Your brain starts forming very early but it doesn’t look much like a brain to start, it looks like a plate. In the womb, when you’ve gone from a ball of cells to something that looks more like a tiny hot dog, the “neural plate” appears.

This flat structure starts to fold and you then end up looking like a hot dog with a V-shape cut into it. That V then connects at the outer surface and forms a hollow tube called the “neural tube”. At one end of the tube (your future head) the cells that make the brain start dividing like crazy making cell types called neurons and glia. Over time, three different regions of the brain start to take shape:

the forebrain, midbrain, and hindbrain.

There is still a lot to learn about how the brain forms! For example, how do the cells know which regions to make? How do the regions know when to stop growing? How are the connections between neurons initially created? Luckily there are many scientists interested in answering these questions!

Our brain starts out as layers of cells (cells are the basic biological unit of life).

As this layer becomes thicker and flatter, it forms a plate that then bends and forms a tube that we call the neural tube. Around four weeks of development, this tube closes, and the lower part of the tube then forms the spinal chord as the upper part of the tube starts flex and grow to form the brain - all three parts including the forebrain, the midbrain, and the hindbrain.

These three parts then further divide into 5 parts, where the forebrain divides into 2 and the hindbrain divides into 2 and the midbrain stays as a single part. The forebrain contains what we typically see when we imagine a brain - the two halves. The midbrain is much smaller and tucked "under" the forebrain, while the hindbrain is everything else, including the part that connects the midbrain and forebrain to the spine.

Your brain forms one cell at a time. The cells divide and divide and change.

The brain starts forming after 5 weeks. At 6-7 weeks, the brain forms into 5 different areas. The brain keeps on growing and changing, especially during weeks 27-30.

Your brain forms in the same way as every other organ in your body, by cells dividing at different rates to produce organs of a certain shape and function.