biopsych

• Nervous system


  Provides the biological basis of psychological experience
• Divisions of the nervous system

  • Central nervous system -brain and spinal cord
  • Peripheral nervous system
  • somatic nervous system
  • autonomic nervous system
  • parasympathetic nervous system
  • sympathetic
• Components of the peripheral nervous system

  • Somatic nervous system
  • Autonomic nervous system
• Components of the autonomic nervous system

  • Sympathetic nervous system
  • Parasympathetic nervous system
• Central nervous system


  • Brain and spinal cord
  • Maintains life
  • Involved in higher functions and psychological processes
• Spinal cord


  • Transfers messages to and from the brain
  • Responsible for simple reflex actions
• Somatic nervous system


  • Facilitates communication between the CNS and the outside world
  • Carries sensory information from the outside world to the brain
  • Provides muscle responses via motor pathways
• Autonomic nervous system


  • Plays an important role in homeostasis
  • Only consists of motor pathways
  • Internal organs
• Sympathetic nervous system


  • Involved in responses that prepare the body for fight or flight
  • Increases heart rate, blood pressure, breathing rate
  • Suppresses less important functions like digestion
• Parasympathetic nervous system


  • Relaxes the body and returns it to a resting state
  • Slows down heart rate, breathing rate, and reduces blood pressure
  • Starts up functions that were previously slowed down
  • rest and digest
• Sensory neurons


  Found in receptors, carry nerve impulses to the spinal cord and brain, translate into sensations

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• Relay neurons


  Found between sensory input and motor output/response, allow sensory and motor neurons to communicate

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• Motor neurons


  Found in the CNS, control muscle movements, release neurotransmitters that bind to muscle receptors to trigger a response

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• Synaptic transmission


  1. Electrical impulse (action potential) reaches axon terminal

  2. Synaptic vesicles release neurotransmitters across synaptic gap

  3. Neurotransmitters bind to receptors on post-synaptic cell

  4. Excitatory or inhibitory effects on post-synaptic cell
• Excitatory neurotransmitters


  Make the post-synaptic cell more likely to fire (e.g. noradrenaline)
• Inhibitory neurotransmitters


  Make the post-synaptic cell less likely to fire (e.g. GABA)
• Glands of the endocrine system

  • Hypothalamus
  • Pituitary gland
  • Pineal gland
  • Thymus
  • Thyroid and parathyroid glands
  • Pancreas
  • Ovary
  • Adrenal glands
  • Testicles
  • Placenta
• Hypothalamus


  Control system that regulates the endocrine system, connected to the pituitary gland
• Pituitary gland


  Master gland, releases hormones that control and stimulate other endocrine glands
• Melatonin


  Hormone released by the pineal gland, responsible for biological rhythms including sleep-wake cycle
• Thyroxine


  Hormone released by the thyroid gland, regulates metabolism
• Adrenaline and noradrenaline


  Hormones released by the adrenal medulla, play a key role in the fight or flight response
• Cortisol


  Hormone released by the adrenal cortex, stimulates release of glucose and suppresses the immune system
• Testosterone


  Hormone released by the testes, responsible for development of male sex characteristics and muscle growth
• Oestrogen


  Hormone released by the ovaries, controls regulation of the female reproductive system
• Fight or flight response

  1. Amygdala activated by sensory input

  2. Amygdala sends distress signal to hypothalamus

  3. Hypothalamus activates sympathomedullary pathway

  4. Sympathetic nervous system stimulates adrenal medulla

  5. Adrenal medulla secretes adrenaline and noradrenaline

  6. Physiological changes to prepare body for fight or flight
• Physiological changes in fight or flight

  • Increased heart rate
  • Increased breathing rate
  • Pupil dilation
  • Sweat production
  • Reduction of non-essential functions (e.g. digestion)
• After fight or flight response

  Parasympathetic nervous system activated to return body to resting state
• Humans may engage in an initial 'freeze' response before fight or flight
• Functions of the eye

  • Ease light entry into the eye
  • Enhance vision (especially in the dark)
• Functions of the eye

  • To regulate temperature
  • To increase energy for other essential functions
• Fight or flight response

  1. Activation of parasympathetic nervous system

  2. Slows down heart rate and breathing rate

  3. Reduces blood pressure

  4. Starts up functions that were previously slowed down (e.g. digestion)
• Reactions to danger


  • Initial 'freeze' response
  • Hyper-vigilance while appraising the situation
  • Deciding best course of action
• Fight or flight response


  Typically a male response to danger
• Tend and befriend response


  • More likely female response in stressful/dangerous situations
  • Protect offspring
  • Form alliances with other women
• The fight or flight response may be counterintuitive for women, as running (flight) might be seen as a sign of weakness and put their offspring at risk of danger
• Early research into the fight or flight response was typically conducted on males (androcentrism) and consequently, researchers assumed that the findings could be generalised to females
• This highlights a beta bias within this area of psychology as psychologists assumed that females responded in the same way as males, until Taylor provided evidence of a tend and befriend response
• While the fight or flight response may have been a useful survival mechanism for our ancestors

  Modern day life rarely requires such an intense biological response
• The stressors of modern day life can repeatedly activate the fight or flight response


  Can have a negative consequence on our health (e.g. damage to blood vessels and heart disease)