Anatomy and Embryology of the Eye Flashcards Preview

Neurology > Anatomy and Embryology of the Eye > Flashcards

Flashcards in Anatomy and Embryology of the Eye Deck (25):
1

Where is the eye derived from embyrologically?

Neural tube

2

How are the optic vesicles formed?

Grow out from diencephalic part of neural tube
Reach surface ectoderm and cells thicken to form lens placode
Lens placode starts to push inwards, optic vesicle to form an optic cup

3

How many layers does the optic cup process?

2 layers

4

What is the choroid fissure?

A hole on the inferior wall of the optic cup through which blood vessels pass

5

What happens to the choroid fissure?

Disappears, can persist to form a gap called a coloboma

6

What does the surface ectoderm go on to form?

Eyelids
Conjunctiva
Corneal epithelium

7

What does the mesenchyme form?

Choroid
Stroma of cornea
Sclera
Extraocular muscles

8

What is a retinal detachment?

Liquified vitreous enters through holes in the peripheral retina into space between outer and inner layers of optic cup

9

What is the function of orbital fat?

Cushions globe
Important for support

10

What type of epithelium is present on the cornea?

Stratified squamous non-keratinised

11

How is the transparency of the cornea maintained?

Regular arrangement of collagen in stroma
No blood vessels
Endothelium pump keeps aqueous humour out

12

What role does avascularity play in corneal transplants?

Lesser chance of foreign antigens from graft being recognised by recipient so less chance of rejection

13

What is the role of the cornea?

Allow light rays to enter eyeball

14

What is the role of the sclera?

Gives attachment to muscles moving the eyeball

15

What is the role of the ciliary body?

Suspends the lens
Produces aqueous humour

16

What is the role of the iris?

Controls diameter of the pupil so controls amount of light rays entering the eye

17

What is the role of the choroid?

Supplies blood to outer layers of retina

18

What os the role of the retina?

Light sensitive rods and cones which enables sight

19

What is a lens opacification commonly known as?

Cataract

20

What is the role of the aqueous humour?

Maintains intraocular pressure

21

What is the role of the vitreous humour?

Cushions the retina

22

What is the role of the trabecular meshwork?

Filters aqueous humour through it

23

Where does the lacrimal gland receive innervation from?

Parasympathetic from facial nerve

24

Where does the duct of the lacrimal gland open?

Conjunctival sac

25

What is the role of a tear film?

Keeps cornea moist
Washes away any foreign bodies
Contains antibodies and lysozymes to kill microbes
Provides smooth surface for refraction