Human Growth and Development

Fetal Stage (Weeks 9 - Birth): ●​ The longest stage of prenatal development. ●​ Organs continue maturing; most are functional by the 7th month. ●​ By 24 weeks, the fetus is viable, meaning it can survive outside the womb with medical support. ●​ The fetus becomes active and responds to stimuli like sound and touch.

Prenatal Brain Development Brain development begins prenatally, with rapid neurogenesis and neuronal migration in the embryo stage. This process lays the foundation for the intricate neural networks that will underlie all future thoughts, behaviors, and emotions. First Trimester (Months 1–3) ●​ The neural tube (which

becomes the brain and spinal cord) forms around day 25. ●​ By week 8, the embryo begins to resemble a human with a large head. ●​ Reflexes start developing by the end of the trimester. Second Trimester (Months 4–6) ●​ Neural connections strengthen, and reflexes improve (e.g., sucking and swallowing).

●​ By 24 weeks, the brain’s basic structure is fully developed. ●​ The fetus reacts to noise and begins to move more actively. Third Trimester (7-9 months) ●​ Brain growth accelerates, preparing for learning and memory.

●​ The fetus becomes highly responsive to external stimuli like the mother’s voice and touch. ●​ By the 9th month, the fetus has the same number of neurons as an adult, though the brain is only 25% of an adult’s size. Issues During Prenatal Development A mother’s physical and emotional health during pregnancy greatly influences fetal development. Problems that arise during this time can have lasting effects on a child’s health and growth.

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