Week 05 Flashcards
End-diastolic volume (EDV) is…
Volume of blood at the end of ventricular filling
Stroke volume is…
Amount of blood ejected from each ventricle during systole
End-systolic volume (ESV) is…
Amount of blood remaining after the end of contraction
Ejection fraction (EF) is…
% of EDV pumped from ventricles
Cardiac output (Q) is..
Volume of blood pumped by each ventricle per minute
Myocardium in older adults is slow to relax following contraction due to the:
- Slower calcium reuptake by sarcoplasmic reticulum
- Changes in myosin heavy chain composition of myocytes
- Prolonged action potential
Late diastolic filling is greater with age due to ______ blood volume contained in enlarged atria
increased
_____ decreases about 1% per year
cardiac output
_______ may decrease as much as 30% by age 85
stroke volume
Blood pressure is a product of ___ and ____
cardiac output and peripheral resistance
Within the arterial system, what exerts primary influence over vascular resistance?
small arterioles
Adequate delivery of blood depends on the ______ driving the blood and the state of the _______ in the arteries and arterioles in the organ
Pressure, resistance
List the layers of arteries/arterioles from inner to outer
- Tunica intima (endothelium)
- Tunica media (smooth muscle cells)
- Tunica adventitia (collagen fibres)
State of blood vessels tone refers to the balance between competing ____ and _____ influences
dilatory, constricting
Blood vessels tone refers to the balance between competing dilatory and constrictor influences such as (3)?
- Compounds produced by endothelial layer (e.g. nitric oxide)
- Sympathetic nerves release vasoconstrictor neurotransmitters
- Circulating hormones and catecholamines
Major conduit arteries, such as the aorta, get stiffer and longer with age, due to (2)?
- Thickening of structural materials that make up vessel wall
- Increase in sympathetic tone of smooth muscle
Arterial remodelling can be (3)?
- hypertrophic: thickening of vascular wall
- eutrophic: constant wall thickness
- hypotrophic: thinning of vascular wall
Greater ______ density in adventitia of older inactive group but not in older active group
collagen
Carotid artery stiffness greatest in older inactive group. _____ levels of arterial stiffness between young groups and older active group
similar
Vascular endothelial dysfunction is partly responsible for the ______ risk of cardiovascular disease with advancing age
increased
Reduced bioavailability of ______ is the key mechanism in endothelial dysfunction with age
nitric oxide
Correlational between reduced ______ function and heart disease
endothelial
Endothelial function and __________ are associated —> however can be reduced by lifestyle factors
increased age
Lifestyle factors that affect endothelial function?
- regular aerobic exercise
- dietary factors
- body weight / fat percentage
- vitamin D status
- menopause (oestrogen deficiency)
When young trained athletes and older trained athletes compared - there was/wasn’t a decrease in endothelial function with age (unlike sedentary older individuals)
wasn’t
Are older individuals able to improve their endothelial function?
Yes, almost reverse it with exercise
With age, sympathetic nerve activity decreases/increases?
Increases
High levels of sympathetic nerve activity result in increases in ?????? and ultimately hypertension
peripheral vascular resistance
Muscle sympathetic nerve activity (MSNA) increases with age, with greater effect in _____
females
Resting mean arterial pressure also increases with age (may be related to ___________), however pattern is different —> other factors must be involved
increase in muscle sympathetic nerve activity
Arterial stiffness causes/contributes to elevated ___________ velocity and ______ BP
pulse wave, systolic
Arterial stiffness causes/contributes to reduced ability to absorb …?
energy during systole
Elevated sympathetic nerve activity (SNA) causes/contributes to (3)?
- more vasoconstriction
- greater vascular resistance
- elevated BP
Exercise capacity falls with age: decrease in VO2 max of approx. ____ % per _____- from age of 25
10% per decade
Sedentary vs trained VO2 max as they age?
Both falls 10% every decade, however trained is higher to start so stays a little higher ass they age
Decline in Vo2 with age is attributed to…(3)?
- decreased cardiac output
- decreased a-vo2 difference
- loss of muscle mass
Factors influencing blood flow decrease at rest with age?
- Limb blood flow at rest reduced with age
- Associated with elevated MSNA (increasing vascular tone)
- Other contributors: fewer blood vessels available and/or inability to dilate blood vessels
- Due to ageing or physical inactivity associated with ageing???????
Improvements in Vo2max in elderly explained is mostly by _____ (since max HR stays the same following training)
stroke volume
Moderate intensity training in elderly: gains up to around ___% Vo2max
20%
Mean increase in VO2max after training in all studies was ___%
16.5%
The longer the durations, the better increase in ____
vo2 max
increases in VO2max around ___% even in individuals averaging 72 Yrs old with aerobic training
18-19%
Does physical activity improve sympathetic nerve activity?
Unknown
Regular physical activity has positive impacts on:
- endothelial function
- vascular compliance
- maximal and submaximal exercise performance
During maximal exercise improvements:
- increased ventilation
- increased O2 consumption
- increased CO
- increased a-vo2 diff
During submaximal exercise improvements:
- decrease ventilation
- decreased HR
- decreased SV
- decreased BP
Advancing age is associated with structural and functional changes to the heart, including ___ ____ hypertrophy and ____ myocardium relaxation
left ventricular, slower
Age related vascular changes include vascular stiffening, endothelial dysfunction and elevated nerve activity, which can be associated with elevated _______ and reductions in limb BF
blood pressure
Which cardiovascular factor declines with age in sedentary individuals?
Endothelial function
In growing children, how do changes in cardiac size, particularly left ventricular mass, relate to changes in lean body mass?
There is a positive correlation between left ventricular mass and lean body mass
LV end diastolic volume (LVEDV) does/ does not change with age
does not
Late diastolic volume is typically reduced in older adults (T/F)?
False
