Psychology help

[lenny]

Will someone please help me with what the HPA and SAM are (and maybe some evaluative points). Preferably no googled answers, I'd rather psych students gave it a go. +rep for best answer

[Sci_Girl]

What exactly do you need to know? Both are simply anatomy based systems so the answers are going to be roughly the same in any textbook and online. I can help you out though depending on what you need.

[trix]

Oooh we just did a quick essay question on this the other week so I can give you my 8-mark answer. First paragraph's about the SAM and second is about the HPA...I got full marks btw ;)

When the body is exposed to an acute stressor the sympathetic nervous system (SNS) and the sympathetic adrenal medullary (SAM) will be triggered simultaneously. The SAM stimulates the endocrine system to release the hormone adrenaline from the adrenal glands in the adrenal medulla, into the blood stream. In turn this hormone prepares the body for its 'fight or flight' response by boosting the supply of oxygen and glucose to the brain and muscles through increased heart and breathing rates and by stopping non-emergency process like digestion (peristalsis) and salivation. The SAM also triggers the release of a small amount of noradrenaline from the adrenal medulla. Noradrenaline is a neurotransmitter (not a hormone) that maintains sympathetic activation (activation of the sympathetic nervous system) and thereby stimulates the release of more adrenaline. This is called positive feedback.

The hypothalamic-pituitary-adrenal axis (HPA) is the system that is activated by a long-term or chronic stressor (i.e. stressors continuous over an extended period of time such as prolonged unemployment or the death of a close friend). These chronic stressors alert the hypothalamus within the brain to stimulate the release of corticotropin-releasing hormone (CRH) into the bloodstream. The CRH in turn stimulates the pituitary gland to release adrenocorticotropic hormone (ACTH) which travels in the blood stream to the adrenal glands just above the kidneys, triggering the release of stress-related hormones including cortisol. Cortisol increases blood sugar levels, giving an individual a constant source of energy in order for them to be able to deal with the stressor. Cortisol also raises the individual's pain threshold however it leads to reduced immune system performance and impaired cognitive ability.

:D I got 8/8 marks. PM me if you need more help.