Endocrine system: Stress response Flashcards
Label the diagram
Label the diagram
What is the purpose of the hypophyseal portal veins?
It is how the hypothalamus communicates with the anterior pituitary as they hypothalamus releases chemicals into it which go directly to the anterior pituitary
How many different types of hormones does the hypothalamus and pituitary produce?
9 and 7
What is the function of the pituitary gland for stress response?
Controls the adrenal glands
What is the function of the adrenal glands?
Enhances the alarm response
What are the two parts of the adrenal gland?
The adrenal medulla (inner) and adrenal cortex (outer)
What are the hormones that are released by the adrenal gland?
Adrenal medulla: Epinephrine and norepinephrine
Adrenal cortex: Mineralocorticoids (i.e. aldosterone) and Glucocorticoids (i.e. cortisol)
What is the release of the hormones in the adrenal medulla stimulated by?
ACh from the sympathetic pre-ganglionic neurons
What is the release of hormones in the adrenal cortex stimulated by?
Mineralocorticoids: increased K+ and angiotensin II (causes increase in blood pressure FYI) in the blood
Glucocorticoids: ACTH (Adrenocorticotropic hormone) from the pituitary which is stimulated by CRH (Corticotropin-releasing hormone) from hypothalamus
What is the function of the epinephrine and norepinephrine released by the adrenal medulla?
Enhances and sustains the sympathetic autonomic alarm response
What is the function of the mineralocorticoids released by the adrenal cortex?
Increase blood Na+ and water amounts and decreases blood K+ leading to increased blood volume and pressure
What is the function of the glucocorticoids released by the adrenal cortex?
Initiates resistance reaction, dampens inflammation and shift immunes response to be better at fight short term risks (i.e. infection fighting cells boosted over cancer fighting cells)
Label the diagram, what is it showing?
This is showing a negative feedback loop for the production of cortisol which is activating the resistance reaction
What are the actions of the resistance reaction caused by cortisol?
Know at least 3 of these
Protein breakdown: Increased protein break down mainly in muscle fibres for synthesis of new proteins and ATP production
Gluconeogenesis: Liver cells start producing glucose from amino acids, lactic acid etc.
Lipolysis: Breaking down of triglycerides and releasing fatty acids into blood
Vasoconstriction: Blood vessels become more sensitive to hormones that cause vasoconstriction = increasing blood pressure
Anti-inflammatory: Inhibit white blood cells that cause inflammatory response to limit damage to these cells
What is a consequence of the anti-inflammatory response caused by cortisol?
It retards tissue repair and slows wound healing
How can cortisol in high concentrations be used?
Used to depress immunes response post organ transplants to prevent transplant rejection
What are the two stages of the stress response?
Alarm response (first stage) and the resistance reaction (second stage)
What are the actions involved in the Alarm response?
Immediate action, sympathetic activation and adrenal medulla involvement (release epinephrine and norepinephrine to sustain the sympathetic activation)
What is the purpose of the resistance reaction?
Slower and longer lasting cortisol production involved in countering the damage caused by the fight or flight response
Explain the pathway of the alarm response
1 - Sympathetic nerves activate the adrenal medulla
2 - Adrenal medulla secretes epinephrine and norepinephrine into the blood stream
3 - Epinephrine and norepinephrine cause the alarm responses in all organs of the body and prolongs them
Explain the pathway of the resistance response
1 - Neurosecretory cells release CRH (Corticotropin-releasing hormone) into primary hypophyseal portal system to the anterior pituitary
2 - Anterior pituitary release ACTH (Adrenocorticotropic hormone) into blood stream
3 - ACTH stimulates adrenal cortex to produce cortisol
4 - Negative feedback loop of cortisol invoked (i.e. high cortisol inhibits CRH and ACTH secretion)
How do the neuroendocrine and immune systems interact?
Autonomic nerves and hormones form the neuroendocrine system influence the immune system and cytokines influence the neuroendocrine system
What are cytokines?
Proteins that are involved in autocrine signalling, paracrine signalling and endocrine signalling
What does our stress response allow us to do?
Allows humans to respond to short term physical and emotional stresses
What are the two types of stress?
Eustress and distress
What is eustress?
Positive stress response that quickly prepares us to physical responses
What is distress?
Negative stress response caused by a prolonged stress response
What is eustress positive and distress negative?
- Eustress allows for short term physical responses which are essential for our survival (i.e. increased alarm response for an immediate danger)
- Distress is when the short term changes of the alarm response are prolonged which cause harmful effects on the body (i.e. hypertension, illness…)
