Bones and the Human Skeleton
The bones of the human body comprise the skeletal system. The skeletal system supports the body. Bones are made of living tissues, making them flexible as well as strong. An adult human has 206 bones, while babies are born with 300 bones; throughout childhood, some bones fuse together as the body grows. Healthy and strong bones are vital for good health. People can take care of their skeletal systems by eating a diet rich in protein, vitamins, and minerals. Regular exercise is also crucial for strong bones.
The Skeletal System
The skeletal system includes bones, tendons, ligaments, and cartilage. Every bone in the skeletal system has an important function. Some bones surround fragile organs in the body, providing protection. For example, the ribs protect the heart and lungs, while the skull protects the brain. Other bones, such as the ones in the arms and legs, enable movement by supporting muscles.
Bones are comprised of both living and non-living tissues. Approximately 70 percent of bones’ content is minerals such as calcium. The hard and smooth outer layer of bones is called the cortical bone. The next layer is the concellous bone, which is porous and spongy in nature. The concellous bone makes it easier to move because it is lighter in weight and slightly flexible. Blood vessels sit within this layer as well. Bone marrow is the substance that sits at the center of bones.
Yellow bone marrow is comprised of fat cells. Red bone marrow produces bone marrow stem cells, which help produce blood cells. Approximately 5 billion red blood cells are produced every day, and these blood cells are responsible for oxygenating all of the tissues in the human body. White blood cells fight off infections to keep the body healthy. And platelets are necessary for clotting to stop bleeding.
Joints are the connection points between bones, tendons, and ligaments. Joints enable movement and provide stability. The body has different types of joints to allow the movement needed. Ball-and-socket joints are present in the hips and shoulders, enabling these bones to rotate and move in all directions. Hinge joints are present in the knees, elbows, fingers, and toes. These joints allow bending and straightening only. Pivot joints are present in the neck, and they allow some rotating movements. Ellipsoidal joints in the wrists allow various movements with the exception of pivoting movements. Cartilage is present in joints to prevent bones from rubbing against each other.
Diagnosing Broken Bones
An X-ray is a common diagnostic test that involves capturing an image of an injury site. Physicians often begin the diagnostic process for a possible broken bone with an X-ray. A technician positions the body part between the X-ray machine and the digital X-ray sensor or film, and then the machine sends electromagnetic waves through the body. X-rays capture images of dense matter because it absorbs radiation. Soft tissues allow radiation to pass through, so these areas appear dark on an X-ray. If a fracture is present in a bone, it will appear darker on the X-ray. X-rays may not show enough detail in some cases, and in these situations, a physician may order a computed tomography scan, commonly known as a CT scan. This diagnostic tool uses X-rays and advanced computer technology to create a cross-section image of the body.
Broken Bones: The Healing Process
When a fracture occurs in a bone, the bones will heal naturally. However, to ensure that the bones heal correctly, physicians immobilize the bones in a sling or cast during the healing process. Bones heal in stages, beginning with blood collecting around the fracture site. Collagen begins to form around the break, providing strength and filling in the gap between the two sides of the broken bone. Eventually, the collagen hardens fully and the bone is healed. The entire healing process takes weeks or even months, and during this time, it’s important to prevent stress on the healing bone.
Interesting Facts About Bones
The smallest bones in the body are located in the ear. Meanwhile, the spine contains 33 separate bones. Bones grow until about age 20, but bones continue to renew themselves throughout life with new bone cells. Calcium is crucial for maintaining strong bone density: If the body is calcium-deficient, bones will become weaker because the body will take calcium from them.
- Skeletal System
- Your Bones
- Overview of the Skeletal System
- Normal Structure and Function of the Musculoskeletal System
- Introduction to Bone Biology: All About Our Bones
- What Are Bones Made of? (PDF)
- Fun Facts About Bones and Joints
- Bone Marrow
- What Is Bone Marrow?
- Joint Anatomy
- The Anatomy of a Joint
- Bone X-Ray
- X-Rays, CT Scans, and MRIs
- X-Rays of the Extremities
- Biology of Fracture Healing
- How Bones Heal
- Healing Bone Fractures: Your Body’s Do-it-Yourself Remodeling Process
- How Does a Broken Bone Heal?
- Fast Facts About Bone Health
- 25 Facts About Your Bones and Osteoporosis (PDF)