Central Nervous System

Central Nervous System

After studying this chapter, readers should be able to:

1. Name the primary regions of the brain in adults.

2. Describe the locations of the ventricles of the brain.

3. Describe the gyri, sulci, and fissures of the brain.

4. Explain the part of the brain that is connected to pituitary gland.

5. Describe the functions of the hypothalamus and thalamus.

6. Describe the centers that control blood pressure and respiration.

7. Specify the functions of the cerebellum.

8. Explain the layers of the meninges.

9. Discuss the main structures and functions of the spinal cord.

10. Describe the effects of the aging process on the brain.

Overview

The brain and spinal cord make up the central nervous system (CNS). The brain is the largest and most complex portion of the nervous system. It controls perception, movement, sensation, thinking, and many other physiological aspects. The sections of the brain include two cerebral hemispheres, the diencephalon, the brain stem, and the cerebellum. There are approximately 100 billion multipolar neu-rons in the brain as well as axonal branches that allow these neurons to communicate throughout the nervous system.

The brain and spinal cord are connected via the brain stem, which allows communication to flow in both directions. The spinal cord also provides a two-way communication, between the CNS and peripheral­ nervous system (PNS) . The organs of the CNS are surrounded­ by bones, fluid, and membranes. The brain lies within the cranial cavity of the skull. The spinal cord lies within the vertebral canal, inside the vertebral column. Under the bony vertebrae are the ­membranes called meninges. They are located between the vertebrae­ and soft tissues of the nervous system and protect both the brain and spinal cord.