Stress response system Flashcards
(55 cards)
What is Homeostasis?
Examples:
- self regulating biological systems that allows organisms to survive and adapt to environments
- Body temp ( sweating)
- Blood Pressure ( When BP rises, blood vessels open more which slows heart rate and returns blood pressure to normal.
- Food - When you’re hungry, you eat. If you have less food, your body adjusts to a slower metabolism rate.
Why is Homeostasis essential for bodily functions?
is essential for optimal functioning of the body.
It allows the body to maintain conditions that are ideal for enzyme action and cell functions.
what would happen if homeostasis wasn’t a thing?
Without homeostasis, cells would quickly die when there aren’t enough nutrients
what did Hans Selye (1936) do?
General adaptation syndrome
- Injected rats with sex hormone
- Peptic ulcers, enlarged adrenal glands, involution of immune tissues
-Is this a result of the sex hormone? NO= same physiological responses rats injected with other chemicals and physical restrain
Same changes happened in the follow up study with other chemicals
why does heart beat (homeostasis) change during exercise?
- to get oxygen around body specifically muscles
what does repeated or chronic stress lead to?
to common diseases of modern life
what can stress be defined as?
Stress can be defined as events that are threatening to an individual and which elicit physiological and behavioral responses
What is Allostasis?
active process that leads to adaptation to a stressor
Exposed to a new situation - change average stress point to a new one to adapt to new condition and once new condition goes away system is back to average point
what is the autonomic nervous system
‘fight or flight’
what are the divisions of the autonomic nervous system?
sympathetic and parasympathetic
what is the first system triggered with stress?
Autonomic nervous system
What role do adrenaline and noradrenaline play in the body’s response to stress?
They act as neurotransmitters that make the heart work faster, preparing the body for action.
play a crucial role in fight or flight system
adrenaline plays a crucial role in action potential
what are the two major systems orchestrating the stress response?
Hypothalamic-pituitary-adrenal axis and autonomic nervous system
which limbic structures regulate HPA axis?
Prefrontal cortex, hippocampus and amygdala
Where are adrenaline and noradrenaline primarily released from?
Adrenal medulla
effects of acute stress
Acute stress has effects in the immune system by mobilizing the lymphocytes
(natural killer cells)
anti inflammatory effects
what does the hypothalamus release in response to stress?
corticotropin-releasing hormone
what does the anterior pituitary release?
adrenocorticotropin hormone
where is cortisol released?
Adrenal Cortex
where is adrenal gland located?
Above kidneys
How does the autonomic nervous system contribute to the release of adrenaline?
Autonomic nervous system send messages to adrenal medulla which then releases adrenaline to prepare the body for a fast response
What is the autonomic nervous system mediated by?
neurons
why is autonomic nervous system considered a very fast system?
it is mediated by neurons, allowing an immediate response, such as increased heart rate and sweating when feeling anxious. or movement
Which hormones are involved in the HPA axis?
CRH (Corticotropin-Releasing Hormone), ACTH (Adrenocorticotropic Hormone), and Cortisol.