1. Objective: to describe the general characteristics of and functions of nervous tissue

2. 1. Found in the brain, spinal cord, and nerves 2. Contains specialized cells called neurons, which transmit nerve (electrical) impulses 3. Functions: a. Regulates & controls body functions b. Generates & transmits nerve impulses (electrochemical) c. Supports, insulates and protects impulse generating neurons.

3. Has 3 Parts: 1. dendrite- collects signals that may result in a nerve impulse 2. cell body- contains the nucleus and most of the cytoplasm 3. axon- conducts nerve impulses

4. 1. Branching cells with many long processes 2. Large central nucleus 3. Transmit impulses from one area of the body to other areas 4. Regulate activities through neuron impulses 5. Myelin = fatty material covering axons of neurons

5. 1. Long axons bound together by connective tissue 2. Conduct impulses from sense organs to the brain and spinal cord- -- call this phenomenon sensation 3. Conduct nerve impulses away from the spinal cord and brain to the muscles, causing the muscles to contract

6. 1. These cells outnumber neurons 9 to 1 in the body and take up more than half the volume of the brain 2. Function = to support and nourish the neurons 3. Schwann cells- encircle all long nerve fibers found outside of the brain or spinal cord; do this in small sections 4. Gaps between Schwann cells are called “nodes of Ranvier”

7. 5. Collectively, Schwann cells provide nerve cells with their myelin sheath, which speeds up nerve conduction because the impulses jump from node to node