lecture 19 Flashcards
what are the 3 Neural Mechanisms for Responding to Short term stress
- Direct behavioral
- Via pons
- Freeze and flinch (startle reflex)
- No thinking required, all subconscious - Sympathetic system (global effects)
- Via the non hormone part of the hypothalamus - Hormonal (global effects)
- Via the hormone releasing part of the hypothalamus
what is the Sympathetic nervous system
- fight or flight system, energy system
- Originates in hypothalamus which receives from the amygdala
how does the sympathetic nervous system from the neural projections from the Hypothalamus to Adrenal Medulla (inner part of Adrenal Gland)?
releases hormones into blood: Adrenaline and Noradrenaline
what are the two effects of adrenaline/noradrenaline
- Increases heart rate, blood pressure, breathing rate
- Stimulates liver to breakdown glycogen → glucose
(glucose is originally stored as glycogen)
what is the Hypothalamus-Pituitary-Adrenal Cortex Axis? (3. Hormonal)
Hypothalamus releases a hormone into the pituitary and it insights to release adrenocorticotropic hormone (ACTH) into blood which activates the adrenaline cortex which insights it to release cortisol into the blood
what are the 3 effects of cortisol?
- Stimulates liver to breakdown glycogen → glucose
(like Adrenaline and Noradrenaline) - Increases heart rate, blood pressure
(like Adrenaline and Noradrenaline AND direct neural input from hypothalamus to heart and lungs) - Increases metabolic rate: glucose + oxygen → energy (ATP)
Together, Sympathetic system (2) and Hormonal (3) increase:
1) Amount of “fuel” in blood, i.e., glucose (through glycogen breakdown)
and oxygen
2) Heart rate and blood pressure (which speeds up how quickly fuel gets to brain and muscles)
3) Metabolic rate (which makes energy (ATP) more quickly)
is short term stress (from Fear/Anger) adaptive?
is long term stress (Anxiety) adaptive?
- Yes, Needed for high levels of activity associated with “fight or flight
- No
what is The Placebo Effect
Real improvement in symptoms brought on by a belief in treatment
what is Psychosomatic Illness
Real illness brought on by a negative psychological state
(short-term stress, anxiety, anger, depression)
what are the 2 examples of short(er)-lasting illnesses (psychosomatic illness)
- indigestion: bloating, cramps, gas (if sympathetic system is on it stops digestion, if parasympathetic is on then it increases digestion bc it is homeostatic)
- Stress migraine
- Sympathetic system (stress) vasoconstricts (makes smaller and harder) blood vessels → ischemia (blood is not getting to certain part of brain) → auras
- Parasympathetic system rebounds - vasodilates blood vessels (stretches it too much) → stretches pain receptors → pain
what are the 3 examples of longer lasting illnesses (psychosomatic illness)
- High Blood Pressure
(can lead to Cardiovascular Disease) - Memory loss
- Stomach ulcers: open/bleeding sores in the stomach/intestines from gastric enzymes
- Immune deficiencies
what are the 2 ideas about stomach ulcers
- Rebound of the parasympathetic input after sympathetic is turned on strongly
- people with ulcers have Helicobacter pylori bacteria, but so do people who dont have uclers sooo…
bacteria is necessary, not sufficient
its the combination of the bacteria + stress
How could stress dampen the immune system?
When energy in the body is used for stress conditions (nothing serious…like taking an exam), there is less energy left over for homeostatic functions, like protein synthesis, to create immune cells
Neural projections from the Hypothalamus to Adrenal Medulla (inner part of Adrenal Gland) release what?
releases hormones into blood: Adrenaline and Noradrenaline
