These abilities are controlled by the brainstem, which sits above the spinal cord but below the higher, more recently-evolved cerebral cortex. It is largely mature by the end of the second trimester, which is when babies first become able to survive outside the womb.
Last of all to mature is the cerebral cortex, which is responsible for most of what we think of as mental life—conscious experience, voluntary actions, thinking, remembering, and feeling. It has only begun to function around the time gestation comes to an end.
Premature babies show very basic electrical activity in the primary sensory regions of the cerebral cortex—those areas that perceive touch, vision, and hearing—as well as in primary motor regions of the cerebral cortex. In spite of these rather sophisticated abilities, babies enter the world with a still-primitive cerebral cortex, and it is the gradual maturation of this complex part of the brain that explains much of their emotional and cognitive maturation in the first few years of life.
How does nutrition affect the developing brain? Which plays a more important role in brain development, nature genes or nurture environment? Are there critical periods in the development of every brain function?
These include:. Within 4 weeks, the rudimentary structure known as the neural plate develops, which Gaither says is considered the precursor to the nervous system. The neural tube continues to grow, but around week 6 or 7, Gaither says it closes, and the cephalad portion aka the rudimentary brain separates into three distinct parts: front brain, midbrain, and hindbrain.
These early connections allow the fetus to make its first movements. During the second trimester , Gaither says the brain begins to take command of bodily functions. This includes specific movements that come from the hindbrain, and more specifically, the cerebellum. One of the first notable developments, sucking and swallowing, are detectable around 16 weeks. Fast-forward to 21 weeks, and Gaither says baby can swallow amniotic fluid. Remember the cerebellum or the part of the brain responsible for motor control?
Gaither points out that a fetus can begin to hear during the late second trimester, and a sleep pattern emerges as the brainwaves from the developing hypothalamus become more mature. By the end of the second trimester, Gaither says the fetal brain looks structurally much like the adult brain with the brain stem almost entirely developed. The third trimester is full of rapid growth.
In fact, as your baby continues to grow, so does the brain. The most notable part of the brain during this final trimester is the cerebellum — hence, the kicking, punching, wiggling, stretching, and all of the other movements your baby is performing. While it may feel like you have control over nothing for the next 9 months, you do have a say in the foods you eat. Healthy brain development starts before pregnancy.
According to the Centers for Disease Control and Prevention , a healthy diet that includes folic acid, both from foods and dietary supplements, can promote a healthy nervous system.
This may include anencephaly or spina bifida. Just four weeks after conception, the neural tube along your baby's back is closing. The baby's brain and spinal cord will develop from the neural tube. The heart and other organs also are starting to form. Structures necessary to the formation of the eyes and ears develop.
Small buds appear that will soon become arms. Your baby's body begins to take on a C-shaped curvature. By the end of the seventh week of pregnancy — five weeks after conception — your baby's brain and face are the focus of development. Seven weeks into your pregnancy, or five weeks after conception, your baby's brain and face are growing.
Depressions that will give rise to nostrils become visible, and the beginnings of the retinas form. Lower limb buds that will become legs appear and the arm buds that sprouted last week now take on the shape of paddles. Eight weeks into your pregnancy, or six weeks after conception, your baby's lower limb buds take on the shape of paddles.
Fingers have begun to form. Small swellings outlining the future shell-shaped parts of your baby's ears develop and the eyes become obvious. The upper lip and nose have formed. The trunk and neck begin to straighten. By the end of the ninth week of pregnancy — seven weeks after conception — your baby's elbows appear. In the ninth week of pregnancy, or seven weeks after conception, your baby's arms grow and elbows appear. Toes are visible and eyelids form.
Your baby's head is large but still has a poorly formed chin. By the end of the 10th week of pregnancy — eight weeks after conception — your baby's toes and fingers lose their webbing and become longer. By the 10th week of pregnancy, or eight weeks after conception, your baby's head has become more round. Your baby can now bend his or her elbows. Toes and fingers lose their webbing and become longer.
The eyelids and external ears continue to develop. The umbilical cord is clearly visible. At the beginning of the 11th week of pregnancy, or the ninth week after conception, your baby's head still makes up about half of its length. However, your baby's body is about to catch up. Your baby is now officially described as a fetus. This week your baby's face is broad, the eyes widely separated, the eyelids fused and the ears low set.
Buds for future teeth appear. Red blood cells are beginning to form in your baby's liver. By the end of this week, your baby's external genitalia will start developing into a penis or a clitoris and labia majora.
Twelve weeks into your pregnancy, or 10 weeks after conception, your baby is sprouting fingernails. Your baby's face now has taken on a more developed profile. His or her intestines are in the abdomen. There is a problem with information submitted for this request. Sign up for free, and stay up-to-date on research advancements, health tips and current health topics, like COVID, plus expert advice on managing your health. Error Email field is required.
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