Human skeleton, bones or skeletal system is the term for all bones that make up the human body. The adult human skeleton consists of 206 bones, but many of them are just forming or growing together in the course of individual development. That's why a newborn baby is 270, and a teenager can have up to 356 bones.

The human skeleton weighs an average of about 10 kilograms for women and 12 kilograms for men. In the first stage of development, the bones are connective tissue in nature, however, from the fourth to the sixth week of the embryo's life, separate cartilage foci form on this substrate, which then form a bone scaffold for the whole organism.

Human skeleton - structure

The human skeleton is mostly made up of bone tissue, but it is also composed of cartilage tissue. It consists of five categories of dice:

  • long bones(Latin ossa longa),
  • flat bones(Latin ossa plana),
  • pneumatic bones(Latin ossa pneumatica),
  • short bones(Latin ossa brevia),
  • various bones(Latin ossa multiformia).

In an adult human, 80 bones belong to the axial skeleton, which is made up of the skull, spine, ribs, and sternum. On the other hand, the remaining 126 bones form the skeleton of the upper and lower limbs and their rims.

Human skeleton - features

The basic functions of the human skeleton are:

  • protective function ,
  • enabling movement ,
  • supporting the body(maintaining the position of the body and internal organs, as well as the shape of the body),
  • production of blood cells ,
  • mineral storage ,
  • endocrine regulation .

Bones provide internal organs with protectionprotection from damage . The skull is the bone protection of the brain, the vertebrae form a channel that protects the spinal cord, and the ribs, spine, and sternum form a bony cage that protects the heart and lungs.

Thanks to the presence of joints and the interaction of muscles, the skeleton also allows the movement of individual limbs and the entire body. These movements are coordinated by a systemnervous.

Skeletonalso gives the human body shape and allows it to be kept upright . It also provides attachment or support points for internal organs. If it wasn't for the chest, the lungs would collapse, if it weren't for the spine and pelvis, the abdominal cavity would not have anywhere to settle firmly.

The bone marrow inside the bones is responsible forproduction of blood cells . This process is called haemopoiesis. In children, it occurs mainly in long bones, while in adults it also occurs in the vertebrae and sternum.

The skeletonstores numerous minerals , but the most significant amount of it is calcium, which is one of the main components of bone. The bone marrow, on the other hand, contains a lot of iron.

Bone cells also produce the hormone -osteocalcin . It serves, inter alia, to regulate blood sugar levels, stimulate testosterone production and fat deposition.

Human skeleton - disease and damage

The most common skeletal injuries are sprains, sprains and fractures. The bones are only for the latter. Young children and the elderly are particularly susceptible to them, especially those suffering from osteoporosis. The greater fragility of bones in them also results from the natural weakening of the bones in old age. On the other hand, in minors it is the effect of not fully developed skeleton.

A bone fracture is defined as a break in the continuity of bone tissue, accompanied by damage to the surrounding tissues. Bone fractures are divided intoopen(the fracture where the broken bone pierces the skin) andclosed(the skin and soft tissue above the fracture are intact). There are also fracturesstraight(there are only two bone fragments in the fracture line),with displacement of the bone fragments(i.e. there is no contact between them) ,articulariextra-articular ,transverseispiral , a evenbutterfly-shaped .

In addition to bone fractures and sprains and dislocations that affect the joints and surrounding structures, degeneration and spondyloarthropathies often occur within the skeleton, such as:

  • osteoarthritis ,
  • rheumatoid arthritis(RA),
  • ankylosing spondylitis(AS).

Popular skeletal diseases are also:

  • sterile bone necrosis ,
  • dysplasje ,
  • rheumatism ,
  • rickets ,
  • congenital fragilitydice .

Differences in the structure of the skeleton of men and the skeleton of women

The differences in the structure of the male and female skeletons are distinct, but they are much smaller than the differences in the structure and function of soft tissues. In addition to differences such as the size and weight of the skeleton (statistically larger, more durable and heavier in men), there are also differences in structure:

  • skulls ,
  • long bones ,
  • pelvis ,
  • dentition .

Differences in the structure of the skull are best seen in the midline of the nape, on the mastoid process of the temporal bone, brow bone and chin. There are also slightly more subtle differences in the dentition, especially in the canines.

Male long bones are usually larger and heavier than female long bones . Men also have a stronger site of muscle attachments which makes it easier for them to have more muscle mass.

The most significant differences, however, are in thepelvis . In females, it is wider and has a more inwardly curved sacrum. This creates a funnel-like structure that helps your baby travel from the uterus to the birth canal and facilitate labor.

Human skeleton - composition

The human skeleton consists of the head bones, which are divided into the bones of the skull and the craniofacial bones.

Bones of the skullto:

  • frontal bone,
  • right and left parietal bone,
  • occipital bone,
  • temporal bone right and left,
  • sphenoid bone,
  • ethmoid bone.

Facial bonesto:

  • nasal bone,
  • nasal septum (ploughshare, vertical plate of the ethmoid bone),
  • lacrimal bone,
  • zygomatic bone,
  • bone palate,
  • jaw (jaw bone),
  • mandible,
  • auditory bones (hammer, anvil, stirrup).

Another important group of bones aretorso bones :

  • spine (7 cervical vertebrae, 12 thoracic vertebrae, 5 lumbar vertebrae, 5 sacral vertebrae and 3 to 5 caudal vertebrae, so a total of 32 to 34 vertebrae),
  • ribs (12 pairs),
  • bridge.

The bones of the upper limbare divided into:

  • bones of the upper limb girdle (shoulder blades and collarbones),
  • arm (humerus),
  • forearm (radius, ulna),
  • hand.

Handin turn consists of:

  • wrist (navicular bone, lunate bone, triangular bone, pea bone,major trapezius, minor trapezius, capitate bone, hook bone),
  • metacarpal bones,
  • fingers (phalanges): thumb, index finger, middle finger, ring finger, little finger.

Thebones of the lower limbconsist of:

  • lower limb girdle (colloquially known as the pelvis and divided into the smaller and larger pelvis. The pelvis includes: the hip bone, ischium bone, pubic bone and pubic symphysis),
  • femur,
  • patella,
  • shin (tibia, fibula),
  • foot.

The footis made of the following bones:

  • tarsal bones (talus bone, calcaneus bone, navicular bone, wedge bone, cuboid bone),
  • metatarsal bones,
  • finger bones (including the big toe).

Bibliography

Bochenek A., Reicher M., "Human Anatomy", volume I, PZWL Medical Publishing, Warsaw 2012.

Category:

Anatomy