Monday, January 9, 2017

Introduction & Foundational Concepts

First question that we must answer – What is vitalism?

Vitalism, simply put, is the idea that the whole is greater than the sum of its parts.  That there is an indefinable something that keeps the whole running – when that something is gone, the whole is no longer whole.  It is intangible, and immaterial.  But VITAL to the function of all living things.

When you die, what happens?  Your body shuts down, the parts no longer function as they once did.  But all the materials are still present – your lungs still exist, your digestive system is likely intact, ditto for the heart, the brain – organs present but no longer functioning – there is a vital spark that is missing. 

Dr. Frankenstein created his monster from parts of bodies he collected from the graveyard.  Even with carefully sewing the right parts together, the body needed a vital spark – LIFE – to function.  In Mary Shelley's book, he got it with lightening, adding a literal spark to the conglomerate body he had made.  The truth of the matter, however, is that electricity and lightening isn't the vital spark that makes us run.  Electricity is an essential part of our bodies, true – our muscles use electricity to contract, and ditto for information going through the nervous system.  But electricity is only the message, it is not what creates the message.

In Chiropractic, we call that vital force Innate Intelligence, and we say that it's in every living thing, in fact, the Chiropractic “Meaning of Life” is described as the expression of innate intelligence through matter.  It is not a strictly chiropractic concept (although the term Innate Intelligence is) – in Indian Philosophy, the Sanskrit word is prana - described as a vital life force.   In Eastern Philosophy, it's called qi.  In the Pacific Islands, this life force is called mana.  In the Star Wars universe, it's just called “The Force”. 

Now, if you look up vitalism on Wikipedia, you'll see a page that makes it sound like it was debunked hundreds of years ago, and no one sane believes it any more.  In fact, it might be this discord which drew you to the course in the first place.  The truth is, vitalism is alive and well – I know many many sane professional people (scientific folks, even), who embrace it and operate from the paradigm on a day to day basis.  Not just chiropractors, either.  :)

Before I get to combining vitalism and A&P, let's contrast vitalism with its opposite philosophy – mechanism.  Where vitalism says the whole is greater than the sum of its parts, mechanism says that the whole can be understood solely by understanding the parts. 

Where vitalism talks about the parts being integral to the whole, mechanism dismisses parts without hesitation.  That spleen?  You can do without it – take it out.  Appendix?  Accessory organ, unnecessary... you get the idea.  Vitalism assumes a higher intelligence at work, mechanism claims understanding.

Vitalism acknowledges an inborn intelligence ordering matter, mechanism says that no such intelligence exists, and thinks that our conscious minds can explain, comprehend, and create everything that we need to.

Western medicine is steeped in the hubris of mechanism.  Most alternative healing professions come from a more vitalistic perspective.

So Why pair vitalism and A&P? 
Virtually every A&P textbook I've ever seen is written from a mechanistic perspective.  The body is divided up into systems, and each system is studied individually.  To be fair, while discussing the cardiovascular system, the nervous system influence on the heart is mentioned, and ditto for the respiratory system and so on.  Unless we look at A&P from the perspective of vitalism, however, the millions of connections and interrelatedness of every tissue cell and organ in the body is missed, or at best, glossed over and one must study very hard pulling information from many sources and chapters to get a glimpse of the whole picture.

This course is designed for someone who has had some exposure to A&P.  I'm assuming that you have all had at least an introductory level anatomy and physiology class.  So while there are some basics that I will cover and review, they will be presented with an understanding that it is a review, not a new concept.  If you need further information about any of these subjects, refer to the references given at the end, and by all means ask questions.

I mentioned that this series was going to be divided into different functions rather than systems.  In order to do that, however, there is some basic underlying concepts that I need to cover first.  So the first module will review some terminology and some basic chemistry, biology, and physiology that we will continually reference as we go deeper in our studies.

This means that at least the first part of this module will feel a little more like the traditional things that have always been covered in A&P – bear with me – I promise it won't feel like a traditional class soon enough!

What is commonly called “Medical Terminology” is actually one of my favorite subjects.  It's fun because once you know meanings of things, you can create all sorts of fun words, and once you understand the pieces, you can pull apart those extraordinarily long words found in journals and textbooks and make sense of them.   Now, I'm not going to go into everything here – a quick online search will lead you to several free online medical terminology classes.  Even though they are divided up by systems (it makes more sense when studying the terminology than it does the function!), I recommend finding one that you can book mark and reference it when necessary.  I'm just going to give you a really brief overview of some of the important parts.

There are three basic puzzle pieces that are used – prefixes, root words (or RW's, which become combining forms (CF's)) and suffixes.  Prefixes are found at the beginning of the word, suffixes are at the end of the word, and in general, combining forms are in the middle.  Sometimes, you can make a word with just a prefix and a suffix together, but that's not typical.  A suffix and CF make a word, a prefix and CF make a word, a RW alone is a word, and sometimes prefixes and suffixes alone have their own meanings as well.  As we go through the modules, when I use terminology, I will often point out the different parts of the word, and tell you where they come from – this will help make the language that I'm using clear, but also help you remember the words and parts of words in the future, so when you see them in other forms, they'll have meaning for you.

The other thing that I love about terminology is that it's incredibly specific and precise.  Especially the directional terminology, So we're going to go over this first, because these are words that you will hear again and again, and not always words that can be picked apart to figure out the meaning. 

When you look at a map for the first time, what do you do before you do anything else most likely?  You either determine where north is, or where you are, right?  You find something on the map that you can use to orient yourself to what it is showing you.  If someone tells you to get to their house, you need to drive south and then their house will be on the left, you have to know what direction south is, correct?  (It helps to know what left is, as well!)

When referring to anatomy, there are certain standards that are used for directional terminology. 

The first is known as “Anatomical Position” - this is the starting point for ALL directional terms used when referring to the body.  If you stand up straight, have your feet hip width apart, your toes pointed forward, your arms relaxed down by your sides, your palms facing forward, and look straight ahead, you are in anatomical position.  In fact, do it right now.  Stand up next to your chair or wherever you're sitting, and assume the position!

Take a minute to notice how things are positioned – where are your pinkies in relation to your thumbs?  Where are your shoulders in relation to your hips?  We'll learn some specific terms for these relationships, but if you can remember this position, it will help you tremendously.  IT DOES NOT MATTER WHAT POSITION SOMEONE IS IN WHEN YOU ARE LOOKING AT THEM – IT IS THE POSITION OF LIMBS AND ORGANS IN ANATOMICAL POSITION ON THE PERSON THAT IS REFERENCED THAT IS USED TO DESCRIBE THE RELATIONSHIP.

Because of that standard, when one health care professional is talking to another, there is a common definition of superior, inferior, lateral, medial, etc.  The precise terminology allows for a common language, which (ideally) decreases errors and makes for consistency.  It doesn't matter if the patient in front of them is lying on their side or on their back, or if the practitioner is on their right side or left side.  Anatomical terminology will allow them to directly reference the same point on that person. 

The directional terminology that we'll cover today is:

Superior - above
Inferior - below
Cephelad (Cephalic) - towards the head
Caudad (Caudal) - towards the tail
Proximal - closer to  
Distal - further away from
Medial - towards the midline
Lateral - further away from the midline
Superficial - towards the surface of the body
Deep/Internal - below the surface
Prone- lying face down
Supine - lying face up
Pronation - commonly used for the hands, palms down
Supination - again, commonly used for the hands - palms up (think holding a bowl of soup (sup)
Inversion - commonly used describing the feet - turning the sole of the foot inwards (sometimes refered to as supination, even with the feet)
Eversion - again, for the feet, turning the sole of the foot outwards (over-pronation)
Abduction - moving a limb away from the midline
Adduction - moving a limb towards the midline
Flexion - making a joint angle
Extension - making a joint angle larger
Dorsal - the back of the body
Ventral - the front/belly of the body
Anterior - the forward part of the body
Posterior - the back part of the body
Transverse plane - divides the body into inferior and superior segements
Frontal/Coronal plane - divides the body into anterior and posterior segments
Oblique plane - divides the body at an angle
Sagital plane - divides the body into right and left segments
Midsagital/Median plane - divides the body evenly into right and left halves

It's important to note that some of these terms are synonymous on humans because of anatomical position - ventral and anterior, dorsal and posterior, superior and cephelad, inferior and caudad for example.  In dogs, ventral and inferior are synonymous, and anterior and cephelad are as well.  

As we go through the different modules, we'll be adding to the terminology list, but these are terms that regardless of subject matter, you'll hear and you should be familiar with.

Some basics of Chemistry and Biology:  Atoms, Elements and Ions – oh my!

Remember the periodic table of the elements?  Yeah, me too.  Don't worry, you don't have to quote it or memorize it, or even know which column is noble gasses (although strangely, I do remember that even though I've never used it outside of the chemistry lab!).

What you want to understand about chemistry is this:

Atoms are the building blocks of everything that you see, they are composed of protons, neutrons, and electrons.  Protons have a positive charge, neutrons are neutral, and electrons are negatively charged particles.  As we progress, typically the thing that we'll be most concerned about are electrons when we talk about chemical interactions.  The center of the atom is called the nucleus, and it is where the protons and the neutrons are stored.  The electrons circle the nucleus, much like planets orbit around the sun.  An atom is neutrally charged, because it has the same number of protons and electrons.   You don't need to know about how the atom appears in an atomic drawing, or what the electron clouds look like – if you want to pick up a basic chemistry book and review this, you're welcome to, but it won't be covered here.

(That periodic table that you remember?  It lists all the different types of atoms known to us at this time.  They are organized according to different properties that the the elements have in common given a similar structure.  And while atom = element is not entirely true, for our purposes, at this time, you can think of them that way.  An element is the smallest thing that you can have and still have gold, for example.)

Atoms join together to form molecules.  And molecules can join together to form compound molecules.  Some molecules, in turn, break into ions when they are dissolved.    Ions are charged particles of an element.  When a molecule breaks apart, sometimes the ion will have a few more electrons than it did before – if that's the case, the ion is negatively charged and called and anion.  If it has less electrons than protons, it is positively charged and is called a cation.   Cl- is a chloride ion – it has one more electron than proton, so it is negatively charged.  Mg2+ is a magnesium ion – it has two less electrons than protons, so it has a 2+ charge.

You should know about a few different types of molecules.   Most of them should be familiar to you, so we'll quickly go over the definitions so we can get on to the more fun stuff:

Water (hydrophilic/hydrophobic)
Nucleic Acids
ATP (and other high energy compounds)

Just a few other important concepts and we can leave chemistry behind.

Solution vs. Colloid vs. Suspension
Concentration, Osmosis, Diffusion

That's it – we just covered the extent of the basic chemistry knowledge.  So if the thought of revisiting chemistry had you sweating and hyperventilating, relax, sit back down, and let's move on to some biology basics. 

Biology and Anatomy & Physiology
(Note: A lot of what is covered in a basic biology course will not be covered here, because it is not relevant to what we are talking about.)

When you get enough of the right molecules together, in the right manner, you can form some really important biological building blocks.  DNA, cell organelles, cells... and eventually tissues and organs and organisms!

The Cell
Cells are typically thought of as the building blocks of life.  The simplest creatures are one celled organisms (aka unicellular) like protozoa and bacteria.  Our bodies are made up of trillions of these tiny building blocks.  Inside cells, are smaller structures called organelles, which help the cell perform the functions that it is required to perform.  Anytime you see the suffix -elle, think “little” of whatever the rest of the word is – so organ-elles = little organs.  As necessary, we will cover the specific organelles in more detail, but for now, here's a brief reminder of the organelles that are most common:

Cell membrane/Plasma membrane – in some cases, it has a different name, but it is the cell membrane which separates the inside of the cell from the outside of the cell.

Cytosol/Intracellular fluid/Cytoplasm – all these words refer to the fluid inside of the cell, the rest of the organelles are floating freely or are anchored in some way inside this fluid.

Nucleus – The nucleus is where the DNA is found – the blueprint for life.  A cell may have one of these (uninucleate), or many (multinucleate).  Although there are cells without nuclei (called prokaryotic cells), they are not part of the human body per se (we'll talk more about the human biome at various points, especially when discussing digestion, and we'll cover a little bit about them at that time).  The nucleus (and its contents) are separated from the rest of the cell by the Nuclear Envelope.  The fluid inside the nucleus is sometimes called the nucleoplasm. 

Nucleolus -  a structure that is found within the nucleus composed of proteins and nucleic acids.  We'll talk more about the inner workings of the nucleus at another point.

Endoplasmic Reticulum – There are two types of ER – smooth ER, which lacks ribosomes, and rough ER, which has them.  You can think of the ER as the manufacturing plant of the cells – it is here were protein synthesis, lipid synthesis, and the production of other important things usually takes place.

Lysosomes – these are free floating bags of enzymes that break down waste products or things not needed in the cell.

Mitochondria – the energy powerhouses of the cell – the Krebs cycle occurs inside these tiny structures, and is the primary source of energy within the cell.

Centromeres – organelles that are active during cell division.

Golgi Apparatus – creates some molecules, but functions more for packaging secretions to be released outside of the cell.

There are a few other organelles, and in many cases these organelles are modified in certain cells (and sometimes renamed – oy!) to perform whatever function that cell must perform.

We'll cover the modifications and more specifically the function of the individual organelles as we talk about different body functions. 

Tissues and Organs
A tissue is defined as two or more types of cells collaborating to perform a specific function.  There are four general tissue classifications:  Epithelial, Connective, Muscle, and Nerve. 

Each tissue is specially designed to perform a specific function.  Epithelial tissues are found covering and lining, Connective tissues support other tissues, Muscle tissue allows for movement, and Nerve tissue allows for long distance communication.  We'll discuss individual tissues as we need to cover them.  Remember that even on a microscopic level, there is a relationship between what something looks like and the job that it does. 

Organs are defined as two or more tissue types working together to perform a specific function (or functions). 

Systems are defined as two or more organs working together to perform a specific function or functions.

You may hear of “levels of organization” - from small to large, as relevant to A&P, they are:
Chemical level (atoms and molecules)
Cellular level (organelles and cells)
Tissue level (tissues)
Organ level
Organ System level
Organism level

For much of what we'll cover, we'll do some bouncing from level to level, so it's helpful to remember where you're at as far as levels of organization.  I'll be as clear as I can, especially when I jump from level to level!

Anatomy is the study of where things are in the body.  Anatomy answers the question “What is that?”

Physiology is the study of function – it answers the question “How does this work?”

They are often viewed together initially (like in the intro A&P class), and then when covered in more depth, separated.  However, they are connected, and you can't really study one without the other.  The term complementarity is often used to describe this relationship. 

As we go through different concepts, one that links everything together is simple to remember:


Why is something located where it is?  Why is it connected to that?  Why is it shaped like that?  Why does it produce that?  If you can start asking, and answering, these questions, you'll find that a lot of A&P is quite intuitive – the stomach is shaped like a bag with ties on either end so that it can mix up the stuff that comes into it with the juices it produces.  Even on a microscopic level, the question of “What does that do?” can often be answered by understanding what it looks like.  The walls of the alveoli, in the lungs are made up of a single layer of flat cells, ideal for gas exchange to occur across them. 

Wolff's law:  Form follows function, and function follows form.  A great rule to remember as you learn. 

If you can start asking and answering the why question, you'll have an easier time putting the pieces together!

A few last concepts, and then we're done with the review of the basics, and we can move onto other things.

In order to maintain life, there are things that an organism (and we'll be talking specifically about humans) must do.  There are also things that are required in our environment.

The things that we must do can be termed necessary life functions.  We've already covered some of the things on this list – and mentioned that they will serve as the focus for future chapters.  Some of them, such as responsiveness and metabolism, are too extensive to be covered in any one module, and will be covered as they apply to the more specific functions. 
            Maintain boundaries - separate self from not self
            Movement - get from point a to point b, and have things move around internally
            Responsiveness or Irritability - detect external environment and changes, and respond appropriately to them
            Digestion - bring in nutrients from outside the body, process them to a usable state, and get them where they are needed
            Metabolism - all of the chemical reactions that take place in the body
            Excretion - getting rid of waste products
            Reproduction - making new life

The environmental requirements are things that must exist in our environment to allow life to be sustained.  They include:
            Nutrients - we cannot make our own food - we need food from outside the body
            Appropriate Temperature
            Appropriate Atmospheric Pressure

No comments:

Post a Comment