Growth varies from person to person and the increase in body length is continuous. Many factors play a role in growth. Growth can be divided into three phases. People do not always grow according to the species, which may be the result of heredity and diseases.
What is growth?
Growth varies from person to person and the increase in body length is continuous. Most of a person’s growth occurs through the multiplication of body cells. As cells divide, more and more of these cells are created. Until the human is fully grown, this process is repeated continuously. On average, humans grow until they are twenty-five years old. Growth is controlled by the human growth hormone somatotropin, which is channelled through the pituitary gland. Growth is faster at night because the concentration of growth hormone is highest during this time. Children grow at different rates and some factors play a role in determining average height.
Function and task
When the child is born, the head still makes up about a quarter of the body length. As the child grows, this changes. In children and adolescents, three phases of growth can be distinguished:
In the first phase, the period from birth to the third year of life, children grow the fastest. During this time, they can gain up to 45 cm in height. The growth rate decreases continuously. From the third year of life, we speak of the second phase of growth. This lasts until shortly before the onset of puberty. In this phase, children grow between five and six centimeters per year. In the third and final growth phase, which begins at puberty, people gain between seven to nine centimeters in height per year. The rate of growth peaks during this growth phase. Adolescents grow between 17 and 24 centimeters, with girls tending to grow slightly less than boys. On average, girls grow a little faster and are initially taller than boys. However, this evens out again in the course of puberty. With the end of puberty comes a standstill. The body size of adulthood is reached. Hormones play the biggest role in growth. They are messenger substances and pass on information between the cells, tissue and organs in the body. Only with sufficient levels of the hormone somatotropin can full adult height be achieved. This hormone regulates almost all growth processes that are important. It also promotes the conversion of body fat into energy, regulate blood sugar, and affect the immune system. Not only the hormone somatotropin plays an important role in the growth process. Heredity and a person’s lifestyle are also crucial. If the parents are short, for example, there is a high probability that the child will also not achieve excessive body length. Thus, already at the time of fertilization, it is approximately determined how tall the human being will become. Another decisive factor is the way of life the human being pursues during growth. In the case of permanent malnutrition or an inadequate composition of the diet (that is, too few proteins or vitamins are consumed), the growth process can be significantly impaired.
Diseases and ailments
Long-lasting diseases or disorders in the function of our glands can affect growth in a negative way. If, for example, a deficiency of the growth hormone sets in, the affected person suffers from short stature. In short stature, the anterior lobe of the pituitary gland does not work sufficiently and the child remains behind in physical development. The whole body gives the appearance of an underdeveloped person. If the thyroid gland does not secrete enough hormones even after birth, then this can affect not only the growth in length. These children suffer from myxedematous short stature, which can also impair cognitive abilities. By supplying the thyroid hormone, this defect can be corrected to a large extent. The opposite of short stature is tall stature. Here, the anterior pituitary gland works too fast during development. This peculiarity of growth can also become noticeable in the later years of life. In this phase, the growth of the bones is already completed.An increase in the length of the bones is then not possible, but the bones can then become larger at the ends and a tip enlargement develops (acromegaly). In this clinical picture, fingers and hands, as well as toes and feet, nose, lips and chin are enlarged. Taller people struggle more often with back problems. The body has to carry a heavy load, this manifests itself in the form of back pain. But small people also struggle in everyday life. Not only do short people on average rate their quality of life as lower, they also suffer more often from depression, anxiety and malaise. According to one study, people’s happiness increases with their size. However, the specific reason for this is not so much to be found in people’s biology, but more in the social values that define a certain size as attractive. In our age, thanks to modern medical advances, it is possible to determine the expected body size. An accurate method in this regard is the determination of bone age. Through this examination, a conclusion can be drawn about the expected growth. It is also possible to draw a growth curve in a somatogram. The body develops at the same percentile of the body length, which can predict what the future development will be approximately.
