Every cell in your body has a special specialisation that is related to maintaining homeostasis. When groups of cells with the same specialisation or function come together they form a tissue. In other words, the type of cells defines the type of tissue. There are four main types of tissue in the human body:
- Nervous Tissue – This type provides control and communication
- Muscle Tissue – This type allows for movement
- Epithelial Tissue – This type covers and protects out body
- Connective Tissue – This type provides support
Nervous tissue is found in the nervous system and is made up of unique specialized cells. Like electrical circuits, the nervous system transmits signals from nerves to the spinal cord and brain. Cells known as neurons conduct these impulses, making it possible for us to use our senses.
Muscle tissue is made up of excitable cells that are long and fibrous. These cells are able to contract (unlike the other types) which is the increased tension in muscles. They are arranged in parallel lines and are bundled, making muscle tissue very strong. If you take a pile of rubber bands, line them up next to each other and attempt to stretch them, you may get the idea of the nature of the muscle tissue.
Epithelial tissue is made up of epithelial cells. These cells can be flat, cuboidal, or columnar. They are joined tightly together, making a single or stacked continuous sheet. Like a quilt that is tightly stitched, epithelium makes an excellent protective cover for the body, in the form of skin. Epithelial tissue can also be found lining some internal cavities and organs.
As its name suggests, connective tissue makes up a connective web inside our body. Holding our body parts together and providing support are the main jobs of this tissue. We would certainly not be in good shape if all of our internal body parts were free-floating. Connective tissue fills in the spaces inside our body with a matrix made of fibres within a liquid, solid, or jelly like substance. Think of a gelatin salad with fruit suspended inside, and you will have an idea of how certain types of connective tissue function.
You already know many examples of tissue found in the body. Muscle tissue is found in all of the obvious places, as in our biceps, triceps, quadriceps and so on. But muscle is also located in many of our internal organs, such as the walls of our arteries and digestive tract. And don’t forget about the most important muscle of all: the heart. Cardiac tissue is also muscle tissue, as this powerful organ is constantly contracting to pump blood throughout our body.
Epithelial tissue, as previously mentioned, is found both covering our body and lining some organs. For example, our outer layer of skin is made of epithelial tissue. This sheet of epithelial tissue is like a permanent waterproof coat for our body. It protects us from potential invaders like viruses and keeps our body from losing moisture. The lining of the mouth and oesophagus are also examples of epithelial tissue.
Connective tissue comes in several different forms. The most abundant in the body is loose connective tissue, and it is found filling the spaces in our body. For example, if you pull on your skin it will stretch, but only so far. The connective tissue underneath it keeps it attached so that our skin isn’t flopping around. Fat tissue is another example of connective tissue, as it provides cushioning and support.
Finally, nervous tissue is clearly found within the nervous system. Neurons extend throughout the body, making it possible for us to use our five senses. The brain and spinal cord make up the rest of this type of tissue.