The Fight or Flight Response

Process of the Flight or Flight Response

Begins in the ANS - switch from resting PNS (parasympathetic nervous system) to the SNS (sympathetic nervous system). (1) The hypothalamus recognises a threat. Sends a message to - (2) The adrenal gland (Adrenal Medulla) Triggers release of - (3) Adrenaline to the endocrine system. Noradrenaline in the brain. Prompts physical changes: - Increased heart rate - Faster breathing rate - Muscle tension - Pupil dilation - Sweating - Reduced function of digestive and immune systems.

Adrenal Medulla

Central part of the adrenal gland.

Von Dawans et al (2012)

Challenges view that only men respond with 'fight or flight' and women with 'tend and befriend'. Acute stress can actually lead to more cooperative and friendly behaviour in both sexes. e.g. human connection that takes place in crisis such as the 9/11 terrorist attacks. Humans are fundamentally social animals and it is the protective nature of human social relationships that has allowed our species to have survived.

"Tend and Befriend" response

Criticism of fight or flight. Females may display a different pattern to males - involves protecting themselves and their young through nurturing behaviours (tending). Forming protective alliances with other women (befriending). Evolved as PCG of offspring. Fleeing too readily will leave offspring at risk. Study of rats suggests there may be a physiological response that inhibits flight - the release of oxytocin which increases relaxation, reduces fearfulness and decreases stress response.

Negative consequences

Criticism of fight or flight. Stressors of modern day life don't generally need such a physical reaction. When repeatedly actively can lead to damage. e.g. too much cortisol can lead to the suppression of the immune response, shutting down the process that fights infection.

Gray (1988)

Fight or flight doesn't tell the whole story (criticism). First phase of the reaction is to avoid confrontation. Prior to attacking or running there is a "freeze-response". Hyper vigilant, alert to the slightest sign of danger. Freezing focuses attention and causes animal to look for new information in order to make the best response for that particular threat.

Lee and Harley (2012)

Gentic basis to gender differences. SRY gene found on male Y chromosone. Promotes aggression and results in the fight or flight response. SRY gene primes males to respond this way due to hormone release such as adrenaline. Absence of SRY gene in females together with action of oestrogen and oxytocin may prevent this stress response.

Adrenaline

Hormone produced by the adrenal glands which is part of the human body's immediate stress response system. Has a very strong effect on the cardiovascular system: - Stimulates heart rate. - Concentrates blood vessels. - Dilates air passages.

Faster breathing rate

Improves oxygen intake.

Muscle tension

Improves reaction time and speed.

Pupil dilation

Improves vision.

Hypothalamus

Located in centre of the brain. Deals with basic survival function and the release of hormones.

Sweating

Regulates temperature.

Reduced function of digestive and immune systems

Saves energy for prioritised functions such as running.

Increased heart rate

Speeds up blood flow to vital organs and improves the spread of adrenaline around the body.

Adrenal Gland

The gland in the adrenal system which releases adrenaline.

Fight or flight response

The way an animal responds when stressed. Body becomes physiologically aroused in readiness to fight or flee a predator. Thought to be an adaptive, evolutionary instinct to promote survival.