exam 3 Flashcards
Stress definition
the physiological response to a physical, mental, or emotional challenge, or perceived challenge that activates the sympathetic nervous system and the HPA axis
Physical stress examples
exercise, malnutrition, injury/illness, dehydration, temperature
Psychological stress examples
Worrying, anxiety, fear, pressure to succeed
2 parts of the autonomic nervous system
parasympathetic and sympathetic
Parasympathetic actions
slows heart beat, stimulate digestion, constrict lungs, penile erection, vaginal lubrication
sympathetic actions
adrenalin rush, increase heart beat, inhibit digestion, dilate lungs, ejaculation, orgasm
Glucocorticoids are
stress hormones
Cortisol is
the most well known glucocorticoid
Steroid hormones
testosterone, estrogen, progesterone
What do glucocorticoids do?
Energy mobilization
ie. glycogen to glucose
Insulin
a hormone secreted by the pancreas that causes cells to absorb glucose
T1DM
congenital, autoimmune disease. Immune system kills cells in the pancreas that secrete insulin, insulin dependent
T2DM
late onset, insulin receptors on cells become resistant to insuling, associated with obesity. Insulin resistant
How does stress complicate diabetes?
- stress puts more glucose into the blood
- stress promotes insulin resistance
T1DM stress effect
difficult to balance blood sugar
T2DM stress effect
worsens syndrome
True or false: Stress shuts down digestion
True; because it requires lots of energy
Irritable Bowel Syndrome Symptoms
- stomach pain relieved by defectation
- diarrhea or constipation
How does stress increase the risk of getting IBS?
repeated turning on and off of the digestive system results in loss of coordination of the components of the system
Ulcer definition
a hole in the wall of an organ
Peptic ulcer definition
ucler of the stomach of the portion of the esophagus or intestine immediately bordering the stomach
bacteria that causes peptic ulcers
Helicobacter pylori
How does stress increase the risk of getting a peptic ulcer?
Weakening of the stomach walls and suppressed immune system
How does severe stress stunt growth?
- reduced release of GHRH from hypothalamus
- Increased release of GHIH
- Reduced sensitivity to growth hormone
- Fail to absorb nutrients
What is the critical variable in child neglect that leads to stunted growth?
active touching
Epigenetics
the study of heritable phenotypic changes that do not involve alterations in the DNA sequence.
LH works synergistically with FSH
releases testosterone and produces sperm in males. In females, it regulates periods, stimulates ovaries to release estrogen and produce and release eggs
How does stress affect the reproductive system?
less LHRH(GnRH). increased endorphins released into the hypothalamus shuts off LHRH cells
Sexual side effects of stress
too much sympathetic action, no erection, no lubrication, premature ejaculation
More effects of stress on sex
reduced libido, miscarriage
Macrophages and neutrophils
white blood cells that phagocytose dead or foreign material and release alarm signals
Lymphocyes
white blood cells that recognize, remember and respond to foreign invaders
Innate parts of immune system
inflammation, vasodilation, cytokines, neutrophils, macrophages
Acquired (adaptive) parts of immune system
antibodies, antigens, lymphocytes
B cells
lymphocytes that produce antibodies and release cytokines (chemical alarm signals)
Cytotoxic T cells
lymphocytes that kill infected or targeted cells
Helper T cells
lymphocytes that recognize and remember antigens and signal other cells to their presence
2 ways immune systems fail
- not repair the damage
- autoimmune diseases
How does stress affect the immune system?
acute stress enhances immunity while prolonged chronic stress shuts it down
Synthetic glucocorticoids are used to treat
- autoimmune diseases
- reduce inflammation
- after organ transplant
How does stress affect cancer?
- compromised immune system allows cancer to spread
- glucocorticoids provide energy for cancer cells
Short term memory
remembered for seconds, minutes, or hours then lost
not dependent on gene expression
Long term memory
remembered for days, weeks, years, a lifetime
dependent on gene expression
Memory trace
biochemical change in the brain which encodes an experience, which lasts beyond the stimulus
Consolidation
stabilization of the memory trace
Reconsolidation
stabilization of the memory after bringing it back into awareness
Retrieval
bringing the memory into awareness
Extinction
learning that a context is no longer associated with a stimulus
Forgetting
loss of the memory trace
Implicit, procedural memory
things like riding a bike, walking, or driving
Explicit, declarative memory
things like remembering who was the president, the smell of your grandmother’s cupcakes
Cerebellum and dorsal striatum are
coordinators of movements. critical for habit learning, procedural and skill learning
Hippocampus
- integrator of sensory information
- binds information about events, time and space
- critical for forming new declarative memories
Acute stress enhances memory due to
increased glucose in the blood and increased blood flow to the hippocampus
Chronic stress _____ cognitive performance
impairs
4 ways chronic stress impairs memory
- neuron damage, shrinking of neurons, weakening memories
- neuron vulnerability
- neuron death
- reduced hippocampal neurogenesis
Chronically elevated glucocorticoid signaling is associated with
a small hippocampus
Smaller hippocampus is associated with
- cushing’s disease
- ptsd
- major depression
- normal aging
- synthetic glucocorticoids
Cushing’s syndrome is
hypertrophy of the adrenal glands
Cushing’s syndrome is associate with
memory impairments
Chronic exposure to synthetic glucocorticoids is associated with
memory impairments
Why do high levels of glucocorticoids make neurons vulnerable?
chronically elevated glucocorticoids eventually cause neurons to starve for energy which causes reduced storage of energy in astrocytes and neurons
Older people have higher resting levels of glucocorticoids which causes
it to take them longer to decrease levels of glucocorticoids after stress
Displaced aggression
when you get treated poorly by your superior, you treat your subordinates poorly
Meditation
Opposite of stress. Parasympathetic activity is high, glucocorticoids low, breathing is slow, heart rate is slow
How can exercise help people cope with stress if it is a stressor itself?
- exercise is an acute stressor
- when you exercise you use stress response adaptively
- exercise causes other physical stressors to be less stressful
4.exercise increases hippocampal neurogenesis which makes psychological stress less stressful
How does exercise stress make psychological stress feel less stressful?
increasing the number of neurons in the hippocampus causes the sensor sensitivity in the negative loop to increase thus lowering glucocorticoids
Stress predictability effect
If we know when to expect a stressor, it is less stressful
Depression
failure to cope with stress, loss of control, helplessness, hopelessness, cup is always half empty
Chronic exposure to glucocorticoids increases
risk for depression
Cushing’s disease is associate with
increased depression
Depression is more common in
older people
Glucocorticoids kill hippocampal neurons and reduce adult hippocampal neurogenesis. This impairs the sensor in the negative feedback loop resulting in
Greater accumulation of glucocorticoids, which cause more damage to the hippocampus, resulting in negative spiral
