What is the composition of a human bone, their name in certain parts of the skeleton and other information you will learn from the materials of the presented article. In addition, we will tell you how they are connected to each other and what function they perform.
General information
The presented organ of the human body consists of several tissues. The most important of these is bone. So, let's look at the composition of human bones and their physical properties together.
Bone tissue consists of two main chemicals: organic (ossein) - about 1/3 and inorganic (calcium s alts, lime phosphate) - about 2/3. If such an organ is subjected to the action of a solution of acids (for example, nitric, hydrochloric, etc.), then the lime s alts will quickly dissolve, and the ossein will remain. It will also retain the shape of the bone. However, it will become more elastic and softer.
If the bone is burned well, organic substances will burn, while inorganic substances, on the contrary, will remain. They will maintain the shape of the skeleton and its hardness. Although at the same time human bones (the photo is presented in this article)become very brittle. Scientists have proven that the elasticity of this organ depends on the ossein contained in it, and the hardness and elasticity depend on mineral s alts.
Features of human bones
The combination of organic and inorganic substances makes the human bone unusually strong and resilient. Their age-related changes are quite convincing of this. After all, young children have much more ossein than adults. In this regard, their bones are particularly flexible, and therefore rarely break. As for old people, their ratio of inorganic and organic substances changes in favor of the former. That is why the bone of an elderly person becomes more fragile and less elastic. As a result, old people have a lot of fractures even with minor injuries.
Human bone anatomy
The structural unit of an organ that is visible at low magnification under a microscope or through a magnifying glass is the osteon. This is a kind of system of bone plates located concentrically around the central channel through which nerves and blood vessels pass.
It should be especially noted that the osteons are not closely adjacent to each other. Between them there are gaps that are filled with bone interstitial plates. In this case, the osteons are not arranged randomly. They fully correspond to the functional load. So, in tubular bones, osteons are parallel to the length of the bone, in spongy bones, they are perpendicular to the vertical axis. And in flat ones (for example, in the skull) - parallel or radial to itsurface.
What layers do human bones have?
Osteons together with interstitial plates form the main middle layer of bone tissue. From the inside, it is completely covered by the inner layer of bone plates, and from the outside - by the surrounding ones. It should be noted that the entire last layer is permeated with blood vessels that come from the periosteum through special channels. By the way, larger elements of the skeleton, visible to the naked eye on an x-ray or on a cut, also consist of osteons.
So, let's look at the physical properties of all bone layers:
- The first layer is strong bone tissue.
- The second is a connective that covers the outside of the bone.
- The third layer is a loose connective tissue that serves as a kind of "clothing" for the blood vessels that fit the bone.
- The fourth is the cartilage that covers the ends of bones. It is in this place that these organs increase their growth.
- The fifth layer consists of nerve endings. In the event of a malfunction of this element, the receptors give a kind of signal to the brain.
The human bone, or rather its entire internal space, is filled with bone marrow (red and yellow). Red is directly related to bone formation and hematopoiesis. As you know, it is completely permeated with vessels and nerves that nourish not only itself, but also all the internal layers of the represented organ. Yellow bone marrow promotes skeletal growth and strengthening.
What are the shapes of bones?
Depending on location and functionsthey can be:
- Long or tubular. Such elements have a middle cylindrical part with a cavity inside and two wide ends, which are covered with a thick layer of cartilage (for example, human leg bones).
- Wide. These are the thoracic and pelvic bones, as well as the bones of the skull.
- Short. Such elements are characterized by irregular, multifaceted and rounded shapes (for example, the bones of the wrist, vertebrae, etc.).
How connected?
The human skeleton (we will get acquainted with the name of the bones below) is a set of individual bones that are connected to each other. One or another order of these elements depends on their direct functions. There are discontinuous and continuous connection of human bones. Consider them in more detail.
Continuous connections. These include:
- Fibrous. The bones of the human body are interconnected by means of a pad of dense connective tissue.
- Bone (that is, the bone has completely grown together).
- Cartilage (intervertebral discs).
Intermittent connections. These include synovial, that is, between the articulating parts there is an articular cavity. The bones are held together by a closed capsule and the muscle tissues and ligaments that reinforce it.
Thanks to these features, the arms, bones of the lower extremities and the torso as a whole are able to set the human body in motion. However, the motor activity of people depends not only on the presented compounds, but also on nerve endings and bone marrow,which are contained in the cavity of these organs.
Skeleton functions
In addition to the mechanical functions that maintain the shape of the human body, the skeleton provides the possibility of movement and protection of internal organs. In addition, the skeletal system is a place of hematopoiesis. Thus, new blood cells are formed in the bone marrow.
Among other things, the skeleton is a kind of repository for most of the body's phosphorus and calcium. That is why it plays a critical role in mineral metabolism.
Human skeleton with bones name
The adult human skeleton consists of more than 200 elements. Moreover, each part of it (head, arms, legs, etc.) includes several types of bones. It should be noted that their name and physical features differ significantly.
Head bones
The human skull consists of 29 parts. Moreover, each section of the head includes only certain bones:
1. Brain region, consisting of eight elements:
- frontal bone;
- wedge;
- parietal (2 pcs.);
- occipital;
- temporal (2 pcs.);
- lattice.
2. The facial region consists of fifteen bones:
- palatine bone (2 pcs.);
- opener;
- zygomatic bone (2 pieces);
- upper jaw (2 pieces);
- nasal bone (2 pcs.);
- lower jaw;
- tear bone (2 pcs.);
- inferior nasal concha (2 pcs.);
- hyoid bone.
3. Middle ear bones:
- hammer (2 pcs.);
- anvil (2 pcs.);
- Stirrup (2 pcs.).
Torso
Human bones, whose names almost always correspond to their location or appearance, are the most easily examined organs. So, various fractures or other pathologies are quickly detected using a diagnostic method such as radiography. It should be especially noted that one of the largest human bones are the bones of the trunk. These include the entire spinal column, which consists of 32-34 individual vertebrae. Depending on the functions and location, they are divided:
- thoracic vertebrae (12 pcs.);
- cervical (7 pcs.), Including epistrophy and atlas;
- lumbar (5 pcs.).
In addition, the bones of the body include the sacrum, coccyx, chest, ribs (12 × 2) and sternum.
All of the named elements of the skeleton are designed to protect the internal organs from possible external influences (bruises, bumps, punctures, etc.). It should also be noted that in the case of fractures, the sharp ends of the bones can easily damage the soft tissues of the body, which will lead to severe internal hemorrhage, most often leading to death. In addition, for the fusion of such organs, much more time is needed than for those located in the lower or upper limbs.
Upper limbs
The bones of the human hand include the largest number of small elements. Thanks to this skeleton of the upper limbspeople are able to create household items, use them, and so on. Like the spinal column, the human hand is also divided into several sections:
-
human hand bones Girdle of the upper limb consists of a shoulder blade (2 pcs.) And a collarbone (2 pcs.).
- The free part of the upper limb has the following parts:
- Shoulder - humerus (2 pieces).
- Forearm - ulna (2 pieces) and radius (2 pieces).
-
The hand, which includes:
- the wrist (8 × 2), consisting of the scaphoid, lunate, trihedral and pisiform bones, as well as the trapezoid, trapezoid, capitate and hamate bones;
- metacarpus, consisting of the metacarpal bone (5 × 2);- finger bones (14 × 2), consisting of three phalanges (proximal, middle and distal) in each finger (except for the thumb, at which has 2 phalanges).
All presented human bones, the names of which are quite difficult to remember, allow you to develop hand motor skills and perform the simplest movements that are essential in everyday life.
It should be especially noted that the constituent elements of the upper limbs are subject to fractures and other injuries most often. However, such bones grow together faster than others.
Lower limbs
The bones of the human leg also include a large number of small elements. Depending on the location and functions, they are divided into the following departments:
- Lower limb belt. This includes the pelvica bone that consists of the ilium, ischium, and pubis.
- The free part of the lower limb, consisting of the thighs (femur - 2 pieces; patella - 2 pieces).
- Shin. Consists of a tibia (2 pieces) and a fibula (2 pieces).
- Foot.
- Tarsus (7 × 2). It consists of two bones each: calcaneus, talus, navicular, medial sphenoid, intermediate sphenoid, lateral sphenoid, cuboid.
- Metatarsus, consisting of metatarsal bones (5 × 2).
- Finger bones (14 × 2). We list them: the middle phalanx (4 × 2), the proximal phalanx (5 × 2) and the distal phalanx (5 × 2).
The most common bone disease
Specialists have long established that it is osteoporosis. It is this deviation that most often causes sudden fractures, as well as pain. The unofficial name of the presented disease sounds like a "silent thief." This is due to the fact that the disease proceeds imperceptibly and extremely slowly. Calcium is gradually washed out of the bones, which entails a decrease in their density. By the way, osteoporosis often occurs in old or mature age.
Bone aging
As mentioned above, in old age, the human skeletal system undergoes significant changes. On the one hand, bone thinning and a decrease in the number of bone plates begin (which leads to the development of osteoporosis), and on the other hand, excessive formations appear in the form of bone growths (or so-called osteophytes). There is also calcinationarticular ligaments, tendons and cartilage where they attach to these organs.
The aging of the osteoarticular apparatus can be determined not only by the symptoms of the pathology, but thanks to such a diagnostic method as radiography.
What changes occur as a result of bone atrophy? These pathological conditions include:
- Deformation of the articular heads (or the so-called disappearance of their rounded shape, grinding of the edges and the appearance of corresponding corners).
- Osteoporosis. When examined on an x-ray, the bone of a sick person looks more transparent than that of a he althy one.
It should also be noted that patients often show changes in bone joints due to excessive deposition of lime in adjacent cartilage and connective tissue tissues. As a rule, such deviations are accompanied by:
- Narrowing of the articular x-ray space. This occurs due to calcification of the articular cartilage.
- Strengthening the relief of the diaphysis. This pathological condition is accompanied by calcification of the tendons at the site of bone attachment.
- Bone outgrowths, or osteophytes. This disease is formed due to calcification of the ligaments at the point of their attachment to the bone. It should be especially noted that such changes are especially well detected in the hand and spine. In the rest of the skeleton, there are 3 main radiographic signs of aging. These include osteoporosis, narrowing of the joint spaces and increased bone relief.
Some people have these symptomsaging may appear early (at about 30-45 years), while in others it may appear late (at 65-70 years) or not at all. All the described changes are quite logical normal manifestations of the activity of the skeletal system at an older age.
This is interesting
- Few people know, but the hyoid bone is the only bone in the human body that is in no way connected with others. Topographically, it is located on the neck. However, traditionally it is referred to the facial region of the skull. Thus, the hyoid element of the skeleton with the help of muscle tissue is suspended from its bones and connected to the larynx.
- The longest and strongest bone in the skeleton is the femur.
- The smallest bone in the human skeleton is located in the middle ear.
