Adipose tissue, or fat, is a specialized connective tissue -- the material inside your body that supports many of its parts. Adipose tissue is primarily located directly below the skin, but it also surrounds internal organs. In the skin, adipose tissue provides insulation from heat and cold. Adipose tissue is also important in storing energy in the form of fat. In animals, obesity or excessive fat accumulation is not dependent on the body weight, but on the amount fat deposited in the body -- specifically adipose tissue.
In mammals, two different types of adipose tissue exist -- white adipose tissue and brown adipose tissue. White adipose are the most common type of tissues and serve as energy store for times of starvation. They also form pads between organs. Brown adipose tissue is found mainly in newborn animals. Brown adipose tissue plays an important role in the survival of some animals, particularly those that hibernate -- to pass the winters in inactive state. Hibernating species experience a drop in body temperature during winters. Brown adipose tissue, by consuming energy, releases heat, which is vital for hibernating animals.
Nervous tissue is composed of neurons and glial cells. Neurons, the cells that constitute the brain, spinal column, and nerves, are variable in shape and size. A typical neuron consists of a cell body which contains the nucleus, dendrites -- short fibers extending from the cell body, and axon, a single long fiber. Glial cells provide support and protection to the neurons.
Neurons are highly specialized for the transmission of information throughout the body. Neurons are responsible for communicating information in both chemical and electrical form. Glial cells regulate the internal environment of the brain, especially the fluid surrounding the neurons.