BRAIN DIVISION EMBRYO (MINOR)

Question 1

what are the three primary divisions of the brain?

Answer 1

Proencephalon, Mesencephalon, Rhombencephalon

Question 2

what does the PROENCEPHALON become?

Answer 2

The Pro - is the first swelling seen (rostral)
The Telencephalon (cerebral hemispheres), The Diencephalon (Thalamus, Hypothalamus)

Question 3

what does the MESENCEPHALON become?

Answer 3

The Midbrain

Question 4

what does the RHOMBENCEPHALON become?

Answer 4

Note that the rhombencephalon derivates into 7 vesicles. 
the Metencephalon (pons/cerebellum - thus same embryological derivations)
the Myencephalon (medulla)

Question 5

How is the Neural Tube Folded? What side is first?

Answer 5

The NT is folded rostral to caudal; 5 zippers thus 5 mechanism thus 5 potential signs of dysfunction.

1. The first site is the midback
2. Skull - anencephaly (no formation of brain)
3. Face
4. Back of the head
5. The lower back - spinobifida

Question 6

What are neural crest cells and what are they responsible for?

Answer 6

NCC - are parts of the neuroplate that doesnt become the CNS.
It is responsible for becoming the PNS, Facial structure (bones, cartilage, muscle), melanocytes, Dentine

NCC - the longest path that is travelled is to the enteric nervous system.

Question 7

What is Fragile X Syndrome?

Answer 7

Male Autism - due to a mutation in the FMR1 (FX mental retardation gene) - impacts synapses/dendrites

Question 8

What is the topographic organization of the ventral horn?

Answer 8

Proximal muscles - more medial, Distal muscles - more lateral

Question 9

How is the ventral horn filled with aMN.

Answer 9

NC - releases SonicHedgeHog (SH) –> go to the overlying FLOOR PLATE CELLS –> stimulates them to produce SH –> differentiation of the ventral space –> aMN –> aMN release Motor Neuron Factor –> Interneurons produced dorsal to aMN