Hi. In this lesson, we'll be talking about the musculoskeletal system, which is made up of the muscle system and the skeleton. Now the muscle system is an organ system that is made up of muscle, and it's going to include skeletal, cardiac, and smooth muscle, which are different types of muscle. Muscle is just a tissue that can contract due to an interaction between actin and myosin that we'll take a closer look at later. Muscle cells are called myocytes, and that prefix "myo" generally refers to muscles. Now there are specialized types of myocytes that you'll find in skeletal, cardiac, and smooth muscle, but you don't need to worry about that just yet.
Now, here we have a nice overview of the human muscle system, and here we can see just a few individual muscles, and how they are connected to bones. Behind me here, we have a myocyte. This is a muscle cell, and you might notice that there is a nerve that is forming a connection with it. We'll talk more about why that is later. Now the skeleton is going to be the support structure of an organism and it's going to work with the muscles to produce locomotion. Some organisms have an external skeleton called an exoskeleton. This is common in arthropods, like this awesome rhinoceros beetle you see here. We humans, on the other hand, have an endoskeleton, which you can see here. And this is an internal skeleton that's going to be made up of mineralized tissues, like bone. Bone is this rigid mineralized organ we'll talk a little bit more about later. And muscles and bones are going to be connected to allow for voluntary movement. We call this movement locomotion. You can see a pretty awesome example of that in this cheetah right here behind me.
With that, let's go ahead and flip the page.
