Biopsychology: models and processes


Synaptic Transmission

1. A message travels along the axon as an electrical impulse

2. As it reaches the pre-synaptic neuron it changes to a chemical impulse

3. This then triggers the vesicles in the axon terminals to release neurotransmitters that will help the chemical impulse to pass across the synpatic cleft.

4. As the neurotransmitter meets a specific receptor, it allows for the chemical message to pass inot the post-synaptic neuron. 

5.Once the receptors have been activated, they either produce excitatory or inhibitory effects on the post-synaptic cell.

6. In the post-synaptic neuron, is where the chemical impulse will now return back into an electrical impulse.

7. Following this, an ion channel will open in the membrane and allow for the electrial impulse to pass through the dendrites

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HPA and SAM pathways


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Fight or Flight response

1.Begins with an assessment of the situation followed by the activation of the two key pathways.

2.The appraisal depends on the sensory processinghg systems (e.g sight and hearing) as well as stored memories of previous encounters with the same sitaution

3.If the situation is appraised as 'dangerous' the hypothalamus is alerted to release hormones via the pituitary gland

4.The HPA releases the adrenocorticotrophic hormone (ACTH) into the bloodstream. From here it travels to the adrenal cortex and stimulates the release of glutocorticoids into the bloodstream. 

5.At the same time SAM pathway is activated by the release of ACTH, which triggers the Sympathetic Nervous System (SNS) and the pathways runnin to the adrenal medulla. This triggers an increased release of adrenaline and noradrenaline into the bloodstream.

6. Circulating adrenaline and corticosteriods increases the release and mobilization of our energy reserves and thus we are prepared to fight or flight. 

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