Chapter 2 - Homeostatis And Allostasis Flashcards
Selye’s theory of a GAS
There is a nonspecific physiologic response to stress.
Alarm, Resistance, Exhaustion
What does the perception of stressors depend on?
Genetics, gender, past experiences and conditioning, and cultural influence.
Define Risk Factor
Conditions or situations that increases the likelihood of encountering or experiencing a stressor
What are endorphins and enkephalins?
What do they do?
They are endogenous opioids produced by the CNS.
They function to raise the pain threshold; REDUCE PAIN. They also produced sedation and euphoria.
They activate immune cells to release pro-inflammatory cytokines to act as mechanism to alert you of pain. (If you don’t feel it, you won’t fix it).
What do cytokines do?
Involved with body’s immune signaling systems to regulate between stress and immunity. The cytokines are a signaling system.
Where is norepinephrine released from and what effect does it have on the body?
Norepinephrine is released from the sympathetic nerve endings.
Norepinephrine increases heart rate, respiratory rate, blood pressure and constricts blood vessels to decrease blood flow to non-necessary tissues, decreases gastrointestinal motility and decreases blood gastric acid secretion, dilates pupils, and inhibits insulin secretion
What is epinephrine’s role in the stress response and where is epinephrine released from?
Epinephrine is released from the adrenal medulla.
Epinephrine works to increase cardiac rate, cardiac contractility, and cardiac output. Epinephrine promotes glucose release from the liver and enhances bronchodilation
Where does Cortisol come from? What is cortisol’s role?
Cortisol is released from the adrenal cortex. It is both synergistic and antagonistic with catecholamines, and has an anti inflammatory role.
What is aldosterone’s role in the stress response?
Aldosterone’s promotes fluid volume expansion and increases blood pressure.
Define Allostasis
A process of attaining and maintaining stability through change, and leads to a state of adaptation.
A network of biopsychosocial processes of responding to a stressor with the goal of reestablishing homeostasis.
What is Allostatic load?
The wear-and-tear effect of adaptation on the body and mind.
When does allostatic load occur?
Allostatic load occurs as mediators produced by the stress response accumulate and contribute to tissue damage overtime. It’s the cumulative costs of adaptation.
What is allostatic overload?
A number of disorders that are related to excessive stress or an inappropriate stress response as a result of dysregulation and excessive use of the mechanisms and mediators from the stress response.
What is Allostasis
The overall process of ADAPTIVE change necessary to maintain survival and well-being.
Allostasis may involve altering multiple physiologic variables in order to match the resources of the body to environmental demands = Allostasis helps the body achieve homeostasis.
