Biological approach

• KEY ASSUMPTIONS

  • genes influence a persons behaviour
  • belief that behaviour evolves like physical characteristics
  • the CNS is the main focus of behaviour
  • neurotransmitters and hormones influence behaviour
  • evolution
• genotype

  your genetic makeup
• phenotype

  observable characteristics due to expressed genes and environment
• how many pairs of chromosomes in 1 somatic cell

  23
• monozygotic

  twins from one zygote (identical)
• dizygotic

  twins from two zygotes (non-identical)
• monozygotic twins share all genotypes but not all phenotypes
• NERVOUS SYSTEM

  A Central nervous system

  B Peripheral nervous system

  C Autonomic nervous system

  D Somatic nervous system

  E Parasympathetic division (rest and digest)

  F Sympathetic division (fight or flight)

  
• the fight or flight response

  hypothalamus secretes hormone -> stimulates adrenal medulla -> secretes adrenaline and noradrenaline
• SAM

  • Sympathetic adrenal medullary pathway
  • short term stress
  • increased blood pressure for more blood to muscles
  • dilated pupils to let in more light
  • breathing rate increases for more oxygen into body
  • salivation decreases as digestion not a priority
• HPAC

  • Hypothalamic pituitary adrenocortical axis
  • long term stress
  • counter shock response
  • hypothalamus releases hormones -> stimulates anterior pituitary gland -> releases ACTH -> stimulates adrenal cortex -> releases cortisol -> impacts glucose metabolism
• ACTH

  Adrenocorticotrophic hormone
• sensory neuron


  A receptor cell

  B myelin sheath

  C axon

  D cell body / soma

  
• relay neuron


  A dendrite

  B cell body / soma

  C axon

  D axon terminals

  
• motor neuron


  A dendrite

  B cell body / soma

  C myelin sheath

  D axon

  E node of ranvier

  
• SYNAPTIC TRANSMISSION

  1 nerve impulse travels down presynaptic neuron

  2 stimulates vesicles to move towards terminals

  3 vesicles fuse with presynaptic membrane and NTs diffuse into synaptic fluid

  4 NTs diffuse across synapse to receptor site and bind with postsynaptic neuron

  5 nerve impulse is initiated in postsynaptic neuron

  6 NTs diffuse back into synapse and break down or are reuptaken by presynaptic neuron
• excitatory

  more likely to fire
• inhibitory

  less likely to fire
• summation

  excitatory and inhibitory effects summed to the net effect of how likely an impulse is to fire
• STRENGTHS

  • uses scientific method
  • objective approach
  • practical applications
• WEAKNESSES

  • deterministic
  • reductionist
  • no focus on nurture