Physiology- The law
Knowing you human body country
3) Let’s know the environment that your people live in:-
About 60% of the well-established human body country (i.e. adult human body) is fluid, mainly, with water solution of ions and other substances, which are nutrients or food for people. This means that your environment does not contain air and thus the transportation system is tunnels (blood vessels) filled with the fluid required for transportation. However, your people needs oxygen for respiration, which is found in air outside your country, so, your country, has the air-supplying agency, which is not found in the real life.
But, this fluid, which represents 60% of your body (country), is distributed as the following: –
- Most of this percentage of this fluid is in the internal structure of your people (i.e. cells) and called intracellular fluid. In which they oxidize glucose to produce energy. You can say that is the digestive system of your cell or person.
- One third of this percentage is in the spaces outside the cells (i.e. the interstitial spaces) and is called the extracellular fluid OR interstitial fluid OR internal environment. You can say that it is the sea in which your cells or people live. This extracellular fluid is the environment that your people live in. What are the characteristics of this environment?
- This fluid is in constant motion in the tunnels (blood vessels) and between the people or cells, where it is transported rapidly through the blood or the transporting system and then diffused through the capillary walls (the smallest blood vessels or tunnels that enters between the cells in the tissue or you can say, reaches the small districts in which small groups or cells live) and taken by the cells and mixed with the fluid inside the cells (the interalceullar fluid).
- This extracellular fluid contains the ions and nutrients needed by the cells to maintain cell life.
- All cells live in the same extracellular fluid, which means in the same environment, thus this environment can be called the internal environment.
What is the difference between the Extracellular and Intracellular Fluids?
- The extracellular fluid: Contains both the nutrients or the food of your people and also the wastes resulted from the Energy-producing chemical reactions (or from the digestion of the nutrients by the cells or you people): –
- The FOOD for the cells (or people) is large amounts of sodium, chloride, and bicarbonate ions plus nutrients for the cells, such as oxygen, glucose, fatty acids, and amino acids.
- The WASTES (or Sewage) from the cells (or people) is carbon dioxide (CO2), resulting from the respiration process of the people, plus other cellular waste products that are being transported to the kidneys for excretion such as urea and creatinine.
- The intracellular fluid: differs significantly from the extracellular fluid. It contains large amounts of potassium, magnesium and phosphate ions instead of sodium and chloride ions. The concentration of these ions is controlled by special mechanisms.
The role of physiology or the function of the automated coordination system is how to maintain this internal environment in constant conditions.
These mechanisms, through which the automated coordination maintain constant internal environment, are called HOMEOSTASIS.
We will talk about HOMEOSTASIS in the next topic. so, be with us