When looking at stress, you can understand the biological component of the biopsychosocial framework by talking about:
1) Hans Selye's General Adaptation Syndrome (GAS) which is the 3 stage physiological stress response that occurs regardless of the stressor that is encountered and is related to how the individual copes with the stressor at a physiological (or bodily) level. So, the GAS is non-specific (it always occurs regardless of the stressor) and is composed of ARE stages (Alarm-Reaction, Resistance, Exhaustion)

2) You might also be able to talk about the fight-flight response as a physiological response that activates in response to immediate stressors or threats and the physiological changes that occur to enable a person to either confront the stressor directly ("fight") or flee from it ("flight"). Because the fight-flight response involves activation of both the endocrine and sympathetic nervous systems through activation of bodily functions such as increased heart rate, expanding of bronchioles, increased access of glucose to muscles, and secretion of adrenaline and potentially cortisol (if the stressor is enduring).
3) Allostasis is the body's ability or extent to which it can keep its functions stable in times of stress (similar to homeostasis) and ensures that people can "bounce back" or show resilience after having encountered a stressor in their life.
4) You can also discuss the HPA axis (Hypothalamus-Pituitary Adrenal) which is the physiological reaction to stress that involves activation of the Hypothalamus, Pituitary and Adrenal glands. As soon a stressor is recognised by the individual, their hypothalamus is activated. The hypothalamus then goes on to activate the pituitary gland and this causes secretion of ACTH. This ACTH then stimulates the adrenal glands to secrete adrenaline and noradrenaline (which are known as the "stress hormones" and thus boost the sympathetic nervous system action (and the associated physiological functions of the fight-flight response) as well as releasing cortisol to increase metabolism and increase the level of glucose available to the muscles.
Hope this helps!
