What's wrong with the diet? Physiological component of the diet.

Chapter 16. Physiological individuality

What we explore: What does physiological diversity mean in humans?

What's new: How does heredity affect human anatomy?

What we will learn: How does environmental change affect phenotype?

1. A correct understanding of ... the diversity of people is based, therefore, on an understanding of two fundamental features of the organism: first, each organism is the subject of constant development throughout its life; secondly, a developing organism at each moment is under the joint influence of active genes and the environment (Levontin R. 1993) [1].

2. Correct understanding. Each person is identical to another in the external and internal composition of his body. Each of us has a body made up of many cells that form the tissues, organs, and systems of the body. Each of us has body tissues: connective, muscle, nervous, and epithelial. Each of us has organs: brain, heart, lungs, liver, etc. Each of us has systems consisting of tissues and organs of the body: cardiovascular, nervous, circulatory, digestive, etc. [2]. All cells, tissues, organs, and the systems of the human body formed from them consist of chemical elements and all this is identical for each person. But what then determines the individuality of the physiological structure of the body? This is his heredity and environment [3]. At the same time, heredity, which is characterized by processes of constant development and change, is under the constant influence of the environment throughout a person's life.

3. Heredity. From the fertilized female egg to old age, every person undergoes age-related changes, which are reflected in his appearance (including the face), height, and physique. These transformations are embedded in its genotype *, which closely interacts with the environment. A person's genotype reflects the physiological differences that manifest themselves in his anatomy.

* The genotype, through the sperm and egg at the moment of conception, absorbs what is hereditary - a set of DNA molecules, genes that are contained in the nucleus of a fertilized egg (Levontin R. 1993) [1].

4. Individual differences in anatomy. Anatomy (the science of the structure of the body) as a part of human physiology, based on numerous observations of many researchers over hundreds of years, in different countries and laboratories, has established thousands of variants (differences) of the same cells, tissues, organs, and systems:

• "Over the years, we have observed thousands of anatomical variants, the frequency of which can be predicted, and which have been observed in many cases over hundreds of years by many researchers in many countries and many laboratories. These differences arise primarily due to our genetic makeup, inherited from our ancient origins. It is important to understand that no two living organisms are structurally or functionally identical - animals or plants!" (Bergman, Ronald A., and R. A. K. Miyauchi) [4].

At the same time, hereditary individuality affects all structures of the body, preserving their viability, but there may also be painful deviations:

• "Many or most variations are completely harmless; some represent errors in the timing of embryological development** or the persistence of an embryological state. Some of these variations can seriously damage parts of the muscular, vascular, nervous, skeletal, and/or other organ systems" (Zytkowski, Andrzej, et al. 2021) [5].

* Embryological development (embryo from other Greek ἔμβρυον, or embryo) - the development of the embryo in the uterus during the first eight weeks after fertilization, at the beginning of the ninth week the embryo is called "fetus". The sequential order of development of the embryo may contain errors in the time of development and then the embryo stops in development without becoming a fruit. This condition is called either errors in the timing of embryological development or preservation of the embryological state.