Stress - The Stress Response SAM and HPA Flashcards
Define stress
when a person’s perceived environmental, social and physical demands exceeds their perceived ability to cope, especially when the demands are seen as endangering well being in some way.
What are the two major systems in the ‘stress response’?
Sympathomedullary Pathway (SAM) and the Hypothalamic Pituitary Adrenal system or axis (HPA)
What is the ANS and what does it consist of?
Autonomic Nervous System which is the nervous system which operate automatically - it consists of the Sympathetic and Parasympathetic Nervous systems
What is the role of the Sympathetic Nervous System?
To prepare us - to quickly push the body into action in the face of a stressor - to arouse us ready for fight or flight - to use energy quickly.
What is the role of the Parasympathetic Nervous System?
To relax us - to calm us down - to conserve energy - to bring us back to ur normal state. Sometimes referred to as the ‘rest and digest’ system.
What is a stressor?
Anything that causes stress
What are the two main types of stress?
Acute (short term) and Chronic (longer term)
What is a neurotransmitter?
A substance that is released from the end of a neutron (brain cell) into the gap between neurones to excite or inhabited another neuron.
What are the some of the physical responses to the Sympathetic Nervous system?
Noradrenaline released (neurotransmitter), Increase in pupil size to let in more light, increase in Heart rate for increased blood flow to skeletal muscles, glycogen stores in liver converted to glucose for energy, bronchial tubes dilate for increase oxygen intake, sweat gland stimulated to sweat more and reduce heat, adrenal medulla stimulated to release adrenaline. Digestion is suppressed.
Describe the SAM pathway (Sympathomedullary Pathway)
The SAM system releases noradrenaline which travels to the adrenal medulla which then releases adrenaline (epinephrene) into the bloodstream where it is transported rapidly around the body to prepare for fight or flight. The adrenal medulla
Where is the hypothalamus?
In the limbic system of the brain
What is the role of the Hypothalamus in the HPA system?
When stressors are perceived the hypothalamus receives the message and acts as the control centre for the production of hormones
What does PVN stand for?
Paraventricular Nucleus - a region of the hypothalamus linked to the production of corticotrophin releasing factor (CRF)
What is CRF?
Corticotrophin Releasing Factor - a chemical messenger responsible for the release of Adrenocorticotrophic Hormone (ACTH) from the pituitary gland
Where is the pituitary gland?
In the limbic system of the brain near the hypothalamus
