Lab Quiz 2 - 2 Flashcards
Name of professor who studies stress in baboons?
Robert Sapolsky
Which hormones are central to stress response?
Adrenaline
Glucocorticoids
Link between hormone stress levels and hierarchy:
Dominant males have lower levels of glucocorticoids and adrenaline
Submissive animals have higher levels of glucocorticoids and adrenaline
Link between stress hormone, hierarchy and physiological state:
Low rankers -> higher stress hormone levels -> high blood pressure, increased heart rates, weaker immune systems, reproductive system is more vulnerable, brain chemistry similar to clinically depressed humans
Who tracked the health of humans according to hierarchy?
- Study name?
Sir Micheal Marmmot Whitehall study (all jobs are ranked here)
Whitehall study found:
People lower in the hierarchy have high blood pressure, increased heart rates, weaker immune systems. (likely higher stress levels)
Hierarchy matches what is seen in humans
Whitehall study and weight correlation:
Lower ranked individuals are more likely to be obese
Stress and ulcers?
- Causes of ulcers:
Ulcers caused by a bacterium
Bacterium is present in all individuals
Stress disrupts immune system
Bacterium can then cause damage aka ulcers
Who studies macaques?
Carol Shivley
Macaques and arterial condition and hierarchy:
low on the hierarchy -> increased stress hormone levels -> increased blood pressure/heart rate -> increased probability of atherosclerosis/arteriosclerosis
Effect of chronic stress on brain cell branching in rats?
It decreased branching neurons (in hippocampus)
Which region shrinks in response to chronic stress?
Hippocampus (memory and learning)
Two effects of stress on memory:
- Chronic: can change brain circuits, reducing ability to remember
- Sever Acute Stress: making it so you can’t remember things in the short term you know perfectly well (when you blank on an exam)
Hierarchy effect on dopamine levels and pleasure:
Less dominant monkeys have less dopamine
Less dopamine = less pleasure from life
In addition to stress increasing weight gain, what region does stress increase weight gain in?
The center of the body (abdomen)
Why is fat produced by stress more dangerous?
It is on the trunk/inside the abdomen produces different hormones and chemicals and has more dangerous effects on your health
Findings of the dutch hunger winter (response to famine is similar to other stressors):
Stress in fetal life:
- Increased risk of cardiovascular disease:
- More risk of hypercholesterolemia:
Chronic stress effect on telomere length:
If an individual is more highly stressed, their telomeres shorten faster.
Degree of stress, and duration of stressor both correlate with shorter than average telomeres for age
What repairs telomeres?
- What activates this system?
Telomerase
- What activates this system?
Higher levels of interconnectivity and compassion
What happened to the keekorok troop (the first baboons he had ever studied):
Foraged for food in trash -> exposed to tuberculosis -> almost half the males in troop died
Who died and who survived the tuberculosis in the keekorok troop?
Aggressive, and not socially connected (didn’t groom) died.
All alpha males died.
Only the “good guys” survived
Transformed atmosphere of the troop.
Chronic change keekorok troop:
Animals become polite, new members who joined the troop eventually became nice.
- Lower blood pressure, lower stress, less brain chemistry related to anxiety
Keys to stress reduction:
Control, involvement, and reward
- People must choose to focus on whatever hierarchy they have control over
Find a place we have control:
- Give people more control, involvement, reward and they will likely work harder and be healthier
EKG/ECG stands for?
Electrocardiogram
What are the two types of control exerted on the heart?
Autonomic system: speed or slow the heart Intrinsic conduction (nodal) system: SA -> AV (.1 sec delay) -> bundle of his -> left/right bundle branch -> purkinje fibers
Which ventricle has a more complex network of purkinje fibers?
Why?
Left
Larger
Alternative name for the bundle of HIS?
Atrioventricular Bundle
An electrocardiograph produces a?
Electrocardiogram
backwards
ECG waves:
- P: Atrial depolarizes
- QRS: Ventricles depolarize, atria repolarize
- T: Ventricles repolarize
Flaws of the ECG:
Record of voltage over time
- Muscle does not have to follow voltage
- Detects depolarization and repolarization of myocardium, the nodes themselves cannot be detected
P - R (P - Q):
- Define:
- Duration:
- Corresponds with:
- Define:
Represents the time between atrial depolarization and ventricular polarization (time it takes to travel through AV node and AV bundle, left/right bundle branch, purkinje fibers to depolarize tissue - Duration:
.16 - .18 seconds - Corresponds with:
Time spent in conduction
Period during which atrial systole occurs
A prolonged P - Q (P - S) likely means:
partial atrioventricular node block due to damage (slower conduction)
Total AV block would look like?
AV node does not transmit.
The atria and ventricles beat independent of each other (atria is faster, due to the SA node)
QRS interval:
- Define:
- Duration:
- Extended duration meaning?
- Define:
Time it takes the ventricles to depolarize - Duration:
.04 - .12 seconds - Extended duration meaning?
likely left or right bundle branch block, one ventricle must depolarize, then spread to the adjacent ventricle, this is slower, causing the prolonged depolarization
Q - T interval:
- Define:
- Duration:
- Define:
Time from ventricular depolarization to repolarization. Corresponds to ventricular contraction - Duration:
.3 - .44
Heart rate changes the duration of which interval?
The Q - T interval (timeframe over which the ventricle is contracted)
> 100 beats / minute =
Tachycardia
< 60 beats / minute =
Bradycardia
Why does bradycardia exist in athletes?
They have increased stroke volume, so their heart can beat more slowly
Einthoven’s triangle:
Bipolar leads at left ankle, and both wrists
What triangle is used by bipolar leads?
Einthoven’s triangle
Leads of a typical ECG machine:
- leads of ours:
12 leads (3 bipolar, einthoven's triangle, 9 unipolar) 10 leads, but we used four
Bipolar leads measure:
The difference in voltage between limbs (RA, LA, LL)
Lead 1:
RA - LA
- has one L
Lead 2:
RA - LL
- has two L’s
Lead 3:
LA - LL
- has three L’s
How is the middle lead, lead II calculated?
L2 = L1 + L3
- L2 is not recorded, but calculated
What cream did we apply to the conduction site?
Why?
Keratin cream
Better conduction/voltage detection
How many seconds does the machine travel in a mm?
.04 seconds / mm
QRS -> QRS takes 20 mm, what is the heart rate?
.04 (sec/mm) * 20 (mm) = .8 seconds / beat
60 / .8 (seconds / beat) = 75 beats/second
breath holding causes what effect?
Slowing of the heart rate (temporary bradycardia)
