The Physiology of stress

Pituitary and Adrenal glands 
Pituitary gland  Releases hormones into the bloodstream. It is about the size of a pea at the base of the brain. 
Adrenal Glands  These sit at the top of the kidneys and are responsible for releasing stress hormones. 

GAS

- Selye argued that stressors produce the same reaction in all animals (including humans). He called this the General Adaptations Syndrome (GAS), and identified three main stages. 
-Alarm Strong emotional response = fear/anxiety involves; dilated pupils, increased heart rate, tightened muscles, Hypothalamus activated, sweating and slowed digestion.
- Resistance if a stressor persists, the release of hormones from the pituitary gland and the adrenal cortex increases and the alarm symptoms of the first stage subside, giving the appearance of a return to normal physicological functioning
- Exhaustion If the stressor persists for longer than the body's defences can cope with, then the adrenal glands cease to function normally and there is a drastic fall in blood sugar levels. 

The Autonomic Nervous system (ANS)
The role of the ANS is to control the release of hormones controlled by higher brain structures such as the hypothalamus. 
The ANS transmits hormones to all body organs via nerve pathways e.g. heart, digestive system, circulatory system. 
- Sympathetic = Prepares the body for stressful situations. Produces a pattern of bodily arousal. Heart rate and blood pressure levels rise, digestive system slows down. 
- Parasympathetic = Controls body in ordinary situations. Opposite to above in that heart rate and blood pressure return to normal, digestion speeds up. 

The body's response to stress. 

Two main ways our body responds to stres.
- The hypothalamus plays a central role.
- The Adrenal cortex and adrenal medulla are the two adrenal glands that release different hormones in response to stress. 

Stress pathways 
There are 2 pathways that show our bodily reaction to stress 
1. Sympathetic-adrenal Medulla pathway (SAM)

2. Hypothalamic-Pituitary-Adrenal cortex pathway (HPA)

ACUTE STRESS Sympathetic -Adrenal Medulla Pathway (SAM) 

- The Sympatheic branch of the ANS  (Autonomic nervous system) is activated by the hypothalamus.
- The Adrenal…