Bones are made of organic and inorganic components, which gives them strength, stiffness and resistance to injuries. There are 206 bones in the human body that are essential for movement, protecting delicate internal organs such as the brain, and producing blood cells.

Contents:

  1. Dice - types of dice
  2. Bones - internal structure
  3. Dice - dice composition
  4. Bones - bone marrow
  5. Bones - periosteum
  6. Bones - bone vascularization and innervation
  7. Dice - Features

Dice - types of dice

We distinguish:

  • long bones
  • short bones (their length is equal to their width)
  • flat bones
  • irregular bones
  • sesamoid

The long bonehas one dimension - length - much greater than the other dimensions, ie width and thickness. An example of a long bone is:

  • humerus
  • femur
  • forearm bones
  • shank bones

Long boneconsists of a shaft and two ends, which are called epiphyses at a young age, and are separated from the shaft by bands of cartilage, allowing the bone to grow in length. When growth is complete, the cartilage disappears. There are articular surfaces on the epiphyses of the bones. Thanks to their various shapes and convexities, they can form joints and serve as a place for the attachment of ligaments and muscle tendons.

Short bonesresemble cuboid-shaped solids with all dimensions similar. These include the tarsal bones and most of the wrist bones.

Multiform bonesare a group of irregularly shaped bones. Examples are the vertebrae and the sphenoid bone.

Pneumatic bonescontain air-filled sinuses which make them lighter. They are located in the skull.

There are many structures on the surface of the bone that serve mainly to connect with other elements of the musculoskeletal system. We distinguish:

  • tumor, lump, tuberosity
  • condyle, epicondyle, comb, spike, appendix, hillock
  • bottom, dimple, furrow
  • hole, channel, slot

Bones - internal structure

Bones are made of dense bone and spongy bone.

The compact creatureoccurs firstall in the epiphyses of long bones, as well as in the interior of flat bones, short bones and various shapes. It primarily creates the arms of long levers in the skeleton - it builds the shafts of long bones.

A compact creature viewed under a microscope has a complex structure. It consists of the Havers systems - the osteons.

Osteonis an arrangement of 4-20 bone plates. The larger lamellae cover the smaller and smaller ones, and in the center is theHavers Channel . Between the plaques there are bone cells - osteons. This structure ensures high strength of the bones.

Spongy creaturecreates bone trabeculae with pits between them. The arrangement of the trabeculae is constant for the same bones and restores after fracture. Bone has a high resistance to compression and stretching, but not bending. As a result, fractures occur.

Dice - dice composition

Bone tissue consists of:

  • intercellular essence consisting of
    • from the organic part - osteoid, which is about 25% of the tissue mass
    • inorganic part - mineral s alts constituting approximately 60-70% of the tissue mass
  • cells:
    • osteoblasts
    • osteocytes
    • osteoclasts

which account for about 5% of the bone mass

Bones - bone marrow

The bone marrow is the soft tissue that fills the inside of the bones.

We distinguish between:

  • yellow bone marrowconsisting mainly of fat cells, the content of which increases with each individual's age - this type of bone marrow is not involved in the formation of blood morphotic elements
  • red bone marrow , which is the place where erythrocytes, leukocytes, and thrombocytes are formed

In a child, the red bone marrow fills all bones. Over time, the red marrow turns into yellow in such a way that in adults, red marrow is only found in flat bones:

  • bridge
  • vertebrae
  • ribs
  • paddles
  • in the epiphyses of long bones

Bones - periosteum

The periosteum is the fibrous membrane that surrounds the bone from the outside. It consists of two layers: outer and inner.

The inner layer that adheres to the bone surface has bone-forming and regenerative properties. The osteoblasts present in it affect the production of new bone layers - the bone grows in length or the fracture fissure is filled.

The periosteum is strongly innervated. High pain sensitivity is due to the presence of sensory fibers. Nerves penetrate the inside of the bones through the nutrient holes.

Bones - bone vascularization and innervation

Long bones are vascularized by various types of arteries:

  • nutritional
  • periosteal diaphysis
  • sockets
  • nasal

Bone veins accompany arteries.

Dice - Functions

Dice have various functions:

  • they form a scaffolding, i.e. a support for the body, giving it shape and size
  • are passive locomotor organs that are moved by connections to the muscles
  • are a storehouse of calcium and phosphorus
  • they protect important organs, for example the bones of the skull - the brain, the bones of the spine (vertebrae), the spinal cord

Category:

Anatomy