Adipose tissue is a loose connective tissue composed mostly of adipocytes. It also contains the stromal vascular fraction (SVF) of cells including preadipocytes, fibroblasts, vascular endothelial cells and a variety of immune cells such as adipose tissue macrophages. Its main role is to store energy in the form of lipids, although it also cushions and insulates the body.
Pig belly fat (white)
The obese mouse on the left has large stores of adipose tissue. It is unable to produce the hormone leptin. This causes the mouse to be hungry and eat more, which results in obesity. For comparison, a mouse with a normal amount of adipose tissue is shown on the right.
Abdominal obesity in a man ("beer belly")
Brown fat cell
Connective tissue is one of the four primary types of animal tissue, along with epithelial tissue, muscle tissue, and nervous tissue. It develops mostly from the mesenchyme, derived from the mesoderm, the middle embryonic germ layer. Connective tissue is found in between other tissues everywhere in the body, including the nervous system. The three meninges, membranes that envelop the brain and spinal cord, are composed of connective tissue. Most types of connective tissue consists of three main components: elastic and collagen fibers, ground substance, and cells. Blood, and lymph are classed as specialized fluid connective tissues that do not contain fiber. All are immersed in the body water. The cells of connective tissue include fibroblasts, adipocytes, macrophages, mast cells and leukocytes.
Section of epididymis. Connective tissue (blue) is seen supporting the epithelium (purple)
Hypermobility as a result of an inherited connective tissue defect.