 Here everybody, Dr. O here. So we've so far talked about atoms and molecules coming together to form organelles and cells and the cell is the basic unit of life. But for the human body to work correctly, our cells have to work together and that's where tissues are going to come into play. So a tissue is when you take a group of specialized cells that have a specific function. The study of these tissues is going to be called histology. So later we'll see how when you put tissues together you form organs and organ systems and the whole human organism. So in this video we're going to talk about the four basic types of tissues and you'll see them kind of in order of importance. This chapter we have epithelial tissue, connective tissue, muscle tissue and neuro tissue. So muscle tissue and neuro tissue we're barely going to talk about in this chapter because they have their own chapters later. And then I'm going to come back and cover connected tissue at the end because it's such a catch all basically how I think of it is if it's not one of the other three then it falls into the category of being of connected tissue. Let's start by talking about epithelial tissue. So the words I think of here are linings and coverings and surfaces. So any surface of the body like your skin is going to be lined with epithelial tissue. And then any part of your body that's exposed to the external environment which you think skin but also think your GI tract from your mouth to your anus, your respiratory tract, your genital urinary tract, your reproductive tract, those are all exposed to the external environment. So they're going to be lined with epithelial tissue. But then we have internal services as well. The lining of your blood vessels, the lining of the inside of your heart, the pericardial cavity your heart is in, the pleural cavity your lungs are in. These are all examples of surfaces, linings and coverings. So those are going to be epithelial tissue. So like I said, I'll come back to connect tissue in just a moment. So muscle tissue pretty straightforward, it's job, it's specialized for contraction. So the tissue that contracts in your body is going to be muscle tissue. You'll see the three types. We have cardiac muscle that's in your heart, smooth muscle, lines, hollow organs, and then skeletal muscles, the muscle we think of with voluntary control that moves our body. Neurotissue or nervous tissue, it's job is to send and receive electrical impulses. So you see the brain, spinal cord and nerves there, we'll cover that in great detail. So if it's not lining or covering something, it's not contracting and it's not sending and receiving electrical impulses, then it falls into our fourth category, this catch all called connective tissue. So we'll cover what it means to be connective tissue later. I mean all sorts of things, you see fat, bone, tendon, these are all examples of connective tissue. We have fluid connected tissues like blood and lymph. So you see a wide category like what is fat and lymph and a tendon or a ligament have to do with each other, well, they're all connective tissue. So I'll make sense of all that later. So those are going to be the four basic tissue types of the body. Welcome to Astrology. I hope this helps. Have a wonderful day, be blessed.