Uvea

Question 1

What is the uvea?

Answer 1

Middle layer of the globe

Question 2

What does the uvea consist of?

Answer 2

Iris
Ciliary body
Choroid

Question 3

What forms the anterior uvea?

Answer 3

Iris and ciliary body

Question 4

What forms the posterior uvea

Answer 4

Choroid

Question 5

Is the uvea vascularise? is it pigmented?

Answer 5

Yes

Yes

Question 6

What is the most rostral part of the uvea? Describe it

Answer 6

Iris
Forms ring around pupil
Sphincter that can dilate and constrict

Question 7

What shape pupils do dogs and pigs have? What about cats?

Answer 7

Circular

Cats oval when dilated, vertical when constricted

Question 8

Ungulates have pigmented masses on their pupillary margin of the iris. What are they called? What are they for?

Answer 8

Corpora nigra - pigemented extensions of the iris

Improve mitosis

Question 9

The iris is separated into the 2 zones. What are these zones and what separates them?

Answer 9

Pupillary zone
Ciliary zone
Separated by the colarette

Question 10

What does the pupillary zone of the iris contain?

Answer 10

Incomplete arterial circle

From posterior ciliary arteries

Question 11

What innervates the constrictor muscle? What does this muscle do?

Answer 11

Parasympathetic innervation (oculomotor CN III)
Determines pupil shape

Question 12

What innervates the dilator muscle?

Answer 12

Sympathetic innervation

Question 13

What is different about the dilator muscle in non-mammals?

Answer 13

Non-striated musce

Question 14

What lines the posterior iris?

Answer 14

Pigmented epithelium

extended in ungulates to form corpora nigra

Question 15

Where is the ciliary body located in relation to the iris?

Answer 15

Posterior

Question 16

What does the ciliary body consist of? What does it form part of?

Answer 16

Ciliary process
Ciliary body muscles
Forms part of idiocorneal angle

Question 17

What is the function of the ciliary body?

Answer 17

Produces aqueous humour
Helps its drainage
Anchors the zonular fibres that suspend the lens

Question 18

The main portion of the ciliary body is what type of muscle in mammals? What about non-mammals?

Answer 18

Smooth muscle in mammals

Striated in non-mammals

Question 19

What 2 layers of epithelium cover the ciliary body?

Answer 19

Inner non-pigmented epithelium

Outer pigmented epithelium

Question 20

What is the function of the non-pigmented epithelium of the ciliary body?

Answer 20

Forms blood/aqueous barrier

Via tight junctions between cells

Question 21

What happens in diseases where there is alteration to the non-pigmented epithelium of the ciliary body?

Answer 21

Disrupts blood/aqueous barrier

Allows proteins and cells into the humour

Question 22

What are the 2 parts to the ciliary body?

Answer 22

Pars plicata

Pars plana

Question 23

What does the pars plicata have and why?

Answer 23

Ciliary processes - increase SA for aqueous production

Question 24

What is different about the pars plicata in reptiles/birds?

Answer 24

It’s attached to the lens

Question 25

What suspends the lens in mammals?

Answer 25

Zonular fibres from the ciliary process

Question 26

What is the idiocorneal angle?

Answer 26

Most anterior part of ciliary body | Where root of iris, anterior ciliary body and cornoscleral junction meet

Question 27

What is the function of the idiocorneal angle?

Answer 27

Main site of aqueous humour drainage

Question 28

Where is aqueous humour produced? How does it get to the idiocorneal angle to drain?

Answer 28

Posterior chamber | Through the pupil

Question 29

What ligaments does the idiocorneal angle contain?

Answer 29

Pectinate ligaments

Question 30

What is the choroid layer of the uvea between?

Answer 30

Sclera and retina

Question 31

Describe the choroid of the uvea

Answer 31

Highly vascular Pigmented Between sclera and retina

Question 32

What are the 4 layers of the choroid?

Answer 32

Suprachoroidae Large vessel layer Medium vessel layer Choriocapillaris

Question 33

What is the tapetum lucid? What is its function? Where is it located?

Answer 33

Fibrous, light reflecting structure - allows to see in dark but with less acuity Found within medium vessel layer of choroid

Question 34

Which layer of the choroid contains capillaries that supply the retina?

Answer 34

Choriocapillaris

Question 35

What is the function of the large vessel layer of the choroid?

Answer 35

Cool the eye | Heat via light