Unit 2: Biological Psychology (Stress)

There are three basic assumptions of the biological approach:
1. Human behaviour is controlled by biological factors such as hormones, genetics, evolution and the nervous system
2. We can explain all behaviour using biological causes, unwanted behaviour could be modified or removed using biological treatments such as medication
3.  Experimental research conducted on animals can inform us about human behaviour and biological influences because we share a lot of biological similarities

Brain scanning is used to investigate possible abnormalities:
- Magnetic Resonance Imaging (MRI) scans use magnetic fields to produce a detailed image of the brain that can show up abnormalities such as tumours and structural problems. It can also show brain activity and blood flow to different areas.
- Positron Emission Tomography (PET) scans can measure brain activity by using sensor placed on the head to track a radioactive substance that is injected into the person. PET scans can show which areas of the brain are more active when the person performs an activity such as counting. This helps us to understand about function of communication within the brain.

Biological Approach Strengths:
- Can provide evidence to support or disprove a theory - it's a very scientific approach
- If a biological cause can be found for mental health problems or for unwanted behaviour such as aggression, then biological treatments can be developed to help individuals 

Weaknesses:
- The approach doesn't take into account the influence of people's environment, their family, childhood experiences or their social situation. Other approaches see these as being important factors in explaining behaviour
- Using a biological explanation for negative behaviour can lead to individuals or groups avoiding taking personal or social responsibility for their behaviour

What is stress?
- Environmental stimulus that triggers a stress response
- Response to the stimulus
- "The response that occurs when we think we cannot cope with the pressures in our environment"

Physiological Stress Response:
- Increase in heart rate
- Alterations in digestive activity
- Skin becomes pale
- Sweating increases
- Muscular tremors

Sympathomedullary Pathway
Hypothalamus triggers the activity activity in the sympathetic brand of the ANS. This sends a signal to the adrenal medulla which releases adrenaline and noradrenaline into the bloodstream. 

Sympathomedullary pathway uses electrical impulses through the nerve fibres, making it very quick

Pituitary-adrenal System
A stressor is sensed and the hypothalamus readies the body for action. The hypothalamus signals the pituitary gland to release adrenocorticotropic hormone (ACTH). Adrenal Cortex detects the ACTH and releases more hormones called corticosteroids which aid with the clotting of blood and give us energy by converting fat and protein. 

Known as the hypothalamic pituitary adrenal (HPA) system, chemical/hormone based so it is fast but not as fast as the sympathomedullary pathway.

"Fight or Flight" Response
An early evolutionary adaption that is useful in dealing with physical threats. Helps us deal with short term problems by either fighting or running away. Unfortunately, may of the problems we face in modern day society cannot be solved in this…