Hi. So today, we're going to introduce the human body and we're gonna do this
by basically just doing a general overview of anatomy and physiology,
and then from there in the subsequent lectures,
we will go a little bit more in detail about the different organ systems.
So first off, let's talk about anatomy and physiology.
When we talk about it, we normally use the two words together but they are actually two separate disciplines.
Anatomy is gonna be the study of the structures of the body whereas physiology
is going to be the study of how those body parts are actually functioning.
So here you have a table that just shows you the differences
between the branches of anatomy and the branches of physiology.
For example, a radiologist or someone who's going to study things like X-rays
and look at images of the structures of the body would actually be studying the branch under anatomy
whereas let's say, a cardiologist or a neurologist is going to be really studying the physiology
and specifically the pathophysiology when making diagnosis.
So now let's just talk about the human body and the way that it is organized.
So when we see -- we visualize the human body, let's think about that as like a book.
And so we start at the most basic level of any book or in -- is going to be the letters in the book.
So in this way, we have the chemical level.
The chemical level is going to be made up of your atoms and your molecules.
These are the most basic structures of the human body. From there, we have our words.
So the words in the book are now the most functional part of the book.
So when you just have letters, if you just threw a whole bunch of letters onto a page,
they wouldn't make sense but once you put those letters into functional units known as words,
now we are able to actually start doing things.
This is the same when we talk about the cellular level.
The body is made up of trillions of cells and these cells are the basic functional unit of the human body.
When we take a group of cells and we put them all together, we get the tissue level.
So a group of similar cells working together are going to make tissues in the body
and there are several different types of tissues found in the human body.
And so the tissue level would be like in a book, taking those words and putting them into sentences.
So then we take our sentence and we're gonna take multiple sentences, put them together, and make a paragraph.
This would be similar to your organ level.
So at the organ level, now we're gonna take different types of tissues
and we're gonna put them all together in order to perform some type of function.
And that's when we get our different organs.
So examples of organs are gonna be things like the heart, the stomach, the eyes, the nerves, and the neurons.
All of these things are different types of organs.
And then from there, we take our paragraph and we put that into chapters.
So a chapter is usually about one specific subject and then the same way,
our organ systems or the system level is when you have a group of organs
working together to perform a function.
So an example of a system would be like the digestive system
which is involved in the digestion of the nutrients that we take in from our external environment
and how our body uses those nutrients. And so finally, we get our book.
The book is the organism or the organismal level where we're taking all of the chapters,
we put them together, and we make our story. The story of the body.
So let's now talk about things from the system level.