Chapter 8

Nervous System

The Nervous System examines the structures and functions of the entire nervous system. The book contains 84 pages that thoroughly depict the cerebral cortex, the spinal cord, autonomic nervous system, and its branches. The nervous system is divided into two parts, the CNS and the PNS. The CNS is the central nervous system. The PNS is the peripheral nervous sysem, which is further divided.

Nervous system

All multicellular organisms have a nervous system, which is an assemblage of cells sorted by their shape and function and act as the major coordinating organ of the body. Nervous tissue underlies the ability to sense the environment, to move and react to stimuli, and to generate and control all behavior of the organism. Compared to vertebrate nervous systems, invertebrate systems are somewhat simpler and can be easier to analyze. Invertebrate nerve cells tend to be much larger and fewer in number than those of vertebrates. They are also easily accessible and less complex. However, the rules governing the structure, chemistry, organization, and function of nervous tissue have been strongly conserved. Therefore, although humans and the higher vertebrates have unique behavioral and intellectual capabilities, the underlying physical-chemical principles of nerve cell activity and the strategies for organizing higher nervous systems are already present in the lower forms.

Central Nervous System

The central nervous system (CNS) is composed of the brain and spinal cord. The brain receives sensory information from the nerves that pass through the spinal cord, as well as other nerves such as those from sensory organs involved in sight and smell. Once received, the brain processes the sensory signals and initiates responses. The spinal cord is the principle route for the passage of sensory information to and from the brain.

Information flows to the central nervous system from the peripheral nervous system, which senses signals from the environment outside the body and from the internal environment. The brain's responses to incoming information flow through the spinal cord nerve network to the various effector organs and tissue regions where the responsive action will take place.

Dangers

Alzheimer Disease

Spinal Cord injuries

Parkinson’s

Other diseases

Impairment

Types of Nerves

· Cranial Nerves (attached to brain)

· Spinal Nerves (attached to spinal cord)

~Types of Neurons~

· Motor neurons

· Sensory neurons

· Interneurons

Parts of the Brain

Cerebrum

Diencephalon

Cerebellum

Brain Stem