The Nervous System

1. The Nervous System The Brain

2. Central Nervous System Composed of the brain and spinalcord

3. Layers of the brain The cranium The brain is protected by a bony covering called the cranium (which, along with the bones of the face, make up the skull). Inside the cranium, the brain is surrounded by the meninges. Meninges are membranes that cover the CNS. Their primary function, along with the cerebrospinal fluid is protection.

4. Layers of the brain: greymatter The cerebralcortexcovers the outer portion (1.5mm to 5mm) of the cerebrum. It is the layer of the brain often referred to as gray matter. The cortex (thin layer of tissue) is gray because nerves in this area lack the insulation that makes most other parts of the brain appear to be white. The cortex also covers the cerebellum.

5. Layers of the brain: whitematter White matter consists mostly of glial cells and myelinated axons that transmit signals from one region of the cerebrum to another and between the cerebrum and lower brain centers. Glial cells are non-neuronal cells that maintain homeostasis, form myelin, and provide support and protection for neurons in the brain and peripheral nervous system.

6. The brain isdivided in right and lefthemisphere connected by the corpus callosum The corpus callosum is a bundle of neural fibers deep in the center of the brain. The corpus callosum connects the left and right cerebral hemispheres to provide communication between the two sides of the brain.

7. The brain is made up of 3 parts The forebrain: cerebrum, thalamus and hypothalamus (part of the limbicsystem The midbrain (mesocephalon) The hindbrain: the cerebellum, pons and medulla. Alsoknownas the brain stem.