eye and ear devt

Question 1

One structure triggers the formation of another

Answer 1

serial induction

Question 2

serial induction in eye development
Diencephalon outgrowth forms the _________
_________ induces _____________ from ectoderm.
__________ invaginates to form the ________
__________ separates from the surface ectoderm.
_________ thins and becomes transparent.
Eyelid folds develop from ____________.

Answer 2

optic vesicle
lens placode formation
Optic vesicle
optic cup
Lens vesicle
cornea
surrounding mesenchyme

Question 3

retina
outer layer
inner layer

Answer 3

Outer layer: Faces pigmented epithelium.
Inner layer: Faces vitreous humor.

Question 4

photoreceptor
__________ (photosensitive) are located at the top.
__________ cells (horizontal, amacrine, bipolar) connect to _________.
_________ cells form the __________.
Light received by rods and cones triggers a signal cascade through intermediary cells to the optic nerve.

Answer 4

Rods and cones
Intermediary
photoreceptors
Ganglion
optic nerve

Question 5

lens
Lens fibers differentiate in the __________
Anterior region contains _________.
Lens vesicle differentiates into_________ and ________- areas.
Anterior part pushes cells towards the equator for _______________ formation.
Posterior cells become glassy and secrete __________.
Lens focuses light onto the ______________

Answer 5

posterior region.
cuboidal cells
anterior and posterior
lens fiber
crystallin proteins
retina

Question 6

genetics
crucial for eye formation

Answer 6

Pax-6 gene

Question 7

genetics
enables Pax-6 expression to split the eye field into two
This determines the location of the eyes.

Answer 7

Shh gene