6.5.3 Embryology of Eye and Ear Flashcards
What transcription factor aids in distinguishing the eye fields?
PAX6
Identify the embryonic origin of these structures in the middle ear:
Tubotympanic recess
Malleus and Incus
Stapes
Tubotympanic recess: 1st BP
Malleus and Incus: 1st BA
Stapes: 2nd BA
Blockage of the canal of Schlemm at birth leading to increased IOP
What acts as the source of hair cell receptors?
Organ of Corti
Identify the embryonic orgin of these eye structures:
Sclera
Choroid
Eyelids
Cornea
Iris
Dilator and spincter pupillae muscles
Sclera: mesenchyme
Choroid: mesenchyme
Eyelids: surface ectoderm
Cornea: surface ectoderm
Iris: Ectoderm
Dilator and sphincter pupillae muscles: neuroectoderm
What are the three embryonic sources of tissue in eye development?
Surface ectoderm, neuroectoderm, mesenchyme (w/ some neural crest)
The master gene for eye development
PAX6
How do the semicircular canals and crista ampullares, maculae urticuli, maculae sacculi form?
What are the three layers of the eye and their components?
External layer: sclera + cornea
Middle vascular layer: choroid, ciliary body and iris
Inner layer: retina
What are the six structures that migrate, fuse, and progressively develop into the auricle and pinna?
Auricular hilocks
How does the cochlear duct come to be surrounded by the perilymphatic space?
What are the steps in lens development?
Lens placode -> lens vesicle -> growth of lens fibers -> adult lens structure (crystalline gene expression and extrusion of organelles)
What is the clinical result of failed maturation of the lens leading to clouding?
What are the 3 compartments of the eye and their boundaries?
Anterior compartment, posterior chamber, vitreous space
What is the embryonic source of the three parts of the ear?
External ear: 1st and 2nd BA
Middle ear: 1st BP and 1st and 2nd BA
Inner ear: otic vesicle (from surface ectoderm in region of hindbrain)
Describe the early process that the optic groove undergoes to form the optic vesicle. What does the optic vesicle go on to form?
See slide
Optic vesicle goes on to form the the optic cup
What condition results from the failure of the choroidal fissure to close?
Coloboma
What condition results when the embryological structure that intially separates the anterior and posterior chamber fails to degenerate?
Persistance of the iridopupillary membrane
What are the two labyrinths involved in the ear?
What are the two portions of the otic vesicle? What do they go on to form?
Utricular portion: utricle, semicircular canals, endolymphatic duct and sac
Saccular portion: saccule and cochlear duct
What is the name of the groove on the ventral surface of the optic stalk? What type of vessels are contained within the optic stalk?
Choroid fissure; Hyaloid Vessels
What genes have been indicated in the pathology of anopthalmia and microphthalmia?
SOX2 and PAX6
