Basics of cellular energy (Pt. 1)
We have seen how the health of the body depends on fluidity and pressure. Fluidity allows the blood to circulate unimpeded and easily under the pressure exerted by the heart. Only when this is the case can our cells be oxygenated, receive nutrition and detoxify themselves. Proper circulation, therefore, could be said to be one the most important aspects of our health, and the reason why the “Heart and Body Extract” is such a great addition to our health protocol.
Good circulation is also key because it allows the movement of intracellular and extracellular fluids to be transported throughout the body, allowing nutrients to be carried to the cells so they can manufacture the energy they need to do their job. Many health care professionals believe it is the ability of the cell to manufacture energy that is at the core of many cardiac disease disorders. This is the case of ‘ischemic heart disease’, ‘congestive heart failure’ and ‘cardiomyopathy’ (1).
In today’s blog, we will focus on the role of circulation in the cell’s ability to manufacture energy.We will look at the microscopic cell, its main functions and parts and how its ability to make energy influences heart health.
The microscopic cell
When we consider the health of our body, it is easy to think of only organs, like the heart. But we need to remember that each organ in our body is ‘an aggregate of many different cells’(2). Because of this, the health of our organs depends on the health of each microscopic cell.
So, what is a cell? Cells are the ‘basic structural, functional, and biological unit of all known living organisms’(3). Each of the 100 trillion cells in the human body is a ‘living structure that can survive indefinitely and even reproduce itself, provided its surrounding fluids contain appropriate nutrients’ (2).
Each specific cell is specially adapted to perform one or more functions, like the heart cells. However, despite the differences, all cells have the same basic characteristics. For instance, in all cells oxygen combines with the breakdown products of carbohydrates, fat or protein to release the energy required for cell function. What is more, the basic mechanism for turning nutrients into energy is basically the same in all cells. In this sense, all cells deliver the end products of their chemical reactions into the surrounding fluids.
Composition of the cell
The cell is a complex unit composed of highly organized physical structures called ‘organelles’. The two major parts of the cell are the ‘nucleus’ and the ‘cytoplasm’, both separated from each other and the surrounding fluids by a barrier called ‘membrane’. They are all equally important to the functioning of the cell, but the mitochondria provides 95% of the cell’s total energy supply(2).
The substances that make up the cell are called ‘protoplasm’ and they are: water, electrolytes, proteins, lipids and carbohydrates.
- Water: It is the main fluid medium in cells at a concentration of 70-85%. Many cellular chemicals are dissolved in water and this allows many chemical reactions to take place.
- Electrolytes: The main electrolytes in the cell are potassium, magnesium, phosphate, sulfate, bicarbonate, and small amounts of sodium, chloride, and calcium. Electrolytes provide inorganic chemicals for cellular reactions. On the cell membrane, for example, they allow transmission of electrochemical impulses in nerve and muscle fibers.
- Proteins: They are 10-20% of the total cell mass. They are divided into ‘structural proteins’ and ‘globular proteins’. The structural proteins are present in hair, collagen and elastin fibers of connective tissue, blood vessels, tendons, ligaments, etc. The globular proteins are the enzymes of the cell and are soluble in the cell fluid. Enzymes catalyze chemical reactions, an example is the chemical reaction that splits glucose into component parts and combine these with oxygen to form carbon dioxide and water, providing energy for cellular functions.
- Lipids: They are soluble in fat solvents. The most important ones are phospholipids and cholesterol, which together add up to 2% of the cell’s total mass. Because they are insoluble in water they make up the cell membrane and the intracellular membranous barriers that separate the different cell compartments.
- Apart from cholesterol and phospholipids, we can also find triglycerides, which make up 95% of the cell’s mass. The fat stored in these cells are the body’s main storehouse of energy-giving nutrients that can be dissolved and used for energy when the body needs it.
- Carbohydrates: They play a major role in the nutrition of the cell. Carbohydrates in the form of dissolved glucose are always present in the surrounding extracellular fluid as a form of readily available energy for the cell. A small amount is always stored in the cell in the form of glycogen, which is a source of quick energy. Most human cells do not contain large stores of carbohydrates, only around 1%. 3% is found in muscle cells and sometimes up to 6% in liver cells (2).
Extracellular fluid, the internal environment
We have seen how our body is mostly made out of water, and how water balance is very important. When it comes to the health of our cells, it is key to understand how fluid is kept in the right places. Some of this fluid is inside the cells and is known as intracellular fluid, but some other is in the spaces outside the cells, known as extracellular fluid.
In the extracellular fluid are the ions and nutrients needed by the cells for maintenance of cellular life. Because this extracellular fluid is in constant motion, its contents are rapidly being transported in the general circulation and then mixed between the blood and the tissue fluids through the capillary walls.
Basically, all the cells in our body live in this extracellular fluid, and because of this it is called ‘internal environment of the body’. The key aspect to understand here is that this internal environment determines the health of the cells and their ability to make energy,‘As long as the proper concentrations of oxygen, glucose, ions, amino acids, fatty substances and other constituents are available in this internal environment’(2).
Differences between the extracellular and intracellular fluid
The extracellular fluid contains large amounts of sodium, chloride, and bicarbonate ions, plus nutrients for the cell: oxygen, glucose, fatty acids, and amino acids. It also contains carbon dioxide that is being transported from the cells to the lungs to be excreted, plus other cellular products that are being transported to the kidneys for excretion.
The intracellular fluid differs from the extracellular because it contains large amounts of potassium, magnesium,and phosphate ions instead of the sodium and chloride ions found in the extracellular fluid. Special mechanisms for transporting ions through the cell membranes maintain these differences. In other words, the extracellular fluid contains a large amount of sodium but only a small amount of potassium, and the exact opposite is true of the intracellular fluid. These differences between the inside and the outside of a cell are extremely important for the life of a cell.
Maintaining the ion balance requires energy. The proper flow of ions into and out of the heart is required to keep the heart cell from filling with water (cardiac edema) and to keep the electrolytes present that allow the heart to beat avoiding irregular heartbeats.
The role of circulation in cell health
Extracellular fluid is transported through all parts of the body in two stages:
During the first stage, the extracellular fluid is transported in the circulatory system as the blood moves around in a circular motion from heart to the lower parts of the body and back up again. All the blood in the circulation moves through the entire circulatory system an average of once every minute when the body is at rest and as many as six times each minute when a person becomes extremely active.
During the second stage, the extracellular fluid is transported via the movement of fluid between the blood capillaries and the cells: As blood passes through the capillaries there is a continual exchange of extracellular fluid between the blood and the interstitial fluid in the intercellular spaces. This is possible because the capillaries are porous and allow large amounts of fluid and its dissolved nutrients to diffuse back and forth between the blood and the tissue spaces. The fluid and dissolved molecules are continually moving and bouncing in all directions within the fluid themselves and through the pores and through the tissue spaces.
How nutrients are distributed through the different organs
As the extracellular fluid, both that of the plasma and that in interstitial spaces is continually being mixed, it allows complete homogeneity throughout the body.Then, as blood circulates through the different organs, nutrients are distributed in the following way:
1) Respiratory system: Every time the blood circulates through the body it also flows through the lungs. There, the blood picks up oxygen that the cells need. Carbon dioxide is released from the blood into the lungs and the respiratory movement of air into and out of the alveoli carries the carbon dioxide to the atmosphere.
2) Gastrointestinal tract: A large portion of the blood pumped by the heart also passes through the walls of the gastrointestinal organs. Here, different dissolved nutrients like carbohydrates, fatty acids, and amino acids are absorbed from the ingested food into the extracellular fluid.
3) Liver: Not all substances absorbed from the gastrointestinal tract can be used in their absorbed form by the cells. The liver changes the chemical compositions of many of these substances to more usable forms; then other tissues of the body, fat cells, kidneys, etc help to modify the absorbed substances or store them until they are needed.
4) Kidneys: Passage of blood through the kidneys removes most of the other substances besides carbon dioxide from the plasma that are not needed by the cells, such as urea and uric acid. They include excesses of ions and water from the food that might have accumulated in the extracellular fluid. The kidneys perform their function by first filtering large quantities of plasma then reabsorbing those substances that are needed by the body into the blood: glucose, amino acids, water and ions.