The Endocrine System and Fight/Flight Response Flashcards
Hormones
Chemicals that are produced by glands of endocrine system
Upon the brain’s signal - hormones are secreted into the bloodstream and travel to ‘target cells’. The hormone then exerts an influence on the target cell by stimulating receptors on the surface of / or inside the cell
What are the regulatory functions of hormones?
Metabolism
Development
Tissue function
Sexual function
Reproduction
Sleep
Mood
Where are glands found?
The endocrine system
ACTH
Triggers the adrenal gland to release corticosteroids, resulting in a stress response.
What do hormones do?
Provides a chemical system of communication through the blood stream which each type of hormone targeting specific organs and tissues
What are three key glands in the endocrine system?
Pituitary gland
Adrenal gland
Thyroid gland
Pituitary gland
Helps regulate the function and secretion of other glands in the endocrine system. The master gland
Releases prolactin (helps lactation)
Adrenal gland
Secretes adrenaline and responds to the sympathetic division during fight or flight response
Thyroid gland
Secretes thyroxine which regulates metabolism rate and growth
Two divisions of the autonomic nervous system:
Sympathetic branch
Parasympathetic branch
When we perceive a stressor
The brain activates the sympathomedullary pathway which causes physiological changes in the body ~ ‘fight or flight response’
What occurs in the sympathomedullary pathway?
~ a stressor is perceived and a threat is assessed
~ the hypothalamus activates the sympathetic branch of the autonomic nervous system
~ sympathetic nerves transmit the signal from the CNS
~ the adrenal medulla releases adrenaline and noradrenaline into the bloodstream
~ adrenaline constricts blood vessels in the skin to divert blood to the muscles
Where is adrenaline and noradrenaline released from?
The adrenal medulla
What does adrenaline do in the sympathomedullary pathway?
Constricts blood vessels in the skin to direct blood to the muscles
Does adrenaline increase or decrease heart rate? And why?
Increase
Speeds up the blood flow so muscles can get more energy
Does adrenaline increase or decrease blood pressure? And why?
Increase
Speeds up blood flow around the body
Does adrenaline increase or decrease lung function? And why?
Supplies more oxygen
Does adrenaline increase or decrease blood glucose? And why?
Increase
For energy and respiration
Does adrenaline increase or decrease pupil size? And why?
Increase
To let more light in in order to see clearer and more
Does adrenaline increase or decrease blood flow to muscles? And why?
Increase
To increase mobility
Does adrenaline increase or decrease salivation? And why?
Decrease
Because digestion is not prioritised during fight or flight
Does adrenaline increase or decrease digestion? And why?
Decrease
Because blood is being directed to the muscles
What is the parasympathetic response?
~ once the threat of a stressor is gone, the autonomic nervous system switches from the activation of the sympathetic branch to the parasympathetic branch
~ reduces release of adrenaline into bloodstream
~ calming effect on the body ~ “rest and digest response” ~ decrease in heart rate and return of digestive processes
- parasympathetic activation returns to the body as a balanced state ~ homeostasis
Where are the adrenal glands located?
At the top of each kidney
Adrenal cortex
Secretes cortisol
Adrenal medulla
Secretes adrenaline
Limitation of our understanding of the fight or flight response:
That the human behaviour is not limited to two responses during threatening situations
What did Gray (1988) argue about the fight or flight response?
That the first response to danger is often to ‘freeze’
What does the ‘freeze’ argument state?
That humans are hyper-vigilant and assess the situation carefully to decide on the best course of action
How is the ‘fight or flight’ response too restrictive?
It cannot fully explain the range of cognitive and biological influences on behaviour
And is therefore incomplete ~ reduces validity
What is a strength of our understanding of the ‘fight or flight response’?
The supporting evidence uses scientific methodology by operationalising arousal through levels of hormones which is an objective measure free from researcher bias
How is the research carried out in ‘fight or flight response’?
In controlled conditions that means the methods can be easily replicated.
Researchers can therefore test the reliability of these findings ~ increasing validity of the research and therefore our understanding of this phenomenon
