1. Homeostasis is defined as the body's internal environment being within a certain physiological state. There are seven major factors that need to be homeostaticly maintained. They are: concentration of oxygen and carbon dioxide, nutrition of cells, concentration of wastes, concentration of sugars, salts, and other electrolytes, temperature, and volume and pressure. An example of the body maintaining homeostasis is blood pressure. When the hear begins to pump faster, it sends more blood into the arteries which increases blood pressure. Pressure sensitive nerve cells detect the higher pressure and respond by sending the brain nerve impulses. The brain then sends impulses to the heart and certain blood vessels to slow the heart rate. If any of the seven factors and not correctly maintained, illness or death may occur.
             2. Tissues are groups of cells and intercellular substances that function together to perform specialized activities. There are four major types of tissue. Epithelial, connective, muscle, and nervous tissue. Each of these tissues performs a different function. Nervous tissue is responsible for initiating and transmitting nerve impulses that coordinate body activity. Muscle tissue is simply responsible for movement. Epithelial tissue forms glands, lines body cavities, hollow organs, and ducts. It also covers body surfaces. Connective tissue protects and supports the body and its organs. It binds organs together, stores fat and energy, and provides immunity. Connective tissue is also the most abundant tissue in the body for these reasons.
             3. Both shape and arrangement of layers of cells can classify epithelial tissues. There are four basic shapes of connective tissue cells. Squamous cells are flat and connect to each other like tiles. Cuboidal cells are thicker and can be described as cubed or hexagonal shape. Columnar cells are cylindrical and tall. Transitional cells range in shape. They can ch...