Your baby's skull isn't one large bone, like an adult's. It starts out as separate bones joined by flexible tissue. You'll be able to feel the soft spots between the bones, called fontanels , on the top and back of your newborn's head.
During birth, the softness of the skull bones and the loose connections between them allow the skull to be gently compressed into a bullet-like shape that more easily fits through the birth canal. This is why many newborns have distinctly pointy heads right after they're born.
Within a few days, though, the bones rearrange themselves and the skull goes back to a dome-like shape. The fontanel on the back of the head usually closes by the time your baby is around 4 months old; the one on top typically doesn't close until after your baby's first birthday.
In the first three years of your child's life, the skull grows rapidly as the brain triples in weight and establishes 1, trillion nerve connections. The brain continues to grow in size and weight until your child is about 16, and the skull continues to grow until age Your baby's spine begins as paired blocks of tissue, known as somites, on each side of the developing spinal cord. These blocks will eventually turn into individual spinal bones vertebrae , as well as the rib cage, muscles, and skin.
The first pair of somites appears when you're about 5 weeks pregnant, and over the next two weeks, the number increases to During this time, it's possible to see the somites during an ultrasound exam; they look like a string of beads. By 8 weeks, the somites disappear as they develop into different types of tissue. When you're between 5 and 6 weeks pregnant, your baby sprouts paddle-like buds that will lengthen and grow into arms. By 8 weeks, he's got leg buds that look like flippers.
His arms reach their final proportions by about 14 weeks; his legs take a few weeks longer. At 16 weeks, your baby starts moving his limbs in a coordinated way. Although you may not feel them until around 18 weeks or later, you can see your baby's acrobatics on ultrasound. As your pregnancy progresses, these movements get so pronounced that at times it can feel like your baby is kickboxing! Some research suggests fetal movements help strengthen her bones.
It's important to get enough calcium and phosphorus to ensure that your baby's bones grow strong and healthy. Vitamin D is also essential because it helps your body use calcium efficiently. Phosphorus deficiency is very rare, but you'll need to check and make sure you're getting enough calcium and vitamin D. You need 1, milligrams of calcium a day. Dairy foods like yogurt, hard cheese, and even ice cream are good sources of the mineral — and provide lots of vitamin D and phosphorus as well.
Nondairy food sources include calcium-fortified juice, almond milk, cereal, and bread, as well as salmon, tofu, and leafy greens like kale and bok choy. If you're not getting 1, milligrams of calcium from food and your prenatal supplement, ask your healthcare provider whether you should take calcium as a separate supplement.
Calcium chews are an easy way to boost your intake. The ankle is a bit different from the wrist; it is where the lower leg bones connect to a large bone in the foot called the talus say: TAL-iss. Next to the talus are six other bones. But the main part of the foot is similar to the hand, with five bones. Each toe has three tiny bones, except for your big toe, which has just two. This brings the bone total in both feet and ankles to 52! Most people don't use their toes and feet for grabbing stuff or writing, but they do use them for two very important things: standing and walking.
Without all the bones of the foot working together, it would be impossible to balance properly. The bones in the feet are arranged so the foot is almost flat and a bit wide, to help you stay upright. So the next time you're walking, be sure to look down and thank those toes! Fixed joints are fixed in place and don't move at all. Your skull has some of these joints called sutures, remember? One of these joints is called the parieto-temporal say: par-EYE-ih-toh TEM-puh-rul suture — it's the one that runs along the side of the skull.
Moving joints are the ones that let you ride your bike, eat cereal, and play a video game — the ones that allow you to twist, bend, and move different parts of your body. Some moving joints, like the ones in your spine, move only a little. Other joints move a lot. One of the main types of moving joints is called a hinge joint. Your elbows and knees each have hinge joints, which let you bend and then straighten your arms and legs.
These joints are like the hinges on a door. Just as most doors can only open one way, you can only bend your arms and legs in one direction. You also have many smaller hinge joints in your fingers and toes. Another important type of moving joint is the ball and socket joint.
You can find these joints at your shoulders and hips. They are made up of the round end of one bone fitting into a small cup-like area of another bone. Ball and socket joints allow for lots of movement in every direction. Make sure you've got lots of room, and try swinging your arms all over the place.
Have you ever seen someone put oil on a hinge to make it work easier or stop squeaking? Well, your joints come with their own special fluid called synovial fluid say: SIH-no-vee-ul that helps them move freely.
Bones are held together at the joints by ligaments say: LIH-guh-mints , which are like very strong rubber bands. Protect those skull bones and your brain inside! When you use a skateboard, in-line skates, or a scooter, be sure to add wrist supports and elbow and knee pads. Your bones in these places will thank you if you have a fall! If you play sports like football, soccer, lacrosse, or ice hockey, always wear all the right equipment. And never play on a trampoline. Many kids end up with broken bones from jumping on them.
Broken bones can eventually heal, but it takes a long time and isn't much fun while you wait. Strengthen your skeleton by drinking milk and eating other dairy products like low-fat cheese or frozen yogurt. They all contain calcium, which helps bones harden and become strong. Be active!
Another way to strengthen your bones is through exercise like running, jumping, dancing, and playing sports. Reviewed by: KidsHealth Medical Experts. Larger text size Large text size Regular text size. It's time to look at all your bones — the adult human body has of them! What Are Bones Made Of? Almost every bone in your body is made of the same materials: The outer surface of bone is called the periosteum say: pare-ee-OSS-tee-um.
It's a thin, dense membrane that contains nerves and blood vessels that nourish the bone. The next layer is made up of compact bone. This part is smooth and very hard. It's the part you see when you look at a skeleton.
Within the compact bone are many layers of cancellous say: KAN-sell-us bone, which looks a bit like a sponge. The framework of bones and joints in the human body is both complex and fascinating — just like you. Bones fit together like a massive puzzle, and rely on a variety of muscles to move at joints from the neck and jaw down to the toes.
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