Lecture 14: Eye Development Flashcards

1
Q

When is the critical period for fetal eye development?

A

Weeks 4-8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What embryonic layers give rise to the eye?

A

Neuroectoderm

Surface ectoderm

Mesoderm/Neural Crest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What part of the brain does the eye originate from?

A

Diencephalon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What do the rims of the optic cup give rise to?

A

Iris and ciliary body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What muscles are the only muscles in the body to arise from neuroectoderm?

A

Dilator and Constrictor pupillae muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What embryonic layer gives rise to the stroma of the iris?

A

Neural Crest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What embryonic layer gives rise to the epithelium of the iris and the ciliary body?

A

Neuroectoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What embryonic layer gives rise to the smooth muscle cells of the ciliary body?

A

Mesoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What congenital disorders can predispose a patient to having separation of the pigmented and neural retina?

A

Down’s syndrome

Marfan’s syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Redevelopment of the intraretinal space comes from separation of what layers?

A

Neural retina (inner layer) and pigmented retina (outer layer)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is aniridia?

What can cause it?

A

Lack of iris tissue

  • Defects in the Pax6 gene
  • Glaucoma, cataracts, other eye abnormalities
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Arrested development of what optic structure during the 8th week can result in aniridia?

A

Rim of optic cup

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What embryonic layer gives rise to the lens of the eye?

A

Surface ectoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What structures of the lens are responsible for its transparent nature?

A

Primary lens fibers - columnar epithelium with dissociated nuclei

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What optic structure do cataracts affect?

A

Lens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Maternal rubella infection between 4-7 weeks gestation can have what effect on fetal eye development?

A

Congenital cataracts (vulnerable lens development)

Congenital glaucoma

Also can be caused by genetics, rubella virus, radiation, and enzyme deficiency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

A 3 week old patient presents with congenital cataracts. He is being breastfed. What is the most likely diagnosis?

A

Congenital Galactosemia

-Accumulation of galactose from milk because of enzyme deficiency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What layer of meninges is the sclera continuous with?

A

Dura

19
Q

What layers of meninges is the choroid continuous with?

A

Pia and arachnoid

20
Q

What optic structure does the pupillary membrane arise from?

A

Sclera

21
Q

When happens to the pupillary membrane?

A

Degenerates at Week 26

22
Q

What secretes the aqueous humor in the posterior chamber?

A

Ciliary Epithelium

23
Q

What is the embryonic origin of primary vitreous humor?

A

Choroid (mesenchyme/NCC)

24
Q

What makes the aqueous humor?

A

Ciliary Body

25
Q

Abnormal neural crest migration to form the scleral venous sinus results in an inability to drain what ocular fluid?

A

Aqueous humor

26
Q

Defects in what gene can cause congenital glaucoma?

A

CYP1B1

27
Q

Elevated intraocular pressure can place patients at risk for what disorder?

A

Congenital Glaucoma

28
Q

What is the embryonic origin of the extra-ocular muscles?

A

Prechordal mesenchyme

29
Q

What embryonic artery gives rise to the Central Retinal Artery?

A

Proximal portion of the Hyaloid Artery

30
Q

What does the Hyaloid A. supply during fetal eye development?

A

Inner layer of optic cup

Lens vesicle

Optic cup mesenchyme

31
Q

What embryonic layer gives rise to the blood vessels of the eye?

A

Mesoderm

32
Q

What embryonic arteries do the ciliary arteries give rise to?

A

Choroidal vessels

33
Q

When do the choroidal vessels develop during fetal eye development?

A

15th week

34
Q

What nourishes the eye when the choroidal vessels degenerate?

A

Aqueous humor

35
Q

A patient presents to the ophthalmologist for a checkup. On examination, the patient’s left eye is smaller than usual and has a worm-like structure on the inside?

What is the most likely cause of this?

A

Persistence of the distal portion of the Hyaloid A.

36
Q

What is the optic stalk’s relationship to the optic nerve?

A

Provides the template and pathway for optic nerve

DOES NOT BECOME OPTIC NERVE

37
Q

What becomes the optic nerve?

A

Neurons of Ganglion Cells

38
Q

What space will papilledema collect in?

Why does this happen?

A

Subarachnoid space of the meninges covering the optic vessels

Increased intracranial pressure slows venous return from retina

39
Q

A patient presents with a key-lock appearing pupil. What is their most likely diagnosis?

A

Coloboma

40
Q

What is the embryological cause of coloboma?

A

Optic fissure fails to close completely, leaving a gap in the iris

41
Q

What is the genetic inheritance of coloboma?

A

Autosomal dominant

42
Q

What does the neuroectoderm give rise to in the eye?

A

Forebrain

  • Retina
    • Neural retina (inner layer)
    • Pigmented retina (outer layer)
  • Iris
    • Pupillae Muscles
    • Epithelium
  • Epithelium Ciliary Body
  • Optic Nerve
43
Q

What does the Surface Ectoderm give rise to?

A

Head

  • Lens of Eye
  • Corneal Epithelium
44
Q

What does the mesenchyme give rise to in the eye?

A

Between surface and neuroectoderm

  • Sclera
  • Stroma of Cornea
  • Choroid (mostly NCC)
  • Stroma of Iris
  • Stroma of Ciliary Muscle