19. Developmental Anatomy: Neural Crest, Eye, Ear Flashcards Preview

NSB > 19. Developmental Anatomy: Neural Crest, Eye, Ear > Flashcards

Flashcards in 19. Developmental Anatomy: Neural Crest, Eye, Ear Deck (39)
Loading flashcards...
1

Where do neural crest cells come from?

Lateral edge of neural ectoderm

2

Where do neural crest cells migrate once the neural fold is closed?

Into mesenchyme
Enter mesoderm

3

Which disease is due to the failure of neural crest cells to migrate into the bowel wall?

Hirschsprung's disease

4

Why are there no bowel reflexes in Hirschsprung's disease?

No parasympathetic plexus

5

Which parts of the bowel are most affected by Hirschsprung's?

Sigmoid colon
Rectum

6

What does Hirschsprung's disease present as?

Constipation
Vomiting
Abdominal distension

7

What is the first sign of eye development on day 22?

Pair of shallow grooves at the side of the forebrain

8

What are the outpocketings of forebrain known as?

Optic vesicles

9

What causes the changes needed for lens formation?

Vesicles come in contact with surface ectoderm

10

What is the optic cup formed by?

Invagination of the optic vesicle

11

What are the layers of the optic cup separated by?

Intraretinal space

12

What gap allows the hyaloid artery to reach the inner chamber of the eye?

Choroid fissure

13

What will eventually form the pupil?

Fused lips of the choroid fissure, which form a round opening in the optic cup

14

What forms the lens placode?

Elongated cells of the surface ectoderm

15

What happens at the canal of Schlemm?

Aqueous humour drains into venous circulation

16

What are the retina, iris and optic nerve derived from?

Neuroectoderm

17

What are the lens and corneal epithelium derived from?

Surface ectoderm

18

What does the mesoderm between the neuroectoderm and surface ectoderm form?

Fibrous and vascular coats of the eye

19

What are the choroid, sclera and corneal endothelium derived from?

Neural crest cells

20

What is a coloboma?

Choroid fissure fails to close

21

What are the causes of congenital cataracts?

Genetics
Maternal rubella

22

What is cyclopia?

Fusion of eyes due to loss of midline tissue

23

What is the first sign of ear development?

Thickening of surface ectoderm on each side of rhombencephalon (Otic placodes)

24

What are otic placodes known as once they invaginate?

Otic or auditory vesicles

25

What does each otic vesicle divide into?

Ventral and dorsal parts
Differentiation forms ganglion cells for vestibulocochlear ganglia

26

What is derived from the ventral part of the otic vesicle?

Saccule and Organ of Corti

27

What is derived from the dorsal part of the otic vesicle?

Utricle
Semicircular canals
Endolymphatic duct

28

What is the collective names for the structures formed by the ventral and dorsal vesicles?

Membranous labyrinth

29

What happens to the otic vesicle in the 4th week?

Detaches from surface ectoderm

30

What role do neural crest cells have in the ear?

Form bony labyrinth in temporal bone