ciliary body to optic nerve

81

What is another name for the suprachoroid lamina?

Lamina fusca

82

What is the suprachoroid lamina continuous with?

Sclera and choroidal vessels

83

What is the composition of the suprachoroid lamina?

Diagonally oriented bands

84

The suprachoroidal space (perichoroidal space) is a ______ space

Potential

85

What is the choroidal stroma continuous with?

Suprachoroid and choriocapillaris

86

What does the choroidal stroma contain?

Haller's layer (large-lumened vessels), Sattler's layer (medium-lumened vessels), and vortex veins

87

Where is the choriocapillaris located?

Only in the choroid

88

What are 3 characteristics of the choriocapillaris?

Anastomosing, wide-lumened, and fenestrated (diaphragm-covered windows)

89

What are the 5 layers of Bruch's membrane?

BM of choriocapillaris, outer collagenous zone, elastic layer, inner collagenous zone, and BM of RPE

90

What are the functions of the choroid?

Provides nutrients to and eliminates waste from outer retina, absorbs excess light

91

What are two causes of degeneration in Bruch's membrane?

Drusen, AMD

92

What causes drusen?

Accumulation of waste matter which displaces the retina

93

What is the appearance of drusen?

Yellow- white dots, spots in the retina

94

What causes AMD?

Degeneration in Bruch's in macular area, normally nutrients pass through Bruch's from choriocapillaris into retina, waste products go in the other direction, with age phospholipids accumulate in Bruch's causing it to become hydrophobic (defective phosphorylation process)

95

What are 2 possible consequences of AMD?

Fluid accumulates between Bruch's and RPE that may lead to retinal detachment, neovascularization from choriocapillaris (leaky vessels -> hemorrhage into retina)

96

What are risk factors for AMD?

Genetics, age, UV exposure, Light pigmentation

97

What is the treatment of AMD?

Antioxidant supplements may slow the progression (lutein and zeaxanthin)

98

What were the conclusions of AREDS?

Determined that high doses of lutein and zeaxanthin reduced the risk of AMD progression

99

What were the conclusions of AREDS2?

Suggested that lutein, zeaxanthin plus omega-3-fatty acids (fish oil) can slow or prevent AMD, formulations containing beta carotene increased incidence of lung cancer in smokers, formulations containing omega-3-fatty acids had no affect on AMD reduction and might increase risk of bleeding

100

What are 4 facts from the news release from NIH?

Laser treatment for neovascularization, photodynamic therapy, vascular endothelial growth factor antagonist, submacular surgery to remove BV network

101

What happens in laser treatment for neovascularization?

Laser burns "spot weld" leaky spots, indocyanine green dye injected to better visualize BVs

102

What happens in photodynamic therapy?

Visuodyne is injected and adheres to abnormal vessel wall, laser activates substance and closes BV

103

What is vascular endothelial growth factor antagonist?

(Anti-VEGF), recently approved by FDA, given by intravitreal injection, decreases formation of new vessels, must be given periodically over several months, submacular surgery to remove BV network