What is the endocrine system?
A system which focuses on the use of hormones to control vital functions in the body
What are hormones?
A chemical messenger secreted into the bloodstream and effects any cell in the body that has a receptor for that particular hormone
4 examples of glands
- Adrenal glands: responsible for metabolism and releases adrenaline
- Pituitary gland: master gland responsible for controlling the release of hormones for all the other endocrine glands
- Pancreas: controls blood sugar levels
- Thyroid gland: produces thyroxine which is essential for growth and brain development
Relationship of the endocrine system to the Autonomic Nervous System
- When a stressor is perceived, the hypothalamus triggers activity in the sympathetic branches of the ANS
- causes the change between the PsyNS and the SyNS
What is the flight or fight response?
A person’s response to a threatening situation where:
- the heart beats faster
- breathing becomes rapid
- muscles tense
What is the process of the fight or flight response?
- when facing a threat, the amygdala is mobilised
- the amygdala associates sensory signals with emotions associated with fight or fight
- the amygdala sends a distress signal to the hypothalamus which communicates to the rest of the body using the SyNS
Response to acute (sudden) stressors
- SyNS:
—> adrenal medulla releases adrenaline into the bloodstream
-> heart beats faster to push blood to vital organs and muscles
-> adrenaline triggers the release of glucose which is used for energy - PsyNS:
-> Heart rate decreases
-> blood pressure reduces
-> digestion begins again
Physical responses to fight or flight
- Heart: increased heart rate provides more blood to vital organs and muscles
- Liver stimulates glucose production which is used in respiration
- Eyes: pupils dilate to increase the visual field which can be taken in
- Lungs: bronchi dilate for greater oxygen absorption
:( negative consequences of fight or flight
- Is not adaptive for modern life, we no longer have predators
- Can lead to physical damage to blood vessels
:( Gender Bias: Taylor et al (2000)
Women’s behavioural response to stress and threats relate more to tend and befriend
- flight my put offspring at risk
- women have higher levels of oxytocin (love)
:( Gender Bias: Lee and Harley (2012)
SRY gene exclusively on the make Y gene chromosome promotes aggression relating to fight or flight
:( Gender Bias: Von Dalvan et al
Acute stress can lead to greater cooperative and friendly behaviour in both men and women.
Fight, flight, or freeze!
Gray (1988): first phase to avoid confrontation is to freeze
- freezing focuses attention and all allows you to look for newer information
