Hormones, Stress and the Brain- Week Five Flashcards
What is a hormone?
A chemical signal which is released into the bloodstream by an ‘endocrine gland’ which targets cells in other organs.
What are the features of a hormone?
Communication is slower and more generalised
Biologically vital for metabolism, reproduction and growth
Highly integrated with brain function
What are the features of the endocrine system?
Pineal gland
Hypothalamus
Ovaries/Testes
Adrenal Gland
What role does the pineal gland play
daily biological sleep cycles
What role does the adrenal gland play
involved in fight/flight and metabolism
What role does the hypothalamus play
important in regulating sleep and appetite
What role do the testes/ovaries play
sex hormones
What is stress?
general imprecise term referring either to the stress response or to a stressor
What is a stressor?
A stimulus or situation that produces a stress response
What is a stress response?
A physiological reaction cause by perception of aversive threatening situation
What are the 2 phases of the stress response?
Autonomic nervous system and hormonal
What are the fast autonomic responses?
Heart: increased h/r Lungs: widens bronchioles Gut: stops activity Skin: hair stands on end Adrenal Gland
What do the adrenal glands do in the stress response?
They secrete adrenaline and noradrenaline in response to hormonal output and sympathetic innervation
What are the actions of adrenaline and noradrenaline?
Increased heart rate, increased oxygen uptake, diverts blood from gut to muscles, increased glucose in blood, increases breakdown of stored energy
What is the role of cortisol in a stress response?
Also secreted from adrenal gland, under control from hypothalamus and pituitary gland
Makes more energy by breaking down fats and affecting glucose metabolism
What type of hormone is cortisol?
A glucocorticoid hormone
Stress and blood pressure:
Hypertension- high b/p
Links to high cortisol release and fertility problems and diabetes
Stress and healing
longer time to heal due to cortisol inhibiting inflammatory response
Stress and immune system
Immune system is poorer when stressed
Stress and prenatal
cortisol affects unborn infants, they have a stronger response later in life
What is P.T.S.D?
Can follow exposure to extreme events: e.g warzone
What are the symptoms of P.T.S.D?
Recurrent dream
Flashbacks
Social interactions
Depression
What other factors can play a role in P.T.S.D?
Genetic factors
What is the purpose of stress?
Despite having an active effect on health, it helps us to deal with stressful situations; to help keep us safe.
Not having adrenal glands would lead to death, moderate stress is part of out natural homeostatis
