Nervous System Organization and Functions

Organization of the Nervous System

• Central Nervous System (CNS): brain and spinal cord
• Peripheral Nervous System (PNS): nerves that connect CNS to rest of body
  • Somatic Nervous System: controls voluntary movements and sensations
  • Autonomic Nervous System (ANS): controls involuntary functions (heart rate, digestion, etc.)

Functions of the Nervous System

• Integration: processes and interprets sensory information
• Control: regulates body functions and movements
• Coordination: integrates sensory information with motor responses

Neurons and Synapses

• Neurons: specialized cells that transmit information
  • Dendrites: receive signals
  • Cell Body: integrates signals
  • Axon: transmits signals
• Synapses: gaps between neurons where chemical transmission occurs
  • Neurotransmitters: chemical messengers released by neurons
  • Receptors: bind to neurotransmitters to transmit signals

Types of Neurotransmitters

• Excitatory: increase likelihood of action potential (e.g. glutamate, aspartate)
• Inhibitory: decrease likelihood of action potential (e.g. GABA, glycine)
• Modulatory: influence strength and duration of synaptic transmission (e.g. dopamine, serotonin)

Action Potential

• Resting Potential: -70mV, due to higher K+ concentration inside neuron
• Threshold Potential: -55mV, where action potential can occur
• Action Potential: rapid depolarization to +30mV, followed by repolarization
• Refractory Period: period after action potential where neuron cannot fire again

Neurophysiological Processes

• Sensory Transduction: conversion of sensory stimuli into electrical signals
• Pain Perception: transmission of painful stimuli through nociceptors
• Motor Control: transmission of motor signals from CNS to muscles
• Learning and Memory: formation and consolidation of new connections between neurons

Organization of the Nervous System

• The Central Nervous System (CNS) consists of the brain and spinal cord.
• The Peripheral Nervous System (PNS) comprises nerves that connect the CNS to the rest of the body.
• The PNS is divided into the Somatic Nervous System, which controls voluntary movements and sensations, and the Autonomic Nervous System (ANS), which controls involuntary functions such as heart rate and digestion.

Functions of the Nervous System

• The Nervous System processes and interprets sensory information through integration.
• It regulates body functions and movements through control.
• It integrates sensory information with motor responses through coordination.

Neurons and Synapses

• Neurons are specialized cells that transmit information, consisting of dendrites, cell body, and axon.
• Dendrites receive signals, the cell body integrates signals, and the axon transmits signals.
• Synapses are gaps between neurons where chemical transmission occurs, using neurotransmitters to transmit signals.
• Neurotransmitters are chemical messengers released by neurons, binding to receptors to transmit signals.

Types of Neurotransmitters

• Excitatory neurotransmitters, such as glutamate and aspartate, increase the likelihood of an action potential.
• Inhibitory neurotransmitters, such as GABA and glycine, decrease the likelihood of an action potential.
• Modulatory neurotransmitters, such as dopamine and serotonin, influence the strength and duration of synaptic transmission.

Action Potential

• The resting potential of a neuron is -70mV due to a higher K+ concentration inside the neuron.
• The threshold potential is -55mV, where an action potential can occur.
• An action potential involves rapid depolarization to +30mV, followed by repolarization.
• The refractory period is the time after an action potential when the neuron cannot fire again.

Neurophysiological Processes

• Sensory transduction involves converting sensory stimuli into electrical signals.
• Pain perception involves the transmission of painful stimuli through nociceptors.
• Motor control involves transmitting motor signals from the CNS to muscles.
• Learning and memory involve the formation and consolidation of new connections between neurons.

Learn about the central and peripheral nervous systems, as well as the functions of the nervous system, including integration and control.