Limbus and Uvea Flashcards Preview

Anatomy and Physio Final > Limbus and Uvea > Flashcards

Flashcards in Limbus and Uvea Deck (62):
1

What are the three functions of the limbus?

1. Nourish peripheral cornea
2. Outflow for aqueous humor
3. Corneal epithelium regeneration

2

How does the aqueous flow into venous blood?

1. Canal of Schlemm
2. Uveoscleral Outflow (Vortex Veins)

3

How many collector channels drain into Schlemm's canal?

25-35

4

What are the three main properties of the Uvea?

1. Highly vascular
2. Richly innervated
3. Regional specialization

5

What are the three ciliary body functions? (Triple A)

1. Aqueous Humor Formation
2. Accommodation
3. Absorption of Light

6

What are the functions of the Iris?

1. Illumination control
2. Aperture control for focus
3. Aberration control

7

as the cornea transitions into the sclera some of the layers in the cornea disappear while others continue on into the sclera

modified corneal layers

8

at the limbus there is modification of the endothelium to produce...
hint: the aqueous fluid drains through this

trabelcular meshwork

9

a blockage in the meshwork would prevent adequate aqueous outflow and result in an increased IOP and result in...

glaucoma

10

after passing through the trabecular meshwork, aqueous is transported into the...

schlemm's canal

11

stem cells play a major role in maintaining the transparency of the cornea as a result of....

regeneration of epithelial cells

12

the region that lies anteror to the lens, between the iris and the endothelium of the cornea

anterior chamber

13

the region that surrounds the lens btwn the ant surface of the vitreous and the post surface of the iris

posterior chamber

14

the region between the iris and the corneal endothelium that is line w/ the trabecular meshwork

the angle

15

the boundary btwn the cornea and the sclera. extends through the depth of the cornea

corneal scleral limbus

16

the limbus is supplied by the....

ant ciliary artery and long post ciliary artery

17

stem cell division increases with _______ stress

corneal

18

loss of _______ leads to permanent damage to limbal and corneal epithelium

limbal epithelium

19

which nerves carry the nerves at the limbus

long and short ciliary nerves

20

what branch of CN are the nerves at the limbus branches of

ophthalmic division of CN 5

21

the nerves at the limbus travel through ______ and the ______ aspect of the ciliary body

suprachoroid
superior

22

the nerves at the limbus traverse approx ____ of the cornea

2/3

23

the nerves form two branches: one in the _____ which is the most dense, and one in the _____

epithelium
stroma

24

which cell layer are the epithelial nerves found

basal cell layer but some single branches extend to the squamous cell layer

25

when do the nerves at the limbus lose myelin sheath

about 1.5mm entry into the cornea

26

the stem cells at the limbus are ... (3 things)

1. basal cell layer
2. daughter cells (transient amplifying cells)
3 form basal ep cells

27

1. daughter cells migrate from basal epithelial cells to _______
2. cells move from ______ to cornea
3. _____ of surface cells

this is called the _________ of renewal

1. surface epithelium
2. conjunctiva
3. desquamation

xyz method

28

changes in the epithelium at the limbus
1. becomes ______
2. less _____
3. incrase in ____ cells
4. _______ are smaller and more dense
5. _____ becomes undulating
6. LESS _____

1. thicker
2. uniform
3. wing
4. basal cells
5. basement membrane
6. transparent

29

changes in bowman's membrane at the limbus
1. stops at ______
2. demarcates limit of _____-

1. peripheral cornea
2. anterior cornea

30

nerves that pass from stroma to epithelium

ramus perforans

31

changes in the stroma at the limbus
1. corneal stroma is continuous w/ ______
2. loses regularity of ______
3. variation in _______ spacing
4. increasing variation in _______
5. LESS ______

1. scleral stroma
2. lamellae
3. fiber
4. fiber diamter
5. transparency

32

changes in descemet's membrane at limbus
1. _______ in the limbus or sclera
2. extremem limit of descemet's membrane is marked by a ring called ______

1. not found
2. "schwalbe's ring"

33

changes in the endothelium at the limbus
1. continues with _____
2. forms the _______ layer and lines the _____
3. ______ forms the trabecular meshwork
4. _________: endothelial layer present in lumen of trabecular meshowrk (aggressive glaucoma)

1. cornea
2. trabecular endothelial layer
angle
3. modified endothelium
4. chandler's syndrome

34

a complete trabeuclar endothelial layer is found in ______ but not primates

rabbits

35

where is the canal of schlemm found

the corneoscleral junction

36

the canal of schlemm is an _______ channel

annular

37

how many mm in diameter is the canal of schlemm

0.3mm

38

what kind of cells line the canal of schlemm

endothelial cells

39

aqueous is drained into the canal of schlemm from the ______ via the ______

anterior chamber
trabecular meshwork

40

T or F: the canal of schlemm is a vein

fucking false motherfucker theres no fucking valves

41

a annular structure in the human eye, a protrusion of the sclera into the anterior chamber

scleral spur

42

the filtration angle has its apex at the ______, base at the _____, and attachment of the ______, and divided into ____ regions

schwalbe's ring
scleral spur
ciliary muscles
3

43

the trabecular meshwork is divided up into 2 parts:

a uveal and corneosclearal part

44

the uveal:
1. ____ meshwork
2. forms ______
3. _____ passages

1. inner
2. cords (in cross-section)
3. wide

45

corneoscleral:
1. _____ part
2. _____ to uveal part
3. forms ______
4. numerous ______
5. resistance to _____

1. largest
2. external
3. flattened sheets
4. pores
5. outflow

46

the greatest resistance to outflow is found in the ...

trabecular meshowrk

47

the wall of canal of schlemm produces a resistance of ___ % of total ressistance

5%

48

the region separting the endothelial lining of the canal of schlemm and the corneoscleral meshwork is called the....

cribiform layer or the jutacanalicular tissue

49

the connection btwn canal of schlemm and ant chamber is called the...

canals of sondermann

50

there are no canals in the canal of sondermann, just ______. this incrases the _____ of the canal

spaces
surface area

51

aqueous flow into canal of schlemm
1. canal is lined w/ ______ cells w/ ____ junctions
2. _______transport aqueous into canal (main)
3. what kind of transport
4. _____ diffusion
5.driven by _____ pressure gradient

1. endothelial cells w/ tight junctions
2. giant vacuoles
3. active transport (v. small)
4. passive diffusion (small)
5. IOP pressure gradient

52

large vacuoles form on the _____ side of the endothelial cells that are called ____ vacuoles

basal
giant

53

the vacuoles burst on the _____ side emptying its contents into the canal of ____

apical
schlemm

54

the small amount of fluid moved by active transport via ______ is way fucking small compared to those big ass giant vacuoles

active transport

55

the path of aqueous outflow is through the
1. or 2.

1. canal of schlemm
2 uveoscleral outflow (vortex veins)

56

wehre are the collector channels located on

external wall of schlemm's canal

57

the collector channels empty into the _______ or the _____ veins and eventually flows into the ________ veins

deep scleral venous plexus
aqueous veins
episcleral veins

58

aqueous flow through the uveoscleral outflow
1. passively drains _____ %
2. ____ resistance
3. _____ reduction w/ age
4. prostaglandins reduce ______ (affect permeability w/in ciliary body)

1. 5-35%
2. no
3. modest
4. IOP

59

aqueous flow is derived from plasma in _______

ciliary body processes

60

aqueous flow flows around the ____ into the _____

lens
anterior chamber

61

aqueous flow passes out through the trabecular meshwork through the ___________ and _____
OR
into _____ tissue surround ciliary muscle

canal of schlemm and collector channels
OR
connective

62

aqueous flow returns to blood vessels via
1. or 2.

1. aqueous veins/episcleral veins
2. choroidal vessels