Beijing time on November 5, according to foreign media reports, bones are a very magical thing. It is rarely realized that bones are actually a living tissue. They can repair themselves after breaks or breaks, but in addition, they constantly reshape their form according to our daily activities. In this article, we’ll introduce you to some interesting facts about human bones.
1. Not everyone has 206 bones.
The textbook notes that human bones include a total of 206 bones. But babies are born with more than 300 bones in their bodies. These bones start with cartilage and then gradually mineralize in the first few years of life. In this process, some bones will fuse together.
Some people are born with more bones than others, such as one rib, finger, or toe. Some people even grow up with extra bones. A recent study showed that more and more people are re-growing “bean bones” (a small bone in the shape of a bean, located behind the knee) as a result of improved nutrition and weight gain.
2. The height of human bones will change
The height of a child changes most rapidly in the first year of life. By the middle and late adolescence of puberty, we are basically reaching adult height. But even if the bone no longer grows, height can still change.
The bones at the joints are covered with a layer of cartilage, a layer of rubber-like tissue made up of water, collagen, protein polysaccharides, and cells. After a day, cartilage throughout the body (especially in the spine) is compressed under gravity. So every night you’ll be shorter than when you get up in the morning. After a good night’s sleep, the cartilage returns to its normal size. In space, the microgravity environment does the opposite: astronauts can increase their height by up to 3% after a mission in space.
Not just cartilage, but even the bone itself gets shorter under the influence of impact. Scientific studies have shown that the impact of running can temporarily shorten the tibia by 1 mm.
3. Only one bone is not connected to other bones
Most of the bones in the human body do not exist in isolation, such as the hip bone is connected to the thigh bone. But not all bones are like this, and the only exception is the tongue bone.
The tongue bone is U-shaped, located at the bottom of the tongue, fixed by the muscles and ligaments at the bottom of the skull and the upper jaw. This bone allowed humans (and Neanderthals) to speak, breathe and swallow.
Fractures of the tongue bone are very rare. If an autopsy reveals a broken tongue bone, it may be used as evidence of strangulation or self-inflicted stoicism.
4. Bone marrow is not just to fill the inside of the bone
Longer bones, such as thigh bones, are filled with bone marrow made up of fat cells, blood cells and immune cells. The bone marrow in the child is red, reflecting the role that bone marrow plays in the production of blood cells. The bone marrow in adults is yellow, which contains 10% of the body’s fat. For a long time, it was thought that fat cells in bone marrow had no choice but to fill space. But scientists have recently discovered that the fat inside the bone actually has important metabolic and endocrine functions that can have an impact on overall health.
5, the smallest bone in the ear
The smallest bones of the human body are hammer bones, cheekbones and tibia, collectively known as “listening bones”. Their role is to transmit vibrations in the air to the liquid in the inner ear. These are not only the smallest bones in the human body, but the only ones that will not be reshaped after the age of one. This is important because changes in bone shape can affect hearing.
Hearing small bones also plays an important role in archaeology and forensics. Because the bones are already formed when the embryo is still in the mother’s womb, isotope analysis can help experts analyze the eating habits and health of mothers with unknown adult bones.
6. Bones can cause pressure
The sympathetic nervous system is the body’s response to intense activity, known as a “fight or escape” response. Scientists generally believe that the reaction is related to the body’s nervous production of epinephrine. But in a recent paper, researchers point out that osteocalcin released by osteoblasts is a key hormone in stress response.
Compared to other normal mice, mice fed in a special way and unable to secrete osteocalcin did not produce a “fight or escape” reaction in an emergency. The scientists also analyzed bone calcin levels in the body and found that subjects experienced an average increase in osteocalcin water in their blood and urine after stress. In addition, osteocalcin also stops the “rest and digestion” reaction of the parasympathetic nervous system in a relaxed state, thus activating the “fight or escape” response.
The protective effect of bones on the body has long been known. But who would have thought that bones could provide such an important physical protection besides physical protection?