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Human Brain Development During development, there are huge bodily changes taking place every second. In particular, the brain grows at an amazing rate. While in the womb, a fetus' brain may have up to 250,000 neurons added every minute. In the table below you will see pictures of fetus brains at different stages of development. Note that the last picture, at 36 weeks, represents the fetus' brain at birth. Notice the drastic differences between the brain at 22 weeks and at 36 weeks! 22 weeks 23 weeks (mid-sagittal section) 27 weeks 32 weeks (mid-sagittal section) 36 weeks (images thanks to Univ. of Utah Medical School site) You may note that by 36 weeks, there are apparent sulci and gyri (the convolutions seen on the cortical surface), the brain has increased in size, and various structures become more distinct and apparent. Compare the fetus brain pictures above with the following picture of an adult brain: (image thanks to Comparative Mammalian Brain Collections) The fetus brain at 36 weeks and the adult human brain look the same to me. What's the big deal?! HOME || VARIATION || PATHOLOGY || GENDER & SEXUAL ORIENTATION || BIBLIOGRAPHY