Inside your body are 206 bones. Each bone plays a very important role in making all the mechanics of your body function properly. If a bone is broken, all the bones around it can’t perform their duty properly.
Although bones appear very hard, under the surface they are more like sponges, with lots of air. This makes bones very strong, but very light.
You may think of bone as a hard, dense material, but only one type of bone is like this. This dense, hard bone is called cortical bone. Cortical bones are primarily the “structure” bones.
The adult human body has 206 bones in the skeleton. These bones are grown together from about 300 bones at birth!
Bone marrow is a spongy substance that’s found inside large bones like your hips, pelvis, and femur. Bone marrow houses stem cells. Stem cells are responsible for producing many of your body’s most important cells, including blood, brain, heart, and bone cells.
The spine, which runs down the center of the back, allows the body to bend forward, backward, side to side, and rotate to each side. It provides support for the entire upper body (everything above the hips), and also protects the spinal cord.
Adults will end up with only 206 bones, but babies are born with almost 100 moreTrusted Source. It’s not that bones disappear as we grow older. Instead, these tiny bones fuse together to form the larger bones of the skeletal system.
The ribs, which are in your chest, give support for your lungs, heart, and upper body muscles. One of the biggest jobs the ribs have is to protect the heart and lungs, and also the kidneys.
The stapes, a bone in your inner ear, is the smallestTrusted Source of all your bones. This bone is also sometimes called the stirrup because of its Y shape. Together with the anvil and hammer bones, the stapes helps translate sounds you hear into waves your brain can understand.
The skull, which contains the brain and protects it, is made up of different bones which grow together during childhood. It has places for the eyes, and the ears, and only has one moving part - the lower jaw bone, called the mandible.
The femur, which runs from your hip to your knee, is the longest and largest bone in your body. It’s also the strongest. Just think of all the weight that bone handles in a day.
The hands are made up of many different bones which allow a huge variety of movement. In fact, between the hands, wrists, and fingers, there are 54 bones!
Yes, bones can break. But they’re designed to stand up to daily wear and tear. For example, some bones must be able to absorb two to three timesTrusted Source your body weight in force. They must also be resilient. You take 1 to 3 millionTrusted Source steps per year, so bones are built to take the constant use.
The pelvis, which is the bowl-shaped structure that makes up the hips, attaches the legs to the spine. The pelvis supports the spine, which supports the entire upper body. The back of the pelvis is the sacrum, one of the strongest bones in the body. During pregnancy, the ligaments soften and get a little longer, allowing the bones of the pelvis to relax to fit a baby through. The special hormone that causes this to happen is called relaxin!
You have 206 bones in total, and 106Trusted Source of them are in your hands and feet.
The longest bone in the body is called the femur, which connects the pelvis to the knee.
The hyoid bone, which is in your throat, is the only bone that doesn’t connect to a joint. The hyoid is responsible for holding your tongue in place.
The smallest bone in the body is in the middle ear, and is called the stapes, which is latin for stirrup (this bone is shaped like a stirrup). It is only 0.1 to 0.13 inches long!
A 13th rib is rare — only 1 percentTrusted Source of people are born with it. In most people, this extra rib, called a cervical rib, can cause medical issues like neck pain. For that reason, people born with this extra rib often have it removed.
Bones are broken down and remade constantly, just like skin. In fact, all of the bones are slowly replaced until they are new bone once every 7 years!
At the knee joint, three bones connect: your femur, tibia, and patella. Those three large bones require an equally large joint to connect them. That’s why your knee is the largest joint in your body.
The insides of some bones contain special material called bone marrow. Bone marrow has lots of cells which make red blood cells. Red blood cells carry oxygen all over the body. Every second, bone marrow produces two million red blood cells!
Humans are part of a group of creatures called vertebrates. That means our bones are covered by a system of tissue and skin. Only 10 percent of the world’s animals (humans included) are vertebrates.
The best way to look at bones is with a special photo called an X-ray. X-rays help tell doctors where a fracture is located, so they know where to put a cast.
The enamel on your teeth, which are considered part of your skeletal system, is actually stronger than bones. Enamel protects the delicate nerves and tissue inside your teeth. Inch for inch, your teeth can take more wear and tear than any of your other bones.