Function Of The Ciliary Body

Question 1

What is not a function of the ciliary body

Answer 1

Contains the minor arterial circle of the iris

-does contain the major circle

Question 2

Order the structures appear on gonioscopy

Answer 2

Schwalbes line
TM
Sclera spur
Ciliary body

Question 3

Are both posterior structures from the iris and the ciliary body pigmented?

Answer 3

No, iris is pigemented on the backside and the ciliary body is nonpigmented on the backside

Question 4

Connected the cornea to the conjunctiva

Answer 4

Schwalbes line

Question 5

Why is the ciliary muscle atypical for smooth muscle

Answer 5

Rapid contraction speed
Large size of motor neurons
Distance between the muscle and the motor neurons
Structure of the ciliary muscle cells resembles skeletal muscle

This is because we are constantly changing accommodation

Question 6

Ciliary muscle in birds

Answer 6

It is skeletal muscle

Question 7

Functions of the ciliary body

Answer 7

• aqueous production
• aqueous outflow
• accommodation

Question 8

What is aqueous production important for

Answer 8

Supplies nutrients to lens and cornea BC they are avascular

Question 9

What is aqueous outflow important for

Answer 9

Maintain IOP

Remove waste products

Question 10

Production and secretion of aqueous humor

Answer 10

1. Diffusion
2. Ultrafiltration
3. Active secretion (80-90% of production)

Question 11

What is the most significant factor in aqueous production

Answer 11

Active secretion

Question 12

What is the purpose of aqueous production

Answer 12

• nutrients to cornea and lens
• ascorbate cxn 20x higher in aqueous than in blood plasma
• free radical that is important to prevent oxidative damage
• low cxn of protein to prevent light scatter
• carries waste products from cornea and lens
• high cxn of lactate in aqueous, metabolic waste product of glycolysis of the lens and cornea

Question 13

Ascorbate in aqueous

Answer 13

20x higher than in the blood

Question 14

What is ascorbate in the aqueous important for

Answer 14

Prevent oxidative damage

Question 15

Protein in the aqueous

Answer 15

Low levels to prevent light scatter

Question 16

Lactate in the aqueous

Answer 16

High cxn of lactate which is a metabolic waste produce of glycolysis of the lens and cornea

Question 17

How much aqueous is produced per minute

Answer 17

2.5 microliter

Question 18

When is aqueous production higher

Answer 18

During the day, decreases 50% at night

Question 19

Blood vessels and aqueous

Answer 19

Dilating and constricting blood vessels can influence aqueous blood vessels by increasing and decrease blood volume

Heh?

Question 20

Size of zonular fibers

Answer 20

70-80nm in diamter

Question 21

What are the zonular fibers

Answer 21

Elastic fibers
Stabilize the lens
Allows fluid to flow from posterior chamber to the vitreous chamber
Superficial attachment to the lens

Question 22

When is acocmmodation completely lost by

Answer 22

Age 50

-some presbyopia read well due to pupil constriction and miosis

Question 23

Tell me about accommodation

Answer 23

Contraction of the longitudinal fibers of the ciliary muscel pulls the choroid forward, the contraction of the circular fibers draws the ciliary body closer to the lens,decreased the diameter of the ring formed by the ciliary body. This releases tension on the zonular fibers and allows the lens capsule to adopt a more spherical shape. The lens thickens, and the anterior surface curvature increases. These changes result in an increase in refractivepower or accommodation

Question 24

What is the lens contained in

Answer 24

An elastic envelope, the lens capsule

Question 25

What is the lens capsule suspended by

Answer 25

Zonular fibers that arise from the dilatory epithelium and attach to the lens equator

Question 26

Zonular fibers in far vision

Answer 26

While far vision is maintained the ciliary muscle is relaxed. Zonular fibers are pulling on the lens capsule

Question 27

What happens to the zonular fibers when the ciliary muscle contracts?

Answer 27

The fibers slacken. The lens adopts a new shape with the anterior surface building forward and the lens becoming thicker with a decreased diamter thereby increasing the power of the lens

Question 28

What does ACh bind

Answer 28

Ciliary muscle receptors (M)

Question 29

Pilocarpine and ciliary muscle

Answer 29

Binds M receptors and can cause contraction

Question 30

Which eyes will be less effected by dilating drops

Answer 30

Pigmented epithelium in the iris and ciliary body bind with this. Dark irides will therefore be less effected by dilating drops

Question 31

Ciliary muscle can be temporarily paralyzed with _____

Answer 31

M antagonists like atropine, cyclopentolate, and tropicamide

Question 32

Measuring accommodation

Answer 32

- rely on perception of clarity - overestimate accommodative response - acocmomdation and convergence stimulate miosis - objective measurements can be obtained from autorefractoe and aberrometer - push up test has an increase in letter size - changes in illumination will after pupil diamter was well

Question 33

What is reduce near vision from

Answer 33

Not a loss of ciliary body muscel function but from a thickened and stiff lens

Question 34

Structural changes in aging eye that can affect accommodation

Answer 34

Thickening of tendons, reduced muscle mass and increase in connective tissue

Question 35

Muscarinic receptors and aging

Answer 35

No cchange at all

Question 36

Loss of the ability to accommodate

Answer 36

Presbyopia | -normal are-related change and the subject of significant research

Question 37

Tendons and presbyopia

Answer 37

The tendon attaches the ciliary muscle to the scleral spur shows extensive age-related structural changes: it thickens with age and becomes surrounded by a dense layer of collagen thus losing its elasticity , restricts muscle movement

Question 38

Ciliary muscel contractive power

Answer 38

Increases up until age that presbyopia manifests - no change in zonular length with age - aging ciliary muscle looks like young when relaxed

Question 39

Ciliary strength and age

Answer 39

Gets stronger as you get older

Question 40

Ciliary muscle contraction and aqueous outflow

Answer 40

Ciliary muscle contraction can change the configuration of the TM BC some of the longitudinal fibers are attached to TM sheets. This altered configuration can facilitate aqueous movement through the anterior chamber angle structures

Question 41

Accommodation and IOP

Answer 41

Reduction

Question 42

Iris sphincter muscle is derived from

Answer 42

Neural ectoderm

Question 43

Ciliary muscle is derived from

Answer 43

Mesoderm

Question 44

If breakdown of blood aqueous nbarrier occurs, cells and flare will be visible

Answer 44

Tyndall phenomenon

Question 45

Factors of Tyndall phenomenon

Answer 45

- leukocyte - usually whitish - can form hypopyon

Question 46

Trauma to head or injury such as whiplash can tear or break the iris. This can break the iris blood vessels entering from the major circle of the iris nad blood settles inferiroly

Answer 46

Hyphema

Question 47

How to locate schwalbes line on gonio

Answer 47

Look where the two lines of light on the cornea come together and that is it