This chapter describes neurons and other cells of the nervous system and compares and contrasts divisions of the nervous system, including central, peripheral, somatic, and autonomic divisions. The chapter explains how nerve impulses occur and how we sense stimuli. It also describes disorders of the nervous system and the effects of psychoactive drugs on the nervous system.
- 11.1: Case Study - The Control Center of Your Body
- Each of these brightly-colored sticky notes represents a piece of information that someone doesn't want to forget. Although we are all forgetful sometimes, most people do not have trouble remembering things that are important or routine to us, such as our friend's name or how to get to class.
- 11.2: Introduction to the Nervous System
- The nervous system is the human organ system that coordinates all of the body's voluntary and involuntary actions by transmitting electrical signals to and from different parts of the body. Specifically, the nervous system extracts information from the internal and external environments using sensory receptors. It then usually sends signals encoding this information to the brain, which processes the information to determine an appropriate response.
- 11.3: Neurons and Glial Cells
- Neurons, also called nerve cells, are electrically excitable cells that are the main functional units of the nervous system. Their function is to transmit nerve impulses. They are the only type of human cells that can carry out this function.
- 11.4: Nerve Impulses
- This amazing cloud-to-surface lightning occurred when a difference in electrical charge built up in a cloud relative to the ground.
- 11.5: Central Nervous System
- This very odd-looking drawing is called a homunculus. The greenish mass represents a cross-sectional wedge of the human brain.
- 11.6: Peripheral Nervous System
- Did you ever see two people play the same piano? How do they coordinate all the movements of their own fingers, let alone synchronize them with those of their partner? The peripheral nervous system plays an important part in this challenge.
- 11.7: Human Senses
- This figure appears at first glance to be just a pattern of colored leaves, but hidden within it is the three-dimensional shape of an ant.
- 11.8: Psychoactive Drugs
- Who knew that a cup of coffee could also be a work of art? A talented barista can make coffee look as good as it tastes. If you are a coffee drinker, you probably know that coffee can also affect your mental state.
- 11.9: Case Study Memory Conclusion and Chapter Summary
- The nervous system coordinates all of the body's voluntary and involuntary activities. It interprets information from the outside world through sensory systems and makes appropriate responses through the motor system, through communication between the PNS and CNS. The brain directs the rest of the nervous system and controls everything from basic vital functions such as heart rate and breathing to high-level functions such as problem-solving and abstract thought.
Thumbnail: Cerebral lobes. Image used with permission (CC BY SA 3.0 Unported; Gutenberg Encyclopedia).