The Endocrine System and Fight or Flight Flashcards
Outline the endocrine system.
A series of ductless glands which secrete chemicals (hormones) throughout the body via the bloodstream.
What are the bodies two communication systems?
The nervous system and the endocrine system.
Compare the nervous system to the nervous system.
Nervous system: faster, shorter span time, uses nerves, controls directly.
Endocrine system: slower, long span time, uses blood, controls indirectly.
How is the fight or flight response activated?
When your ANS needs changes itself from a resting stage (parasympathetic state) to the physiologically aroused (sympathetic state).
When the fight or flight response is triggered. Adrenaline is also triggered. Briefly outline the process.
Hypothalamus releases a hormone to trigger activity in the sympathetic nervous system.
The sympathetic branch stimulates the adrenal medulla and this secretes adrenaline and noradrenaline into our bloodstream.
These hormones trigger physical effects on the body.
What is the adrenal medulla?
Part of the adrenal gland that sits just on top of the kidney
What does SAM stand for? What is it?
Sympathetic Adrenal Medullary Pathway.
The initial shock response.
Outline SAM, as a response to fight or flight being activated.
Activity in the sympathetic branch of the ANS stimulates the adrenal medulla, which forms part of the adrenal glands.
The adrenal medulla secretes the hormones adrenaline and noradrenaline.
These hormones lead to increased arousal of the sympathetic nervous system and reduced activity in the parasympathetic nervous system.
E.g. increased heart rate, increased breathing rate, decreased salivation.
What does HPAC stand for? What is it?
Hypothalamic-Pituitary-Adrenocortical Axis.
A counter-shock response designed to minimise any damage that may be caused.
If exposed to a stressor for several hours or more, this pathway will kick in - otherwise SAM will use up bodily resources.
Outline HPAC, as a response to fight or flight being activated.
Hypothalamus releases hormones (e.g. corticotrophin-releasing factor) that stimulates the anterior pituitary gland.
The anterior pituitary gland secretes the adrenocorticotrophic hormone.
Adrenocorticotrophic hormone stimulates the adrenal cortex.
Adrenal cortex produces various glucocorticoids such as cortisol (the ‘stress’ hormone).
This has an effect on glucose metabolism.
Outline 3 physiological response to the fight or flight response.
Increases in blood pressure and heart rate = increases oxygen supply in muscles.
Decreased digestion = allows more oxygenated blood to be focused to working muscles.
Muscles tensing = preparation for movement/ contraction.
Perspiration increases = releases heat (evaporation).
Breathing rate increases = more oxygen available.
Pupils dilate = more light able to enter pupils, allowing the host to see more efficiently .
Salivation decreases = allows more oxygenated blood to working muscles.
Increased the release of clotting factors into the bloodstream = better healing response to injury.
