Theme 1 Questions - Embryology

Embryology

On what day does the neural plate form?

Day 17

On what day do the neuropores close?

Ant - day 22,25 Post - day 25,28

What controls neurone differentiation across both axes?

DV axis - Shh, BMP. AP axis - Pax and others

What allows abcission of the apical complex of a neurone after it has migrated?

Downregulation of N-Cadherin. Helps remove the polar complex and also the centrosome/cilia complex involved in signalling.

Which genes and which signalling molecules control neural tube differentiation across the AP axis?

Genes- Pax
molecules- Wnt, FGF, RA

Follow vesiculation, start to finish. (sketch might make it easier)

Prosencephalon → telencephalon and diencephalon → T becomes the cerebrum. D becomes the thalamic stuff and retina.

Mesencephalon → Mesencephalon → midbrain and colliculi.

Rhombencephalon → metencephalon -→ cerebellum and pons
Rhombencephalon → myelencephalon → medulla oblonGATA

Primary vesicles at 3/4wks

secondary vesicles at 5/6wks

Blocked flow of CSF is?
Impaired absorption of CSF is?

blocked - non-communicating hydrocephalus
impaired - communicating hydrocephalus

At what level is a lumbar puncture performed and why?

L3-5. Done here to avoid the spinal cord which ends at about L1 or 2.