[Verse 1]
Week three, the embryo folds — gastrulation draws the map,
Notochord descends the midline, signals travel up and back,
Neural induction fires the plate, ectoderm begins to bow,
A groove is carved along the axis, neural folds rise now,
By day twenty-five the anterior neuropore seals shut,
Two days later, posterior closes — miss that window and it cuts:
Anencephaly where the front fails, myelomeningocele below,
Encephalocele where the vault cracks and the tissue starts to show
[Chorus]
Three vesicles become five — prosencephalon divides,
Telencephalon, diencephalon, the cortex where thought resides,
Rhombencephalon splits to meta and myelen — hold that line,
Each ventricle maps its vesicle, Monro marks the interventricular shrine,
Cephalic flexure, pontine, cervical — the brainstem bends in three,
Fold it right or face the consequence of failed geometry
[Verse 2]
Secondary neurulation — the caudal cell mass forms by condensing,
Conus medullaris, filum terminale, tethered cord commencing,
No open defect marks the skin but imaging tells the tale,
Occult dysraphism lurks beneath — a lipoma on the trail,
Neural crest cells emigrate — they scatter wide and settle deep,
Dorsal root ganglia, Schwann cells, leptomeninges they keep,
Skull base contributions, autonomic chains in rows,
Neurocristopathy — neurofibromatosis, that's how the story goes
[Chorus]
Three vesicles become five — prosencephalon divides,
Telencephalon, diencephalon, the cortex where thought resides,
Rhombencephalon splits to meta and myelen — hold that line,
Each ventricle maps its vesicle, Monro marks the interventricular shrine,
Cephalic flexure, pontine, cervical — the brainstem bends in three,
Fold it right or face the consequence of failed geometry
[Verse 3]
Prosencephalon fails to cleave — alobar holoprosencephaly,
One monoventricle, fused thalami, no interhemispheric boundary,
Semilobar, lobar — partial failures, still malformed midline seams,
Septo-optic dysplasia — optic nerves thin as torn-apart dreams,
Radial glia scaffold the cortex, neurons climb the lattice slow,
Lissencephaly — the gyrification never gets to flow,
Heterotopia, polymicrogyria — neurons stall or crowd the wall,
Taylor's focal cortical dysplasia, type two-b, seizures call
[Bridge]
Corpus callosum grows front to back — except the rostrum forms last,
Agenesis leaves colpocephaly, parallel ventricles broadcast,
Myelination starts in the brainstem, spreads posterior then to front,
On infant MRI — T1 then T2 flip, read the sequence or you're blunt,
Rathke's pouch climbs from the pharynx, neural downgrowth meets it there,
Adenohypophysis greets the infundibulum — a handshake in mid-air,
Cleft cyst, craniopharyngioma, ectopic posterior gland —
Membranous vault above, endochondral base — sutures command