What are the bones?

We explain everything about bones, how they are classified, their function and structure. In addition, how many bones the human body has.

1. What are the bones?

Bones are a set of rigid organic structures, mineralized by the accumulation of calcium and other metals . They constitute the hardest and most resistant parts of the human body and other vertebrate animals (only surpassed by tooth enamel).

The set of all the bones of the body makes up the skeletal or skeletal system, the body’s physical support. In the case of vertebrates, this support is found inside the body (endoskeleton), instead of outside (exoskeleton) as in the case of arthropods and other animal edges.

In addition, within the boness is the bone marrow, which fulfills hematopoietic functions or creation of red blood cells. That is to say that it is a set of complex function organs , which have adipose tissue, blood vessels and even nerves inside.

Bones are much more than simple support structures of the body, although we have the opposite idea, probably because they are the last to decompose of the human body after death.

The bones gradually solidify as the individual grows , during early childhood, and they grow along with him until he reaches his final size. Similarly, boness can regenerate their own breaks (fractures) through a process called bone consolidation, and they are constantly remodeling within the body.

2. Types of bones

Depending on their shape and appearance, the boness of the human body can be classified into four categories, which are:

• Long bones . As the name implies, they have a predominant length to width and thickness, and are dense, strong bones, within which the red and yellow marrow is housed.
• Short bones . These are the bones whose three dimensions (length, width and thickness) are practically the same.
• Flat bones . In these boness the length and the width predominantly over the thickness, since they usually constitute the frame of the different cavities of the body.
• Irregular bones . In this last category, all the boness whose shape prevents them from being classified in any of the previous three enter.

3. Bone function

Bones fulfill various functions in the body, which can be summarized in:

• They provide structural support to the body, retain their shape and protect the internal organs outside.
• The bone marrow produces red blood cells that carry oxygen transport in the blood.
• Together with the muscles, joints, ligaments and tendons, the bones allow voluntary movement of the body.
• Bones are an important region of storage of resources , not only calcium and phosphorus, necessary for their hardening, but also certain types of lipids and last minute use resources.

4. Bone structure

Bones are made up of three parts, called diaphysis (central portion of the body of the bone), epiphysis (ends of long bones) and metaphysis (intermediate portion of the bone). Similarly, from the inside out, they are composed of:

• Medullary cavity . The “hollow” region of the bone where the bone marrow is located, usually located in the diaphysis.
• Endostio . It is a thin membrane of connective tissue that covers the inside of the medullary cavity of the long bones.
• Nutricia artery . The artery that supplies blood to the bone, through its nutritional holes and then distributed through the bone through increasingly thin capillaries.
• Bone tissue . The main component of bone, consisting of bone cells (osteocytes, osteoblasts, osteoclasts and stem cells) in 2% of the tissue, and 70% of resistant extracellular substance (hydroxyapatite) secreted by them, from calcium and phosphorus, in addition to about 30% collagen.
• Periosteum . The membrane of fibrous and resistant connective tissue that covers the bones in its outer region.

5. How many bones has the human body?

The bone system of the human body is composed of 206 different bones , articulated in different ways to the cartilage, ligaments, muscles and tendons.

6. Bone diseases

Like other parts of the body, the bones can suffer injuries (fractures, trauma) or they can be victims of diseases. The best known of these are:

• Cancer . Bone marrow cancer is caused, like other tumors, by the abnormal multiplication of the cells of its soft part (tumors called myelomas), or sometimes between hardened cells of its rigid part (called sarcomas). It leads to weakening of the structure and painful local numbness.
• Osteoporosis . This disease consists of a chronic loss of calcium in the bones, causing them to thin and increase their fragility. It is very associated with advanced age and other processes of the body, so it requires a combined treatment, through calcium supplements and physical exercise.
• Paget’s disease . This is the name of a congenital condition, which causes abnormal functioning of the cells that originate the bone, causing abnormal thickening and widening of the skeletal structure, which threatens the patient’s health.
• Rickets . A disease derived from the deficiency of vitamin D in the diet , or also of some endogenous problem that prevents the absorption of said nutrient, essential for the calcification of the bones. That is why people afflicted with this disease suffer from a progressive weakening of the bones, which thus becomes painfully fragile and brittle.