The Nervous System

Table of Contents

1. Introduction to the Nervous System
2. Parts of the Nervous System
3. The Brain
4. Brain Fun Facts
5. Parts of the Brain and their Basic Functions
6. The Spinal Cord
7. Nerves
8. Parts of a Nerve and their Basic Functions
9. Other Systems that Interact with the Nervous System

Parts of the Nervous System

The nervous system includes:

• The Brain
• The Spinal Cord
• Nerves

The Brain

The brain is the command center of the nervous system and is critical to survival. Vision, movement, the beating of your heart and lungs, and everything else your body does is controlled by your brain. Every part of your brain has a different function and most are needed to survive.

Brain Fun Facts

• The brain weighs about 3 pounds
• The brain makes up about 2% of your weight
• The cerebrum makes up 85 percent of the brain’s weight.
• The brain contains about 86 billion nerve cells
• The brain is made of 60% fat

The Spinal Cord

The spinal cord is a critical part of the nervous system. It sends messages between your brain and the rest of your body. The spinal cord is made of nervous tissue in a long tubular structure. Nerves from all over your body connect to your spinal cord to send information up to your rain like touch and pain. Your brain then causes you to feel that sensation and recoil if needed. As shown in the diagram the nerves are encased in the vertebrae to protect them.

Nerves

All people can feel when they touch something, and this is because of your nerves. Your nerves run all throughout your body and inform your brain of what is touching you and if it should inflict pain. Nerves also send messages to all your other body systems to tell them what to do.

Parts of a Nerve and their Basic Functions

The parts of a nerve cell include:

• The soma/ cell body: Holds all the normal cell parts
• Nucleus: Contains DNA
• Dendrites: Receives messages from other cells
• Axon: Sends messages
• Myelin sheath: Protects axon
• Axon ending: converts the electrochemical message into a chemical message so it can be sent to the next nerve
• Synapse: The gap between nerves

Essential Questions

• How are structures in the body organized?

Structures in the body are organized into many different systems, all of which work together to support life.

• How are structures in a CELL organized?

Structures in a cell are organized into different parts that each play a different role in keeping your body alive.

• How are the structures in your chosen BODY SYSTEM organized?

Structures in my chosen body system are organized into the brain, nerves, and the spinal cord. They all work together to help your body function.

• How do these structures work together to support life?

These structures work together to support life by removing waste, taking energy from food and everything else your body needs to do to survive.

• How do CELL PARTS work to meet the needs of the CELL?

Cell parts work to meet the needs of the cell by helping it copy itself and providing it with energy.

• How do CELLs work together to form BODY SYSTEMS?

Cells work together to form body systems by following the instructions in their DNA to make certain structures.

• How does your chosen BODY SYSTEM work?

My chosen body system works by sending messages trough nerves and the spinal cord to your brain which tells your body how to react. The brain also controls your heart, lungs, and other involuntary things your body does.

• How do BODY SYSTEMS work together to support the needs of a whole organism?

Body systems work together to support the needs of a whole organism by doing everything your body needs to survive.