Biology is a natural science concerning the study of life and living organisms and all the related stuff.
Anatomy is the study of the body and body parts.
Physiology is the study of the functions of living organisms.
Can you see the 3 as the same argument, from different points of view? Can you see biology as general container, anatomy and physiology as “blocks” of biology? Or maybe biology as a full study course and anatomy and physiology as 2 of the many exams you need to pass to become doctor in biology?
So we have the main subject “life” that has been examined, divided and studied under different points of view to make a full systematic and organized study course… this organization is necessary for an easier approach and understanding… unless you like to have only one book, 15.000 pages, for tomorrow written assignment on page 1 to page 7.500…!!!
Organization is the key!
Our body is a fully integrated organized whole… this is the only way we must consider it!
Obviously if we want to understand it, its parts, its functions, how it grows, works, evolves and decays we need to spread the whole argument into different levels of organization.
All around there are infinite atoms, the basic unit of matter, these are the bricks building everything… in the past they were considered the littlest unit… obviously even a brick must be made of something, so are atoms… but now we’re going to examine from atoms up! Atoms will join in molecules, than there can be macromolecules and organelles… and finally we get to the first step in the ladder of life: cells!
This is how we are organized
1- Cellular level. Cells are the smallest living entity constituting us, we are literally made by trillions of cells living in the same way we live, with the same needs… nutrients, energy, to expel waste, to reproduce and so on!
2- Tissues. Cells are not all equal, they have a life and in their life they may become involved in different processes, they tend to specialize on particular functions -a nervous cell is similar but different than a muscular cell!- and to aggregate together to achieve that particular function. When similar cells aggregate together for a specific function we call them tissues. We have 4 possible types of tissues:
3- Organs. When different tissues organize together for a specific function they form an organ. Heart, brain, lungs, stomach… all organs, that means they’re different tissues organized together, every tissue formed by many cells with similar specialization. For example the stomach is made of epithelial tissue (the lining), connective tissue (blood), muscular tissue (that makes it contract to help the digestive process), nervous tissue (commanding and regulating all the process).
4- Systems. Groups of different organs working together for the same function are defined systems… the digestive system is made of esophagus, stomach, liver, small intestine, large intestine and other organs, everyone has a specific role, together they work to transform the food you get from outside, absorb the nutrients and expel the waste. Your bones are organs (yes, they’re made of different tissues so they classify as rigid organs!) organized together as a skeletal system to give you a shape, protect other internal organs and so on. Then we have the muscular system, nervous system, lymphatic system, respiratory system, circulatory system and more!
5- Organism. This is you! You are a living organism that is made by the union and the organization of trillions of cells in tissues, organs, systems to permit you to move, enjoy and support all the basic vital functions.
At this point some considerations on who we are and what we are… for sure if you think enough you will answer that you are not any of your systems or organs or tissues or cells and at the same time you are all of them… what we are is really the living union of different living parts… at the same time these parts are the union of other living parts… until you reach a level, cellular level, that is the union of other -non living- parts as atoms or molecules… what is the difference between a cell and a molecule? well, we could say that in a cell all the components are organized in some way for a combined result that is life, while in molecules there are only atoms bound together doing nothing.
– we are the union of trillions of parts -again the concept of union, the the meaning of yoga!
– all the parts are organized together for a common function
– the organized union is the difference between living and not living (cells vs molecules)
Do you agree?