Overview of the Nervous System Chapter Notes | AP Psychology - Grade 11 PDF Download

Introduction

Imagine your body as a super-smart computer, and the nervous system is its main control panel, buzzing with activity to keep everything running smoothly. This incredible network is responsible for everything from helping you dodge a flying ball to making your heart beat without you even thinking about it. In this chapter, we’ll explore how the nervous system is organized into two major parts—the central and peripheral nervous systems—and how they work together to manage your thoughts, movements, and automatic functions. From the brain’s big decisions to the nerves that carry messages to your toes, get ready to uncover the wiring that powers you!

Overview of the Nervous System

• Nervous system acts as body’s control center.
• Divided into two main parts:
  1. Central nervous system includes brain and spinal cord, managing all body activities.
  2. Peripheral nervous system includes nerves outside brain and spinal cord, linking body to central nervous system.
• Peripheral nervous system splits into autonomic and somatic nervous systems.
• Autonomic nervous system controls automatic functions like breathing and heartbeat.
• Somatic nervous system handles voluntary movements and senses.

Key Components and Their Roles

Nervous system has different parts with specific roles.

• Central nervous system (CNS): brain and spinal cord, controls all body functions.
• Peripheral nervous system (PNS): connects CNS to rest of body.
• Autonomic nervous system (ANS): manages automatic processes.
  • Sympathetic division: speeds up body for fight-or-flight response.
  • Parasympathetic division: slows down body for rest-and-digest mode.
• Somatic nervous system (SNS): controls voluntary movements and sensory information.

Subsystems of Nervous System

Central Nervous System Functions

• Serves as main control center for all neural activities.
• Brain and spinal cord coordinate body functions.
• Processes sensory information from body.
• Generates motor commands for movement and behavior.
• Integrates neural signals for coordinated responses.
• Supports higher cognitive functions, including:
  • Memory formation and recall.
  • Learning and adaptation.
  • Conscious thought and emotion.
  • Perception and awareness.

Peripheral Nervous System Functions

• Acts as communication network between central nervous system and body.
• Consists of nerves and ganglia outside brain and spinal cord.
• Collects sensory information from body receptors.
• Relays signals to and from central nervous system.
• Carries motor commands to muscles and glands.

 This system divides into two major components:

1. Autonomic Nervous System

• Regulates involuntary processes.
• Parasympathetic division controls rest-and-digest functions.
• Sympathetic division manages fight-or-flight responses.

2. Somatic Nervous System

• Controls voluntary muscle movements.
• Enables conscious physical interactions with environment.
• Processes sensory information like touch and pressure.

Autonomic vs Somatic Nervous Systems

• Autonomic and somatic systems have different but complementary roles.
• Autonomic system works automatically without conscious control.
• Autonomic system maintains vital processes, such as:
  • Breathing rhythm.
  • Heart rate regulation.
  • Digestive functions.
• Autonomic system balances sympathetic (arousal) and parasympathetic (calming) responses.
• Somatic system allows voluntary control over environmental interactions.
• Somatic system enables intentional muscle movements and coordinated motor skills.
• Both systems work together through:
  • Integrated nerve networks.
  • Complementary sensory and motor pathways.
  • Coordinated responses to internal and external demands.