Stress and NS

• Synaptic plasticity

  The brains ability to reorganise its neural pathways when damaged or when adapting to new experiences
• Adaptive plasticity

  Response to experience or recover from damage
• Developmental plasticity

  Occurring according to genetic blueprint
• Long-term potentiation

  Long-lasting strengthening through repeated stimulation of pre and post synaptic neuron
• Sprouting

  Growth of new branches on axons or dendrites to enable new connections
• Central nervous system is composed of brain and spinal cord
• Spinal cord acts as a pathway for messages to get to the brain
• Central nervous system consists of the brain and spinal cord
• Spinal cord acts as a pathway for messages to get to the brain and body
• Brain is the engine room - receives, processes and coordinates a response for rest of the body
• Peripheral nervous system consists of all the nerves outside the CNS
• PNS consists of somatic and autonomic nervous systems
• Somatic nervous system is responsible for all voluntary responses (e.g take off jumper, kick a ball)
• Autonomic nervous system is responsible for involuntary responses (e.g sweating, heart rate)
• ANS consists of parasympathetic nervous system, sympathetic nervous system and enteric nervous system
• Sympathetic nervous system is activated when the body is under stress or threat (e.g increase sweating, heart rate, breathing, pupils dilate)
• Enteric nervous system responsible for the process of digestion
• Parasympathetic nervous system bring body back to peace/calm, back to homeostasis (e.g lowers sweat, heart rate, breathing rate, pupils constrict)
• Conscious response to a sensory stimulus is a reaction that involves awareness
• An unconscious response to a sensory stimulus is a reaction that doesn't involve awareness
• Spinal reflex - unconscious response
• Spinal reflex

  • A sensory neuron detects the message and relays the message to the spinal cord
  • An interneuron then passes this message to a motor neruon
  • A motor response then follows
• Ascending tracts (afferent)

  Allow for sensory info to travel from body to brain via spinal cord
• Descending tracts (efferent)

  Allow for motor messages to travel from the brain to relevant parts of the body via the spinal cord
• Sprouting and rerouting are a key process of LTP
• LTP helps in learning and memory formation
• Synaptic pruning - result of LTD
• Stress is the physiological and psychological responses that a person experiences when confronted with a situation that is threatening or challenging
• Stress

  Experienced when a person perceives that the demands of threeatening or challenging situation exceeds their ability to cope
• Stress can be internal or external
• Distress

  Negative responses to stressor by presence of negative psychological states such as anxiety, anger, fear, feeling helpless or hopeless
• Eustress

  Positive responses to stressor by positive psychological states such as excitement, enthusiastic and optimism
• Acute stress

  Can be intense, but usually appears and disappears over a short-period of time so it doesnt cause psychological or physical damage
• Chronic stress

  Long-lasting, pressures and worries that we do not feel we have under control and will not end
• Cortisol - primary stress hormone
• Cortisol

  Secreted directly into the bloodstream for transportation throughout the body
• Cortisol

  Short term - energy burst, adrenaline

  Long term - suppresses the immune system
• Fight - confront threat, activation of sympathetic ns energises body and prepares for fight
• Flight - flee from danger, activation of sympathetic ns allows body to flee quickly
• Freeze - immobility, brief activation of the parasympathetic NS as some bodily reactions drop below normal levels (e.g. blood pressue). The sympathetic NS is also activated so the body is ready to spring into action