10 Surprising Facts About the Skeletal System

The skeletal system of an adult is made up of 206 bones, 32 teeth, and a network of other structures that link the bones. This system is responsible for giving the body its shape, assisting with bodily movements, and generating new blood cells, among other things.

Here are 10 fascinating things about the human skeleton.

Adults have fewer bones than infants.

Adults have 206 bones in their bodies, but babies do not.

A newborn baby's skeleton is made up of approximately 300 different parts, which are a combination of bones and cartilage. The cartilage gradually solidifies into bone, a process known as ossification; for example, newborns' kneecaps begin as cartilage and solidify into bone after a few years.

Infants' "extra" bones combine to form larger bones over time, decreasing the total number of bones to 206 by adulthood.

Over half of the bones in the body are found in the hands and feet.

Bones come in a variety of shapes and sizes, and their distribution across the body is uneven; some places have much more bones than others. Your hands and feet come out on top.

Every hand has 27 bones, and each foot has 26, for a total of 106 bones in the body's two hands and two feet. That is, your hands and feet hold more than half of your body's bones.

An extra rib can cause health problems in some people.

The average adult has 24 ribs (12 pairs), but one in every 500 people has a cervical rib, which is an extra rib. This rib, which stretches from the base of the neck to just above the collarbone, isn't always completely developed — it can be as thin as a string of tissue fibers.

If the extra rib squashes surrounding blood vessels or nerves, it may cause health problems regardless of its shape. This causes thoracic outlet syndrome, which is characterized by pain in the shoulder or spine, loss of limb sensation, blood clots, and other issues.

With one exception, every bone is linked to another bone.

Between the chin and the thyroid cartilage is the hyoid, a horseshoe-shaped bone in the throat. It's also the only bone in the human body that isn't attached to another.

Because of its position, the hyoid is also considered the anatomical base of speech; it may function with the larynx (voice box) and tongue to create the full range of human vocalizations. The only other group of hyoids like humans is Neanderthals, and the existence of hyoids in those hominids has led scientists to speculate that Neanderthals had complex speech patterns similar to modern humans.

The world's first usable prosthetic bone was created by ancient Egyptians.

Artificial devices that replace missing or wounded body parts are known as prostheses. Some prosthetic body pieces, such as artificial eyes, are purely aesthetic, but prostheses that replace bones, such as prosthetic limbs or joints, serve a practical purpose.

Ancient Egyptians invented the first practical prosthesis, an artificial big toe, around 3,000 years ago. Researchers discovered in 2011 that Egyptians with artificial toes would have had a much easier time walking in sandals than those who were missing their big toes but did not obtain prostheses.

Bone tumors have been a problem for humans for over 120,000 years.

Bones are made up of living, active cells. Bone cells, like all other cells in your body, are vulnerable to benign tumors and even cancer. But this isn't a new problem: tumors have plagued modern humans and their ancestors for thousands of years.

A tumor was discovered in a Neanderthal rib bone dating back 120,000 to 130,000 years in 2013. It's the world's oldest identified human tumor.

Internally bony skeletons are uncommon in animals.

In humans, the bony skeletal structure is concealed under layers of skin and muscle. Other vertebrates, or creatures with backbones, such as amphibians, birds, reptiles, and fish, are in the same boat. However, vertebrates make up just 2% of all animal species on the planet; the remaining 98 percent are invertebrates, such as insects, arachnids, and mollusks.

This suggests that the vast majority of animal species on the planet do not have a bone-based internal or external skeleton. Some invertebrates, such as jellyfish and worms, have exoskeletons composed of a fibrous material called chitin, whereas others, such as jellyfish and worms, have a fluid-filled skeletal structure.

Sharks lose thousands of teeth over the course of their lives.

Teeth are not known to be bones, but they are part of the skeletal system. In a lifetime, most people have 52 teeth: 20 "baby" teeth that fall out during infancy and 32 permanent teeth that emerge later.

Sharks, on the other hand, have serrated front teeth and several rows of replacement teeth that advance as the front teeth fall out. According to the Marine Education Society of Australasia, which aims to enhance people's knowledge of marine ecosystems, teeth are replaced as often as once every 8 to 10 days. Because of the high rate of substitution, some sharks become extinct.

Bones aren't the toughest materials in the body.

Bones are solid, rigid, and built to withstand a lot of force — they are stronger than steel pound for pound. They are, however, not the toughest material in the body.

The title belongs to a different part of the skeleton: tooth enamel. According to the National Institutes of Health, this material protects the crown of teeth and owes its strength to its high concentration of minerals (calcium salts in particular).

Humans have no clear power of their bones.

The walking skeleton is a favorite in Halloween costumes and horror films. Of course, since it lacks a brain or nervous system to guide its movements, such a creature is pure fantasy. And if it had all of these essential elements, the zombie beast would be unable to move.

People move their arms, legs, and other body parts not because they tell their bones to move, but because they tell their muscles to move, which are connected to their bones.

Related:  Fun Facts About Bones and Joints