The spiny lizards are medium to large lizards up to 10 inches long. They have keeled, pointed scales that are usually a subdued gray or tan, a wide purple stripe down the back and scattered turquoise scales mixed with tan and brown on the back and sides.he lizards grow out of their skins and usually shed in patches rather than in one piece like a snake. The spiny lizards eat insects, other lizards, and some plant material such as leaves, berries, and flowers. They are preyed upon by snakes, coyotes, and birds of prey.
Cells of nervous tissue. Nervous tissue is the main component of the two parts of the nervous system; the brain and spinal cord of the central nervous system (CNS), and the branching peripheral nerves of the peripheral nervous system (PNS), which regulates and controls bodily functions and activity.ells of nervous tissue. Nervous tissue is the main component of the two parts of the nervous system; the brain and spinal cord of the central nervous system (CNS), and the branching peripheral nerves of the peripheral nervous system (PNS), which regulates and controls bodily functions and activity.
Nerve Tissue. Although the nervous system is very complex, there are only two main types of cells in nerve tissue. The actual nerve cell is the neuron. It is the conducting cell that transmits impulses and the structural unit of the nervous system. The other type of cell is neuroglia, or glial, cell.The word neuroglia means nerve glue.. These cells are nonconductive and provide a support system for the neurons. They are a special type of connective tissue for the nervous system.he unmyelinated regions between the myelin segments are called the nodes of Ranvier. In the peripheral nervous system, the myelin is produced by Schwann cells. The cytoplasm, nucleus, and outer cell membrane of the Schwann cell form a tight covering around the myelin and around the axon itself at the nodes of Ranvier.