Psychology A4 - concept five - biological Flashcards
5. neurochemistry
what is neurochemistry?
-concerns activity of chemical substances in the nervous system
-psychologists are interested in how substances affect the functioning of he brain and how it influences our thinking, emotions and behaviour
hormones and the stress response: what is a hormone?
-‘chemical messenger’ produced within structures called glands
-several glands form a network called endocrine system
-example of endocrine gland = adrenal gland
-adrenal gland produce adrenaline into bloodstream
-travels around the body and affects any cells that have adrenaline receptors
hormones and the stress response: stress hormones
-some hormones = stress hormones as they help to regulate and control body’s response to stress
-stress response = two phases – immediate (acute) and long term (chronic)
-involves different hormones
hormones and the stress response: stress hormones - adrenaline
-anything that causes stress = stressors
-when stressors occurs, body responds immediately with fight or flight response
-sympathetic division of ANS is activated and stimulates adrenaline to be released from adrenal glands
-adrenaline in bloodstream triggers physiological changes in body, indicate arousal
-examples, increased heart rate, pupil dilation etc.
hormones and the stress response: stress hormones - cortisol
-if stressor continues, body switches to long-term stress response
-cortisol = produced in adrenal glands
-some functions of cortisol help body cope with stressor
-example, it mobilises and restores energy supplies to keep it going
-however, cortisol has other effects that damage body
-example, it suppresses the immune system which is why people become ill during periods of chronic stress
neurotransmitters: what is a neurotransmitter?
-allow communication between nerve cells (neurons) in the brain and nervous system
-neurons = tiny cells not physically connected to each other but separated by gaps known as synapses
-use electrical signals at synpases but chemical substances pass signal on (neurotransmitters)
neurotransmitters: serotonin
-main neurotransmitters in nervous system
-been linked to a number of behaviours and disorders including depression
-thought that depression is associated with low levels of serotonin
-neurotransmitters are chemicals, activity can be altered by drugs
-example, antidepressants work by increasing levels of serotonin in synapses between neurons
evaluation: practical applications (+)
-understanding of stress hormones has practical value
-example, people with Addison’s disease cannot produce cortisol, bodies cannot mobilise energy to deal with chronic stressors
-lack of cortisol can trigger life-threatening Addisonian crisis (mental confusion etc) when stressor occurs
-if effective treatment, can give themselves cortisol replacement therapy (hydrocortisone)
-should be aware of stressful situations when they might need an ‘extra’ injection of hydrocortisone
-shows that a better understanding of stress response has improved lives of many
evaluation: research support (+)
-research showing importance of neurotransmitters and hormones
-example, serotonin plays an important role in stabilising moods, low levels links to depression (McNeal and Cimbolic, 1986)
-there is evidence in humans and animals that cortisol levels remain high during long-term stress and eventually cause damage and disorders like heart disease (Russell and Lightman, 2019)
-research suggests that neurochemistry plays a key role in regulating many behaviours
evaluation: incomplete explanation (-)
-neurochemistry doesn’t take psychological factors into account
-example, two people can experience same stressor but physiological responses differ, one remains calm, other experiences acute stress
-different occurs because people think differently about stressor
-one views it as an opportunity to show what they’ve learnt
-other views it as a disaster
-shows that neurochemistry isn’t a complete explanation of stress response because it neglects cognitive factors
