A 2D scientific schematic illustrating human brain development with four stages from 2nd trimester to 1 year after birth.

A clean 2D scientific schematic of human brain development timeline. Four stages displayed from left to right: 1) 2nd trimester fetus brain – completely smooth cortex. 2) 3rd trimester fetus brain – beginning of cortical folding with emerging sulci and gyri. 3) At birth – clearly folded brain with main sulci visible. 4) 1 year after birth – fully folded, mature cortex. Each stage represented with a simplified 3D silhouette of the brain, showing progressively more complex folds. Timeline below with labeled milestones: "2nd trimester", "3rd trimester", "Birth", "1 year". Soft scientific color palette: white background, light blues, grays, and subtle shadows, professional and minimalistic, no text inside the brain shapes. See more