Module 1
1. Module 1
1.12. Page 5
Module 1—The Nervous System
Lesson Summary
In this lesson you have explored the following focusing questions:
- What are the main structures of the brain and spinal cord, what are their functions, and how are these functions co-ordinated?
- What happens when the information to or from the brain or spinal cord is disrupted or interrupted?
You have examined how all information about the external and internal environment is sent to the central nervous system, which consists of the brain and the spinal cord. Various part of the brain, including the cerebral hemispheres, the four lobes of the cerebrum, the cerebellum, the medulla oblongata, the pons, and hypothalamus, are responsible for receiving, sorting, interpreting, and co-ordinating information. The central nervous system (CNS) also initiates action in either the somatic or autonomic nervous system.
The spinal cord functions to receive sensory information via the sensory neurons in the dorsal root and either relays the messages to the brain or initiates an action through a motor neuron in the ventral root. In Lesson 3 you will learn about these neurons and the reflex arc, a major function of the spinal cord.
The destruction of the insulating layer around the neurons in the central nervous system (CNS) and peripheral nervous system (PNS) results in nerve impulses not being transmitted quickly enough or not being transmitted at all. This disorder is known as multiple sclerosis (MS). Muscle response becomes sporadic and eventually ceases. As you work through this module, you will understand the cause and symptoms of MS.
Lesson Glossary
Consult the glossary in the textbook for other definitions that you may need to complete your work.
occipital lobe: one of the four lobes of the cerebrum that receives and analyzes visual information that is sent to association centres for recognition of what is being seen