Chapter 7 Flashcards
blood pressure
The force exerted by circulating blood on the walls of the body’s arteries / major blood vessel
diastole
pressure in the arteries/vessels when the heart relaxes
systolic
pressure in arteries/vessels when the heart contracts
primary hypertension
- no underlying conditions or diagnoses for cause
- gradual onset (10-20 yrs)
- increased BMI, stress, alcohol intake, physical inactivity
secondary hypertension
- results from underlying health conditions or certain medications
- thyroid disease, renal or kidney disease
- treat the underlying condition
temporal sequence
YES, risk factor was measured before outcome
- prospective cohort studies
strength of association
YES, the associations were considered significant and RR?OR’s are different than 1.0
consistency of results
YES, both observational studies and randomized controlled trials reported similar outcomes, reinforcing the reliability of the association between physical activity and lowered blood pressure
dose response
NO< a clear relationship remains inconclusive even though there is an inverse relationship
- studies focused on moderate levels of physical activity + inconsistent research on FITT principles
biological plausibility
YES,
- improved arterial & vascular function
- reduced systemic inflammation
- reduced sympathetic nervous system activity
( Poiseuille’s Law)
Which criteria can we say there is sufficient evidence for?
temporal sequence, strength of association, consistency of results, biological plausibility
blood pressure categories
normal: SBP < 120 & DBP < 80
elevated: SBP = 120-129 & DBP < 80
Hypertension (1): SBP = 130-139 & DBP = 80-89
Hypertension (2): SBP >= 140 & DBP >= 90
Hypertensive Urgency: SBP > 180 &/or DBP > 120
Poiseuille’s Law
basic determinants of blood flow/blood pressure
Q= deltaPpir^4/8nl
deltaP= pressure difference along a bv
pir= radius of a blood vessel
n= blood viscosity
l= blood vessel length
hypertension
SBP > 130 & DBP >80
high bp
pressure that we know starts to become damaging to our arterial walls
- develops from an abnormal elevation in one or all of the factors that influence blood flow or resistance to flwo
global burden
if everyone in a given
population reduced their blood pressure
below hypertension levels, 41% of
deaths due to hypertension would be
prevented.
Harvard alumni health study
- 2/3 of men engaged <
2000 kcal/week of leisure
time physical activity - After adjusting for age, a
30% greater risk of developing hypertension appeared likely for inactive individuals
-Those not participating in vigorous activity had 35% greater risk of hypertension - Moderately vigorous
sport participation also
reduced the risk of
hypertension
aerobic center
- Low physical fitness had a 50% greater risk of developing
hypertension. - Reduced fitness (going from high to low) resulted in an additional 28% increase in the risk of developing hypertension.
- Those with/ low fitness and elevated BP had 10 times the risk of developing hypertension compared to those with high fitness and normal BP
Why is the radius of a blood vessel considered a critical factor in regulating blood pressure according to Poiseuille’s Law?
Small changes in the radius lead to large changes in total
peripheral resistance
reduced tpr
our blood vessels become more compliant due to
improved endothelium (i.e., they can stretch and relax
much easier and are not as stiff»_space; less plaque)
effects of pa/exercise on blood pressure
- Reduced resting heart rate
* Increased parasympathetic activity and reduced sympathetic activity - Increased stroke volume
* This is good – it means more blood is able to return to the heart when it relaxes and
leave the heart when it contracts - Cardiac output remains the same – but the process influencing cardiac
output becomes more efficient
randomized control trials
SBP decreased by 5% in people with hypertension and about 2% in people who were prehypertensive or normotensive.
* Reductions of 3.3 mmHg (2%) SBP and 3.5 mmHg (4%) DBP were also observed after exercise training
