11.1.1 Anxiety Flashcards
What is the physiological role of anxiety?
Stress response to enable us to escape from potentially dangerous situations
What is the stress response primarily mediated by?
Limbic system
What are the neural and endocrine targets of the stress response?
Neural
-Hippocampus
-Amygdala
-Prefrontal cortex
Endocrine
-Hypothalamus
Outline the effects on the hippocampus in the stress response
-Receives inputs from many parts of the cortex and processes emotional content
-Projects to thalamus (then to cortex-papez circuit) and hypothalamus
-Role in memory
Why does the hypothalamus cause autonomic features of emotional response?
Hypothalamus sends projections down through cord to autonomic preganglionic neurones- hypothalamospinal tract
Leads to sympathetic nervous system activation and release of adrenaline from adrenal medulla- acute stress response
Outline the effects on the amygadala in the stress response
Receives many inputs from sensory system
Major outputs to cortex and hypothalamus
Involved in behavioural and autonomic emotional responses
Outline the effects on the prefrontal cortex in the stress response
Modulation of emotional responses (you consciously suppress features of anxiety)
What is the response of the hypothalamus to stimulation from the limbic system in the stress response?
Acts via HPA axis
Release of cortisol from fasciculata layer of the adrenal cortex
What is general adaptation syndrome?
Refers to the three stages the body goes through during prolonged exposure to stressors
Stage 1- The Alarm Reaction
Stage 2- Resistance
Stage 3- Exhaustion
What happens in stage 1: the alarm reaction?
Release of adrenaline and cortisol as well as sympathetic activation
What happens in stage 2: resistance?
Adrenaline effects wear off
Chronic stress response, prolonged release of cortisol
What happens in stage 3: exhaustion?
Cannot escape an ongoing stressor
Chronic side effects of prolonged cortisol secretion start to occur
When does the stress response become pathological?
Unable to escape a stressor
or
When trivial stressors elicit a strong stress response
Patients with anxiety disorders may go through all of the stages
What is anxiety?
Pathological stress response
What are the symptoms of anxiety due to?
Sympathetic activation
