AUTONOMIC NERVOUS SYSTEM Flashcards
describe the ANS?
the motor subdivision of the peripheral nervous system which automatically controls the body’s activities using neurones.
the stability of the internal environment depends on the workings of the ANS
what is another name for the ANS?
the involuntary nervous system
name and describe the two divisions of the ANS?
sympathetic nervous system- mobilises the body in extreme situations e.g. fear, exercise
parasympathetic nervous system- maintenance activities and conserves the bodies energy
name the hormones of the sympathetic NS?
adrenaline (epinephrine)
noradrenaline
where are the hormones of the sympathetic nervous system released from?
the adrenal medulla of the adrenal (suprarenal) gland
describe the role of the parasympathetic division?
keeping energy use low, most active during rest
*D activities = digestion, defecation, diuresis
list some examples of the parasympathetic nervous system?
reduce BP reduce HR stimulates salivation pupils constrict stimulates digestive activity
describe the role of the sympathetic division?
responsible for fight or flight, such as during exercise of when threatened
*E activities = exercise, excitement, emergency, embarrassment
list some examples of the sympathetic nervous system?
increase HR
increase BP
pupils dilate
inhibits digestion
outline the fight or flight response?
- provides optimal conditions for the appropriate response to threat such as:
- dilated pupils, rapid breathing, pounding heart, changes to brain wave pattern and galvanic skin resistance
- cutaneous and visceral blood vessels constrict
- vasodilation in myocardial and skeletal muscle (broncho-dilation)
- nutrients mobilised from liver= increase glucose levels
- non essential activities e.g. GI and urinary motility reduced
what is the stress response?
a function of the central nervous system, including the hypothalamus, adrenal medulla/cortex, sympathetic and parasympathetic nervous system
describe stress?
me.
situation where demands exceed the persons recourses to cope
the major part of stress is physiological
how can understanding stress help?
can identify individuals at risk of inability to deal with stressors
recognise how prolonged/ repeated stress results in disease
understand how neuroendocrine component of stress can result in a threat to health
what is eustress?
the stress which helps to motivate us and enhances our performance
too much stress has a negative effect and performance drops off (distress)
outline the acute response to stress?
short lasting
initiated by SNS activity and secretion of catecholamines from the medulla (adrenaline and noradrenaline, dopamine)
outline the slow stress response?
longer lasting and slower to start and dissipate
caused mainly by action of glucocorticoids from the adrenal cortex (cortisol)
name 3 theories of stress?
stress as a stimulus (Cox 1978)
stress as a transaction (Lazarus 1966)
stress as a response (Selye 1956)
describe Selyes theory?
- concerned with bodily psychophysiological response to environmental stressors
- sources can be outside (exogenous), inside (endogenous), environmental or social
- Selye- “stress is a non-specific response of the body”
- GAS- general adaptation syndrome consisting of alarm reaction, resistance and exhaustion
describe the alarm stage of GAS?
initiated and controlled by the SNS, affecting the visceral motor organs, brain, heart and muscle
aims to stimulate short term homeostatic control to enable adaptation/ coping
progress dependant on perception of stress, duration of demand and coping mechanisms
describe the resistance stage of GAS?
controlled by the endocrine system, especially the hypothalamus
we have limited adaptation energy since all stressors leave signs of wear and tear
either homeostasis is restored or out energy is depleted
describe the exhaustion stage of GAS?
signs of the alarm stage reappear as energy runs out and homeostasis fails
stress related illness may occur (“diseases of adaptation”)
list the physical indicators of stress?
hypertension tachycardia increased respiratory rate increased muscle tension upset stomach decreased appetite indigestion insomnia headache nail biting nausea
list the behavioural indicators of stress?
accidents smoking alcohol decreased interest mental block daydreaming forgetfulness family breakdown social isolation
list the emotional indicators of stress?
crying irritability depression tiredness anxiety blaming others hostility emotional outbursts
