The human body and its composition:

The living human body is made of cells They are the smallest structural and functional units in the body, and these cells come together to form tissues Which, in turn, compose devices systems. And integrate different body systems to carry out different biological functions. The process of benefiting from food takes place in all body systems to carry out various biological functions in the best way with joint coordination. The food cycle begins in the body by eating it orally, as it passes through the digestive system, in which it is digested and absorbed, and its digested elements are transferred through the blood circulation to the liver and other body tissues, where various catabolism and anabolism processes take place, through which the energy of nutrients is released and transformed into multiple forms that the body needs, as well. Waste resulting from metabolism is excreted, while other parts of the nutrients are used in the processes of anabolism and the formation of synthetic parts in the body that replace the damaged cells. It also leads to cell division and the growth of the body and the formation of its tissues, that is, it fulfills two main purposes, which are maintenance And growth. The surplus portion of many of the nutrients consumed is stored in appropriate forms such as fats Glycogen, or fat-soluble vitamins Or mineral elements such as iron and zinc.

It is clear, then, that our bodies ultimately consist of the nutrients that we eat or enter the body mainly through food. The human body is made up of the food that he eats, and the chemical elements of food are what make up the structure of his body. Al-Biruni mentioned that in his book “Al-Mediat” and it has become a general information in our time [1].

There are several methods of studying body composition. We may deal with it in terms of “A” the chemical elements included in its composition, or “B” in terms of nutrients and their groups that originally came from food, which include water, carbohydrates, fats and proteins, or “C” we deal with its study in terms of its tissues, apparatus, functions and composition. Below is a brief review of each of these aspects.

Body composition of chemical elements:

The human body has at least 42 chemical elements from the periodic table elements that make up the composition of its various tissues and the nutrients they contain. Table 1 shows a list of these elements and an approximate quantity of the most important ones. Carbon, oxygen, hydrogen and nitrogen make up about 96% of the body weight. These four non-metallic elements are included in the composition of water and organic compounds in the body. As for the remaining 4%, it is made up of mineral elements [2].

The mineral elements, according to their quantity in the body, have been classified into macroelements And microelements The macro elements can be defined as those elements whose quantity exceeds 0.05% of the body weight (see Table 1). They include seven elements: calcium - which is the most quantitative - phosphorous, sodium, potassium, chlorine, magnesium, and sulfur. As for the microelements, which are also called trace elements. They are the rest of the elements, and they consist of three groups according to the degree of their necessity for the body [3] as follows:

1. Basic microenvironment elements essential microelements They are iron, copper, zinc, iodine, manganese, cobalt and molybdenum, and selenium, chromium and fluorine can be attached to them.

2- The semi-essential microelementsAnd they are those elements to which some "necessary" or basic conditions apply [4]. These elements are tin, nickel, vanadium, arsenic, strontium, and silicon. Lead was added to it in 1976 and cadmium in 1978 [5,6]. Some scientists also added to it elements bromine, barium and boron [7, 8].

3. microenvironment elements of non - core non essential trace elements, Which are the elements mercury, bismuth, aluminum, antimony, germanium, gold, silver, titanium and rubidium. This group includes the elements that can be detected in the body by means of analysis available to humans at the present time, and which can measure concentrations that are not less than 10-12 grams. It is expected that all the elements of the periodic arrangement in the body are present in very small quantities. Man is from the soil of this earth and his food originated in the dirt.

It should be noted here that the conditions established by scholars for the basic elements or

Necessary in higher animals than mammals and birds, which can be summarized in the following seven points [3, 4]:

1- The presence of the mineral component in the body and its tissues in relatively constant quantities without significant variation.

2- Deficiency of the component leads to structural and physiological changes and clinical symptoms.

Table 1- The general chemical composition of the body of chemical elements

3- Adding the ingredient removes pathological and physiological changes.

4- The pathological physiological or structural symptoms are associated with specific biochemical changes that can improve and return to normal when the deficient component in the food is added.

5- The degree of necessity of the element must be proven in more than one animal species.

6- The degree of necessity of the element must be proven by more than one researcher and in more than one laboratory.

7- You must know the exact mechanism of the mode of action Metallic element.

 

Body composition of nutrients:

The living body contains the groups of nutrients that we have referred to, which are water, carbohydrates, fats, proteins, mineral elements and vitamins, as in Table No. 2. The proportion of these components varies according to age, physiological condition, pathology and degree of activity. The most varied among these ratios are the ratio of water and fat, as the percentage of water decreases in the case of obesity, while the percentage of fat increases.

Table 2- Approximate body composition of nutrient groups [8]

Vitamins are present in the body, but they do not constitute a percentage due to their small amount.

The percentage of water decreases with age, and the percentage of fat increases accordingly. While the percentage of water in the fetus is about 93%, it is about 70 - 75% in a newborn child, and ranges from 55 - 65% in a non-obese adult [8]. The ratio of water and fat also changes according to the physiological state, such as pregnancy and lactation, and according to the two health states

And disease. In the case of morbid obesity, the fat percentage may increase to reach 70% of the body weight. The most important place for fat storage in the body is adipose tissue that contains fat in the form of triglycerides..

Water is an important component in all tissues and parts of the body, but its percentage varies from one tissue to another. It is 92-90% in blood plasma, 78-72% in muscles, 54% in bones, and 5% in tooth enamel [9] .

The proteins Proteins It is present in every cell of the body, and comes in its proportion after water in the soft parts of the body, such as muscles, glands and connecting tissues. It is also found in the endothelial tissues lining the skin, internal channels in the body, hair and nails, as well as in the blood in the form of hemoglobin or hemoglobin and serum proteins.

As for carbohydratesIts quantity is relatively small, and its average does not exceed 1% of the body weight, and it is found in the form of animal starch or glycogen."About 350 grams are distributed in the liver and muscles, which in the case of satiety is equivalent to 5% of the weight of the liver and 1% of the muscle weight." It is also found in the form of blood sugar or glucoseAnd some complex carbohydrates such as glucorunic acid And hyaluronic acid

hyaluronic acid It is included in the synthesis of heparin And nucleic acids.

As for vitamins, they are found in the different cells of the body, and the most organs contain them is the liver, which is the main storage place for fat-soluble vitamins, which are vitamins that can be stored in relatively large quantities, unlike the water-soluble vitamins, which are rapidly depleted from the body due to not being stored in high quantities. However, vitamins are not expressed as a percentage in the body due to their small quantity in it.

Mineral elements are concentrated in specific parts of the body, such as the skeleton and teeth, which contain most of the calcium and phosphorous in the body. They are also distributed in the liver, where a large number of them are stored in it, as well as in the spleen, muscles and the rest of the body tissues.

 

Body tissues and organs:

The anatomically and functionally, the body is made up of units that are cells that come together to form tissues and organs. And the cell isSmallest independent anatomical and functional unit. The simplest types of organisms are bacteria Yeasts yeasts It consists of one unit that performs all the vital functions of breathing, food, digestion, absorption, metabolism, excretion and reproduction. In the case of advanced animals and humans, the cells of the body do not perform these functions alone, but rather as part of cooperation, coordination and complementarity with each other.

Scientific progress has helped us to understand the structure of cells and their various parts. Electron microscopy enables us to study the cell enlarged a hundred thousand times, and to identify its various functional parts.

Cell structure:

Figure 1 shows an approximate picture of a typical cell in the body, and it shows several parts, the most important of which are:

1- The cell membrane That surrounds the living matter in the cell, maintains its internal components, and achieves a dynamic balance with the environment.

2. The core nucleus It contains DNA Which carries the genetic traits in the cell, through which protein synthesis is directed.

3. cytoplasm "cytoplasm" Cytoplasm. And it has many organelles Live, inanimate substances expressed as inclusions. The most important organelles found in the cytoplasm are mitochondria Particles case Iysosomes. Mitochondria are organic or spherical particles of varying size that contain hundreds of enzymes responsible for energy production reactions. Mitochondria is the place where energy is produced in the cell and converted into ATP High energy. As for the lysosomes, they are small spherical or oval-shaped particles with a digestive function that contain enzymes that are effective in digesting the damaged parts of the damaged cell and the germs.

4- The endoplasmic reticulumIt is a group of membranes distributed in the cytoplasm, which form flat pages linked together that contain ribosomes. In which proteins are synthesized.

5- The Golgi apparatus. It contains flat cystic membranes to store and concentrate cell secretions and release them when needed [9]
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(The Book of Food and Nutrition) belongs to a large group of Arab scholars