Fight or flight response
What does the flight or fight response include?
- Blood pressure and heart rate increases to get blood quickly to areas of the body where it's need for activity. - Digestion decreases so that blood can be directed to the brain and muscles. - Muscles become tense so body can cool down and burn more energy. - Breathing rate increases so more oxygen can be sent to the muscles.
What does HPA respond to?
It responds to chronic (on-going) stress and takes 20 minutes to complete process. System regulates itself to bring cortisol levels back to normal by reducing CRF and ACTH levels.
What does SAM respond to?
It response to acute (immediate) stress.
What does the SAM do?
It stimulate the adrenal medulla to release adrenaline and noradrenaline into the bloodstream. This leads to the flight or fight response.
What does the HPA do?
It stimulates the adrenal cortex to release corticosteroids, (cortisol) which helps to give us energy by facilitating the conversion of fat and protein.
What does the cerebral cortex do?
It transmits a signal to the hypthalamus
How is the hypothalamus linked to HPA?
The activation of the hypothalamus leads to the release of CRF into bloodstream. The CRF causes the pituitary gland to release a hormone called ACTH (adrenocorticotropic hormone) into the bloodstream.
What part of the brain evaluates whether something is a stressor?
The cerebral cortex
How is the SAM linked to the hypothalamus?
The hypothalamus activates the sympathetic branch of the Autonomic nervous system (ANS).
What processes does the Hypothalamus start?
The sympathetic-Adrenomedullary (SAM) system and the Hypothalamic Adrenal Adrenal Axis (HPA).