Stress as a biological process Learning Questions What

Stress as a biological process Learning Questions: What are the physiological responses to stress? What is the fightflight-freeze response? To start - one minute challenge! Revise you notes on sources of What role does stress for 2 minutes. You must cortisol play in then be prepared to talk about the response to stress? topic for 1 minute without stopping.

Stress as a biological process Stress affects people in different ways, depending on the severity and intensity of the stressor, the type of stress response, the duration of the response and the individual involved.

Fight-Flight-Freeze Response What is the fight-flight response? What systems are involved in this response? Why do you think the ‘freeze’ has been added to the response? https: //www. youtube. com/watch? v=j. EH w. B 1 PG_-Q

Fight-Flight-Freeze The fight-flight-freeze response is an Response involuntary physical response to a sudden and immediate threat (or stressor) in readiness to: fight - confronting and fighting off the threat flight - escaping by running away to safety freeze - keeping absolutely still and silent

Fight or Flight Primitive response. Response to stress. When a situation is interpreted as threatening, you are given the options to confront it (fight), or flee from it (flight). Innate process which prepares us to take on the situation or run from it. Your body hits you with adrenaline in a stressful situation that gives you the choice to fight, or run away (flight).

Fight or Flight Response

Fight or Flight and the brain 1. Threat perceived 2. Hypothalamus (gland) activates the sympathetic NS 3. SNS stimulates the adrenal medulla (inner part of adrenal glands) 4. Hormones secreted into bloodstream known as adrenaline and noradrenaline (stress hormones) 5. These stress hormones circulate in the bloodstream and activate various organs including the heart, lungs, liver, resulting in the physiological reactions that characterise the fight-flight response. 6. When threat is removed PNS restores body and adrenaline and noradrenaline fall back to pre-treat levels. Place this information into your flowchart

Freeze Reactions Sometimes the stressor is so overwhelming that there is little or no chance of fighting or fleeing. This is when we may go into a freeze state - unable to move. What do you think happens with our physiological systems in this reaction?

Freeze reactions This apparent frozen state is called tonic immobility. This is thought to have adaptive value, especially among animals - why?

Freeze Reactions In some cases, freezing when fearful is not adaptive. For example… Biological processes underlying the freeze response are not completely understood. It is believed that the sympathetic and parasympathetic nervous systems are both highly aroused resulting in both energy conservation and a mobilised state ready for action.

The HPA Axis If the threat is not removed or needs to be dealt with over time (chronic) then additional physiological responses like the activation of the HPA Axis are needed. HPA stands for Hypothalamicpituitary-arenocortical axis

1. Higher brain, cortex etc The pituitary-adrenal system (HPA) 2. Hypothalamus 3. Pituitary gland 4. Adrenal cortex …involves responses from a number of different body systems and structures

The hypothalamic-pituitary-adrenocortical axis (HPA)

HPA Axis 1. The hypothalamus is in charge of the stress response… 2. When a stress response is triggered, it sends signals to the pituitary gland… 3. When the pituitary gland is activated it releases 4. ACTH, this activates the adrenal cortex… 5. The adrenal cortex releases further hormones into the bloodstream called corticosteroids - predominantly CORTISOL

To role of cortisol The main effect of cortisol is to energise the body by increasing energy supplies. It also has anti-inflammatory effects by blocking the activity of white blood cells. It slows the activity of the immune system as part of the overall process of targeting essential bodily resources to ensure instantaneous fight-flight and freeze reactions.

HPA Axis - Main Concerns Prolonged activation of these stress response systems can be harmful to our body Long term activation of the HPA Axis causes cortisol to remain in our bloodstream at a high level. This impairs our immune system making us vulnerable to diseases.

Reflection and Homework Stress bingo! Complete learning activity 3. 12 (ALL). On the blog, describe a fight -flight-freeze reaction you have experienced and the physiological changes of which you were aware of and any you were unlikely to be aware of.