Neurobiology Of Stress Summary Flashcards
(23 cards)
What is the basic definition of Stress?
Stress is a non-specific response of the body to any demand placed on it.
What are the three layers of meaning of stress?
- Stressor: The threat to balance (e.g. cold, exams, trauma)
- Stress Response: Your body’s reaction (e.g. increased heart rate, cortisol)
- Stress Condition: The internal state (e.g. tension, fatigue, burnout)
What are the types of stressors?
- Physical: Injury, exercise, temperature changes
- Physiological: Oxygen, glucose, pH imbalances
- Emotional: Anxiety, isolation, social pressure
What does the SAM system stand for?
Sympathetic-Adrenal-Medullary system
What is the main function of the SAM system?
Triggers the ‘fight or flight’ response.
What hormones are released by the SAM system?
- Adrenaline
- Noradrenaline
What is the HPA axis?
Hypothalamus → Pituitary → Adrenal Cortex
What hormone is primarily released by the HPA axis?
Cortisol
What are the three stages of General Adaptation Syndrome (GAS)?
- Alarm Stage
- Resistance Stage
- Exhaustion Stage
What happens during the Alarm Stage of GAS?
Initial response: SAM activated, surge in adrenaline and noradrenaline.
What occurs during the Resistance Stage of GAS?
Body tries to adapt and cope; HPA axis is active, cortisol rises.
What characterizes the Exhaustion Stage of GAS?
Resources depleted; high cortisol levels weaken immune system, damage neurons.
What are the main hormones involved in hormonal control during stress?
- Adrenaline
- Noradrenaline
- Cortisol
What brain regions are involved in neuronal control during stress?
- Hypothalamus
- Hippocampus
- Amygdala
- Prefrontal cortex
True or False: Short-term stress can stimulate neurons and improve focus.
True
What are the effects of long-term (chronic) stress on neurons?
- Damages neurons in the hippocampus
- Causes dendritic atrophy
- Impaired neuroplasticity
What is epigenetics?
Chemical tags on DNA that turn genes on or off without changing the DNA sequence.
What are the key mechanisms of epigenetics?
- DNA methylation: silences genes
- Histone modification: tightens or loosens DNA coils
How does early life stress (ELS) affect gene expression?
Changes the expression of stress-related genes, making someone more reactive to stress later in life.
What are some long-term effects of children exposed to chronic stress?
- Smaller hippocampus volumes
- Higher cortisol levels
- Greater risk of PTSD, depression
Fill in the blank: The main stress hormone is _______.
Cortisol
What are glucocorticoids?
Steroid hormones (like cortisol) involved in the stress response.
What is neuroplasticity?
The brain’s ability to adapt and reorganize.
