The Nervous System Overview

Nervous System

Overview

• The nervous system is a complex system that allows the body to respond to internal and external stimuli
• It consists of two main parts: the Central Nervous System (CNS) and the Peripheral Nervous System (PNS)

Central Nervous System (CNS)

• Consists of the brain and spinal cord
• Responsible for:
  • Integrating and processing information
  • Controlling voluntary movements
  • Regulating body functions (e.g. heart rate, blood pressure)
• Protected by the blood-brain barrier, a selective barrier that allows certain substances to pass through

Peripheral Nervous System (PNS)

• Consists of nerves that connect the CNS to the rest of the body
• Divided into two subsystems:
  • Somatic Nervous System: controls voluntary movements (e.g. movement of muscles)
  • Autonomic Nervous System: controls involuntary movements (e.g. heart rate, digestion)

Neurons

• Basic units of the nervous system
• Consist of:
  • Dendrites: receive signals from other neurons
  • Cell body: contains the nucleus and maintains the cell
  • Axon: carries signals away from the cell body
  • Terminal buttons: release neurotransmitters to transmit signals

Synapses

• Gaps between neurons where chemical signals are transmitted
• Neurotransmitters released from terminal buttons bind to receptors on adjacent neurons
• Strength of synaptic connections can be modified through experience (synaptic plasticity)

Nervous System Functions

• Sensation: detection of internal and external stimuli
• Perception: interpretation of sensory information
• Movement: voluntary and involuntary movements
• Regulation: control of body functions (e.g. heart rate, blood pressure)
• Control: coordination of movements and responses

Nervous System Overview

• Complex system allowing body to respond to internal and external stimuli
• Consists of two main parts: Central Nervous System (CNS) and Peripheral Nervous System (PNS)

Central Nervous System (CNS)

• Comprises brain and spinal cord
• Responsible for integrating and processing information, controlling voluntary movements, and regulating body functions like heart rate and blood pressure
• Protected by blood-brain barrier, a selective barrier allowing certain substances to pass through

Peripheral Nervous System (PNS)

• Consists of nerves connecting CNS to rest of body
• Divided into Somatic Nervous System, controlling voluntary movements like muscle movement, and Autonomic Nervous System, controlling involuntary movements like heart rate and digestion

Neuron Structure and Function

• Basic units of nervous system consisting of dendrites, cell body, axon, and terminal buttons
• Dendrites receive signals from other neurons
• Cell body contains nucleus and maintains cell
• Axon carries signals away from cell body
• Terminal buttons release neurotransmitters to transmit signals

Synaptic Transmission

• Chemical signals transmitted across gaps between neurons (synapses)
• Neurotransmitters released from terminal buttons bind to receptors on adjacent neurons
• Strength of synaptic connections can be modified through experience (synaptic plasticity)

Nervous System Functions

• Sensation: detection of internal and external stimuli
• Perception: interpretation of sensory information
• Movement: voluntary and involuntary movements
• Regulation: control of body functions like heart rate and blood pressure
• Control: coordination of movements and responses