Bones (Meaning and Explanation)

We explain everything about bones, how they are classified, their function and structure. Also, how many bones does the human body have?

bones human body — Bones are the hardest and most resistant parts of the human body.

What are bones?

The bones are a set of rigid organic structures, mineralized through 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 in the body makes up the skeletal system or skeleton, physical support of the organism. 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 phyla.

Furthermore, within the bones there is bone marrow, which fulfills hematopoietic functions or the creation of red blood cells. That is to say that It is a set of organs with complex functions 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, surely a consequence of the fact that they are the last thing in the human body to decompose after death.

The bones gradually solidify as the individual grows during early childhood, and grow together with it until reaching its final size. Similarly, bones can regenerate their own breaks (fractures) through a process called bone consolidation, and they are in a constant process of remodeling within the body.

Types of bones

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

Long bones As their name indicates, they have a predominant length over width and thickness, and are dense, strong bones, within which the red and yellow marrow are housed.
Short bones These are bones whose three dimensions (length, width and thickness) are practically equal.
Flat bones In these bones, length and width clearly predominate over thickness, since they usually constitute the framework of the different cavities of the body.
Irregular bones This last category includes all bones whose shape prevents them from being classified in any of the previous three.

Bone function

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

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

bone structure

bones structure — Bones are much more than just support structures of the body.

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

medullary cavity The “hollow” region of the bone where the bone marrow is housed, generally located in the diaphysis.
Endosteum It is a thin membrane of connective tissue that lines the inside of the medullary cavity of long bones.
Nutrient artery The artery that supplies blood to the bone through its nutritional foramina and which is then distributed throughout the bone through increasingly thinner capillaries.
bone tissue The main component of bone, made up 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 around 30% collagen.
Periosteum The membrane of tough, fibrous connective tissue that covers the bones in their external region.

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How many bones does the human body have?

The skeletal system of the human body It is made up of 206 different bones articulated in a different way to cartilage, ligaments, muscles and tendons.

bone diseases

bones diseases osteoporosis — Bones become more brittle with osteoporosis.

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

Cancer Bone marrow cancer is produced, like other tumors, by the abnormal multiplication of cells in its soft part (tumors called myelomas), or sometimes between hardened cells in 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 their thinning and increased fragility. It is closely 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 ailment, which causes abnormal functioning of the cells that form bone, causing an abnormal thickening and widening of the skeletal structure, which threatens the patient's health.
Rickets A disease derived from a deficiency of vitamin D in the diet, or also from some endogenous problem that prevents the absorption of said nutrient, essential for bone calcification. For this reason, people suffering from this disease suffer from a progressive weakening of the bones, which thus become painfully fragile and brittle.

Continue with: Musculoskeletal system