Embryology

Question 1

Meso and ectoderm general breakdown

Answer 1

Meso:

• muscles (not iris)
• mesenchyme = bone, blood vessels

Ecto:

• surface = corneal epi, lens, tears
• neural = iris muscles, sensory retina, RPE, neural crest cells

Question 2

Optic cup and stalk

Answer 2

Optic cup

• outer -> RPE, PCE, anterior iris epi
• inner -> neural retina, NPCE, posterior pigmented iris epi

Optic stalk
-precursor to optic nerve

Question 3

Formation of lens

Answer 3

From surface ectoderm
Post epi differentiates into primary lens fibers -> embryonic nucleus by 2 mo
All lens growth after development of embryonic nucleus can be attributed to secondary lens fibers
-no posterior lens epi in adults

Question 4

Cornea development

Answer 4

Epi = surface ecto
Rest = neural crest cells

Question 5

Surface ecto

Answer 5

Epi: cornea, conj, lid
Lens
Glands + NLD system (tears)

Question 6

Neural ecto

Answer 6

Retina
ON fibers
Epi: CB, iris
Iris muscles

(Structures that do not change thruout life)

Question 7

Neural crest cells

Answer 7

Cornea (not epi)
Angle: TM, iris and CB stroma
Sclera
Choroid
Vitreous