The Nervous System and Fight or Flight response Flashcards
What does the central nervous system consist of?
The brain and spinal cord
What is the role of the CNS?
Central control for all activities of the body, where information received is processed and there is coordination of actions and reactions, both conscious and unconscious - decision making and coordination
What does the PNS consist of?
A network of neurons which are located around the whole body and are responsible for carrying information from the world to the CNS and from the CNS back to the different parts of the body
What principle do both branches of the PNS operate on?
Homeostasis
What are the subdivisions of the PNS?
Somatic nervous system, autonomic nervous system
What does the somatic nervous system consist of?
Two types of neurons:
Motor neurons - carry information about movement out of the brain
Sensory neurons - carry sensory information in to the CNS, allow us to experience pain, pressure and changes in temperature.
What is the role of the autonomic nervous system?
Controls automatic and self regulating activities which continues whether a person is asleep or unconscious
Where do the nerves of the ANS run to and from?
Internal organs and glands
What are the two branches of the ANS?
Sympathetic and parasympathetic
What is the role of the sympathetic branch?
Speeds up bodily systems and prepares the organism for activity, such as ‘fight or flight’. Distributes the release of noradrenaline so it is excitatory
What is the role of the parasympathetic branch?
Responsible for returning the body to normal by slowing it down again and allowing bodily functions to return to their original state - so it is inhibitory
Give 3 effects of noradrenaline on the body
Dilates pupils
Increases heart rate
Dilates airways
What is the body’s response to acute stress?
The sympathetic adrenal medullary (SAM) pathway
Outline what happens in the SAM pathway
Hypothalamus (which identifies threat) activates the ANS. This causes the adrenal medulla to release adrenaline and noradrenaline.
What is the body’s response to chronic stress?
The hypothalamic - pituitary - adrenal axis (HPA)
Outline what happens in the HPA response
Hypothalamus recognises stressor, activates pituitary gland which causes the release of ACTH (adrenocorticotropic hormone). This stimulates the adrenal cortex which releases cortisol and glucose.
What are the results of glucose and cortisol being released in the HPA response?
Glucocorticoids are released into the liver to release stored glucose
Effects include:
- heightened and maintainable energy supply
- lower pain sensitivity
- lower immune response
- high blood pressure
Evaluate the flight or fight response (females)
Doesn’t fully explain the stress response in females
Taylor et al (2002) - females adopt a ‘tend and befriend’. Women are more likely to protect their offspring and form alliances with other women rather than fight an adversary or flee.
This highlights a beta bias
However, this has prompted more recent research which has provided an alternate explanation which is applicable to females
Evaluate the fight or flight response (health)
Can have a detrimental effect on health
While it may have been useful for our ancestors, modern day life rarely requires such an intense biological response.
This matters because the activation of the fight or flight response can increase blood pressure and cause damage to blood vessels and contribute to heart disease.
This suggests that the FOF response is a maladaptive response in modern day life
Evaluate the fight or flight response (human behaviour not limited)
Human behaviour is not limited to just two responses
Gray (1988) - first response to danger is to avoid confrontation altogether, demonstrated by a ‘freeze’ response. During the freeze response, humans are hyper vigilant while they appraise the situation to decide the best course of action for that particular threat
This suggests that the fight or flight explanation of behaviour is limited and doesn’t fully explain the complex cognitive and biological factors that underpin the human response to stress / danger
