Definitions
1. Neurotransmitter: chemical messengers of the nervous system
2. Hormones: chemical messengers of the bloodstream and controlled by the endocrine system
3. Hippocampus: part of the brain associated with memory
4. Addison's disease: disease where the body does not produce enough cortisol resulting in wight loss, loss of appetite, muscle weakness,, and chronic fatigue; irritability, deppression, salt craving, and hypoglycemia may occur; half the time nasuea, vomiting, and diarrhea occur.
5. Cushing's disease: condition where the body produces too much cortisol resulting in obesity of upper body, increase in neck fat, rounded face, and thinning of legs and arms; skin become s thin and fagile, easily bruises, and slowly heals.
6. Amygdala [uh-MIG-duh-la]: part of the brain associated with the feelings of anger and of fear.
7. Hypothalamus [hi-po-THAL-uh-muss]: part of the brain that directs several maintenance activities, helps govern the endocrine system via the pituitary gland, and is linked to emotion.
Cortisol: steroid hormone in the body that makes sure there is enough glucose in the bloodstream, and it is primarily regulated via negative feedback by the hippocampus and is released out the outer layer of the adrenal gland (adrenal cortex)
A certain amount is needed for daily functioning, and too little (Addison's disease) and too much (Cushing's disease) result in undesired effects. Cortisol is released on a diurnal rhythm that peaks about an hour before waking and bottoms out around evening time.
Epinephrine: hormone more commonly known as "adrenaline" because it is released by the adrenal medulla (core of the adrenal gland)
Epinephrine courses through the bloodstream, causing an increased heart rate and blood pressure, constriction of veins in the extremities, increased lipid breakdown, and converting glycogen to glucose.
Norepinephrine: the neurotransmitter version of epinephrine and is released by the cells of the nervous system (neurons).
It causes an increase in heart rate and blood pressure and the veins in the extremities to constrict.
The Nervous System
When a stressor occurs, the amygdala is the first to know. It then activates the hypothalamus, which then activates the nervous system that releases norepinephrine to the body and activates the adrenal gland to release epinephrine into the bloodstream.
The HPA (hypothalamic-pituitary-adrenal) Axis
In this response, when the hypothalamus is signaled by the amygdala, the hypothalamus, in addition activating the nervous system, it activates the pituitary gland--king of the endocrine system--that sends through the blood ACTH (adrenocorticotropic hormone) that's sole purpose is to tell the adrenal gland to release cortisol.