Stress: Where the perceived demands of a situation are greater than a person's ability to cope.
Body's response to stress occurs in two ways:
1) Acute stress (Short-term) E.g. exams
2) Chronic stress (Long-term) E.g. death of someone
There are two main ways in which our body responds to stress, and both involves the adrenal gland.
Adrenal glands are found lying just above the kidneys.
The adrenal gland is made up of 2 distinct sections
1) Sympathetic-adrenomedullary (SAM) pathway - for ACUTE stress
2) Hypothalamic-pituitary-adrenal (HPA) axis - for CHRONIC stress
The SAM pathway is known as the sympathetic adrenomedullary system.
The sympathetic nervous system (SNS) is activated in response to acute stress.
Firstly the hypothamalus triggers activity in the sympathetic branch of the autonomic nervous system.
The nerve pathways of the SNS originate in the brain stem and travels through the spinal nevres to other body organs.
One of these pathways stimulates the adrenal medullar wich can be found above the kidney.
This then releases the hormones adrenaline and noradrenaline into the bloodstream.
This then gets the body ready for flight or fight.
When the body does react it accelerates the heartbeat, increases breathing and the person may start to sweat
The HPA system
The hypothamalus stimulates the pituitary gland whih releases the stress hormone called ACTH.
The hormone travels to the adrenal cortex, part of teh adrenal gland and this secrees the release of cortisol into the bloodstream.
After this the body's reaction may be
- lowers the immune system
- lowers sensitivity pain
- Causes liver to release energy