nervous system

• Neurons are specialized cells that transmit information throughout the nervous system.
• The central nervous system comprises of the brain and the spinal cord
• The peripheral nervous system is every neuron apart from the brain and the spinal cord
• The somatic nervous system transmits neural messages about voluntary motor movement
• The autonomic nervous system regulates visceral muscles and glands, controls unconscious responses.
• Sympathetic nervous system activates visceral, muscles, organs and glands, preparing the body to respond to a threat or stressor. Energises the body to engage in high levels of physical activity and confront threatening or stressful situation.
• Sympathetic nervous system

  simp (try hard) prepare body to confront stressor
• Parasympathetic nervous system relaxes visceral muscles, slows down heart rate, constricts pupils, stimulates digestion, reduces blood pressure, conserves energy, restores homeostasis when sympathetic nervous system has been activated.
• neurons are nerve cells that recieve and transmit neural info
• interneurons transfer neural messages between motor and sensory neurons
• Conscious responses are deliberate and voluntary actions initiated by the brain peformed intentionally by the body
• Unconscious responses are automatic involuntary response performed by the body independently from the brain
• Spinal reflex unconscious response to sensory stimuli initiated by interneurons in spinal cord independently of the brain
• presynaptic neuron releases neurochemicals into neural synapse from its axon terminal
• postsynaptic neurons accept neurochemicals because of receptor sites located on dendrites
• neurotransmitters are chemical molecules that effect 1 or 2 postsynaptic neurons
• Glutamate


  excitatory effect

  learning and memory

  strengthen synaptic connections (long-term potentiation) because of repetitive coactivation
• gamma amino-butyric acid (GABA)

  inhibitory effect

  stops overexcitation

  reduces anxiety

  inhibits uncontrolled firing of action potentials

  prevents seizures
• neuromodulators are chemical molecules that have an effect on multiple postsynaptic neurons

  
  

  released into multiple neural synapses effecting multiple postsynaptic neurons

  
  

  widespread modulatory effects, influence large area of brain tissue

  
  

  long-lasting effects as they modulate neural activity more slowly than neurotransmitters
• DOPAMINE

  primarily responsible for voluntary motor movement

  pleasure and reward based learning
• serotonin is involved with mood regulation, sleep, appetite, and sexual behaviour, depression
• synaptic plasticity


  ability of synaptic connections to change over time in response to activity or experience
• SPROUTING

  dendrites or axons develop NEW extensions or branches
• PRUNING

  "use it or lose it"

  elimination of synaptic connections that are not adequately activated necessary to accommodate stronger and more essential synaptic connections
• LEARNING

  process off acquiring knowledge skills, behaviours, through experience
• MEMORY

  process of encoding, storing, retrieving info that has been previously encountered
• LONG-TERM POTENTIATION


  long-lasting experience dependent strengthening of synaptic connections that are regularly coactivated like in learning and memory
• STRUCTURAL CHANGES TO NEURAL SYNAPSE IN LONG-TERM POTENTIATION:

  • increased number of receptor sites on dendrites of postsynaptic neuron
  • bushier/thicker dendrites on postsynaptic neuron (sprouting)
  • increased number of synaptic connections between neurons (sprouting)
• STRUCTURAL CHANGES TO NEURAL SYNAPSE LONG-TERM DEPRESSION:

  • decreased number of receptor sites on dendrites of postsynaptic neuron
  • decreased number of dendrites on postsynaptic neuron (pruning)
  • decreased number of synaptic connections between neurons (pruning)
• LONG-TERM DEPRESSION


  long-lasting experience dependent weakening of synaptic connections between neurons that are not regularly coactivated.