Development

Question 1

treacher collins and Di George syndromes are due to what?

Answer 1

Migratory failure of neural crest cells

Question 2

What causes the induction of the neural tube?

Answer 2

Inhibition of BMP4

Question 3

What effect do Chordin and Noggin have on neural tube development?

Answer 3

Inhibit BMP4, inducing the neural tube

Question 4

What switch causes the neural tube to fuse?

Answer 4

Change of E-cadherin to N-cadherin

Question 5

What do the neural crest cells give rise to?

Answer 5

"MOTEL PASS DC":
M- melanocytes 
O- odontoblasts
T- tracheal cartilage
E- enterochromaffin cells
L- layngeal cartilage
P- pseudounipolar cells
A- All ganglia / Adrenal medulla
S- schwann cells
S- spiral membrane
D- Dorsal root ganglia
C- parafollicar C cells of thyroid

Question 6

When do the anterior and posterior neuropores close?

Answer 6

Anterior - day 25

Posterior - Day 27

Question 7

What do the alar and basal plates of the mantle layer (of neuroblasts) develop into?

Answer 7

Grey matter:
Alar plate - Dorsal sensory horn
Basal plate - Ventral motor horn

Question 8

From what does the white matter arise?

Answer 8

Marginal layer (outer layer) of neuroblasts - nerve fibres emerge from neuroblasts and myelinate, forming white matter

Question 9

Describe the process of brain development

Answer 9

Prosencephalon - telencephalon - cerebum

Prosencephalon - diencephalon - thalamus, hypothalamus and epithalamus

Mesencephalon - midbrain

Rhobencephalon - metencephalon - Pons and cerebellum

Rhombencephalon - Myelencephalon - Medulla oblongata

Question 10

What happens if anterior neuropore fails to close?

Answer 10

Anencephaly - absence of brain, skull and scalp

Question 11

What happens if posterior neuropore fails to close?

Answer 11

Spina Bifida

Question 12

Where do the meninges develop from?

Answer 12

Mesenchymal and neural crest cells - all from mesoerm

Question 13

What happens to CSF in spina bifida?

Answer 13

builds up due to cerebellum obstructing foramen magnum, causing hydrocephalus

Question 14

Zika virus, viral infections in pregnancy, chromosomal abnormalities and craniosynostosis can all individually cause what?

Answer 14

Microcephaly

Question 15

Describe the process of eye development

Answer 15

Look in book

Question 16

What is the key regulatory molecule in eye development?

Answer 16

PAX6

Question 17

What role does SHH play in eye development

Answer 17

Responsible for eye field separation by upregulating PAX2

Ensures PAX 6 is restricted to optic cup and lens

Question 18

A SHH mutation will have what effect on the eye?

Answer 18

Cyclopia