What are tissues and organs? Lesson 1 What are tissues and organs?

A car has many parts. Each part does a special job A car has many parts. Each part does a special job. All the parts must work together to keep the car running well. The engine purrs perfectly. The transmission works just fine.

However, your chassis has a huge crack in it. Are you comfortable taking a long ride in the car?

In some ways, your body is like a car. It is made of many parts In some ways, your body is like a car. It is made of many parts. These parts work together to keep you running well. As you know, your body is made of trillions of cells. These cells are alike in certain ways.

The cells in your body are not all the same The cells in your body are not all the same. They have different sizes and shapes. Different kinds of cells have different jobs to do. Specialized cells are similar in size and shape. Their size and shape help them do their job .

The job of a specialized cell can be done only by that kind of cell. A nerve cell is the only cell that can send and receive messages. A muscle cell is the only cell that can make bones move.

In many-celled organisms, cells work as teams, much like a baseball team. They form specialized groups of cells called tissues.

A tissue is a group of similar cells that work together to perform a specific function.

There are 4 main kinds of tissues in the human body. They are: Muscle Epithelial Nerve Connective

Each of those tissues has a very specific kind of job to do. Epithelial Tissue- Is covering tissue. The cells are joined tightly together. Skin is epithelial tissue, as is the tissue that covers and protects your internal organs.

Nerve Tissue- Is made up of nerve cells. It sends and receives messages. It allows us to respond to stimuli inside and outside of our bodies.

Connective Tissue- Supports the body and holds it together. Bone, cartilage, tendons and ligaments are connective tissue Blood is the only liquid connective tissue.

Muscle Tissue- Makes movement possible. It is made of cells that can become shorter. There are different kinds of muscle tissue. Some are attached to bones

Organs Groups of tissues that group together to do a job are called organs. There are many, many organs in your body.

Heart- Your heart pumps blood throughout your body. It is made mostly of muscle tissue. Stomach- Digests food. It is made of muscle, nerve and blood tissues.

Skin- Covers and protects the body. It helps get rid of salts, water, and heat. It also prevents the loss of body fluids. It is made mostly of epithelial tissue

Brain and spinal cord- The brain is the organ of thinking; the brain and spinal cord send and receive messages. They are made of mostly nerve tissue.

Ears, eyes, nose, tongue and skin- Are sense organs. They tell you what is happening around you. They are made of nerve, muscle, blood and other tissues