Autonomic Nervous System (18)

Question 1

What is the ANS?

Answer 1

> The motor subdivision of the PNS that controls the body’s automatic activities
Composed of specialised group of neurones that regulate cardiac muscle; smooth muscle in the walls of visceral organs; blood vessels; glands
Homeostasis depends largely on the workings of the ANS
Also called “Involuntary Nervous System”

Question 2

What are the divisions of the ANS?

Answer 2

> Sympathetic and parasympathetic

> Act together to keep the body running smoothly

Question 3

What is the parasympathetic nervous system?

Answer 3

> 'Rest and Digest' 
> Keeps body energy use low 
> Most active when body is at rest and not threatened 
> Involves the 'D' activities- digestion, defaecation and diuresis 
> e.g. person relaxing after a meal:
   - BP, HR and RR low 
   - GI tract activity is high 
   - Warm skin and constricted pupils

Question 4

What is the sympathetic nervous system?

Answer 4

> ‘Fight or Flight’
Most active when we are in emergency/ threatening situations
Involves ‘E’ activities- exercise, excitement, emergency and embarrassment
Promotes adjustments during exercise- blood flow to organs reduced, and flow to muscles is increased
e.g. when person is threatened:
- HR increases, breathing rapid and deep
- Skin cold and sweaty and dilated pupils

Question 5

What is the ‘Fight or Flight’ mechanism?

Answer 5

> Provides optimal conditions for an appropriate response to threat, whether that is running, seeing more clearly or thinking more critically
Pounding heart, rapid deep breathing, dilated pupils, changes in brain wave pattern, changes in galvanic skin resistance
Vasoconstriction in cutaneous (skin) and visceral (internal organ) blood vessels
Vasodilation in myocardial and skeletal muscles
Nutrients mobilised from liver (glycogen) to raise glucose levels
Non-essential activities such as GI and urinary motility are reduced

Question 6

What is the definition of stress?

Answer 6

‘A situation where demands on a person exceed that person’s resources or ability to cope’- Stress management society

Question 7

What is involved in the stress response?

Answer 7

> Includes intellectual, behavioural and emotional components, decision making, withdrawal and anger, major part is physiological
CNS
Hypothalamus
Sympathetic nervous system
Anterior and posterior pituitary gland
Adrenal medulla (A and NA) and adrenal cortex (cortisol)

Question 8

What is eustress?

Answer 8

> A certain amount of stress is good as it acts as a motivator and can enhance performance

Question 9

What is eustress?

Answer 9

> A certain amount of stress is good as it acts as a motivator and can enhance performance

Question 10

What is distress?

Answer 10

After a certain point, stress has a negative effect and our performance drops off

Question 11

What is distress?

Answer 11

After a certain point, stress has a negative effect and our performance drops off

Question 12

What is distress?

Answer 12

After a certain point, stress has a negative effect and our performance drops off

Question 13

What can understanding stress lead to?

Answer 13

> Identifying individuals at risk of inability to deal with stressors
Recognition of how prolonged/ repeated stress can result in disease
Understanding of how the neuroendocrine component of the stress response can eventually become a threat to health

Question 14

What is the acute response?

Answer 14

> Short-lasting
Initiated by sympathetic nervous system activity and secretion of catecholamines (A, NA and dopamine) from the adrenal medulla

Question 15

What is the slow stress response?

Answer 15

> Longer-lasting (slower to start and slower to dissipate)

> Caused mainly by action of glucocorticoid hormones from the adrenal cortex

Question 16

What are 3 theories of stress?

Answer 16

1) Stress as a stimulus (Cox 1978)
2) Stress as a transaction (Lazarus 1966)
3) Stress as a response (Selye 1956)

Question 17

What is Selye’s theory?

Answer 17

> Concerned with bodily psychophysiological responses to environmental stressors
Sources of stress can be environmental or social and they can be exogenous (outside) or endogenous (inside)
‘Stress is the non-specific response of the body and that freedom from stress is death’
Developed concept of the General Adaptation Syndrome (GAS) to discuss the 3 stages of stress- alarm reaction; resistance stage; exhaustion stage

Question 18

What is the alarm stage?

Answer 18

> Predominantly initiated and controlled by the sympathetic nervous system
Affects visceral motor organs such as the brain, heart and skeletal muscles
Initial sympathetic effects are prolonged by simultaneous release of catecholamines
Effect of alarm stage is a short-term homeostatic control to enable adaptation/coping
Progress (returning to homeostasis) depends on person’s perception of stress, duration of the demand and their coping mechanisms

Question 19

What is the resistance stage?

Answer 19

> Controlled predominantly by the endocrine system, especially hypothalamus
We have limited amount of adaptation energy and every stressor leaves signs of ‘wear and tear’
Homeostasis is restored- if adaptation energy is depleted, may move into next stage

Question 20

What is the exhaustion stage?

Answer 20

> Signs of alarm stage reappear as adaptation energy runs out and homeostasis fails
Stress related illnesses appear
Selye describes; diseases of adaptation leads to death

Question 21

What are some physical indicators of stress?

Answer 21

> Hypertension
> Tachycardia
> RR increases 
> Loss of appetite
> Insomnia  
> Nausea

Question 22

What are some behavioural indicators of stress?

Answer 22

> Poor work performance 
> Forgetfulness
> Social isolation 
> Loss of interest
> Smoking/alcohol

Question 23

What are some emotional indicators of stress?

Answer 23

> Crying
> Irritability
> Hostility
> Anxiety
> Depression