Aging and functional Assessment: Exam 1 Material

Test. How is it classified?

An instrument or tool used to make a measurement

The test is classified based on what it is measuring

For instance, a cognitive test assesses intelligence

Measurment

The act of collecting data from a test in order to quantify an effect, variable, or any desired aspect.

Evaluation. What crucial piece of information do you need to evaluate

Interpretation of data obtained from measurements.

To evaluate something you will need a reference standard:

Norm referenced standard: Compare the results to a well defined comparison group. For instance you may measure a percentile of a variable; 70th percentile score within a group (so above average, but within 1 SD)

Criterion referenced standard: Predetermined threshold that classifies whether or not their is an achievement (could be categorical).

Correlation

A measure that indicates the size and direction of a relationship between two variables

.r What is it and what assumptions does it make

pearson coorelation coefficient. Indicator of the linear relationship between two variables.

It assumes both variables are normally distributed.

Magnitude: from -1 to +1

Direction: +, -, 0

What is the top cause of mortality for adults over the age of 65? What can be doing to prevent this

Deterioration of the respritory or cardiovascular system. Systemic exercise can enhance these systems and prevent this deterioration.

Age related declines in respritory and cardiovascular system is accelerated by what? Is this observed during rest or exercise?

Sedentary behavior, physiological changes are observed during exercise

Cardiovascular system

Transports all substances important for cellular metabolism such as o2 into cell and co2 out of the cells

Clots to prevent blood loss

Age relates structural changes related to the cardiovascular system,

• Aorta and arterial walls

  • Thicken and stiffen. In other words they are less compliant

    • This leads to an increased systolic BP

• Left ventricle

  • Increases in thickness by 30%

    • Compensates for increased systolic BP so there is more contractile force to overcome the increased pressure

• Atherosclerosis

  • Structurally changes the structure and function of the CV system in a deleterious way.

    • The new structure puts more stress on the total CV system

Maximal heart rate changes with aging?

Contributing factors?

Maximal heart rate decrease

Force of contraction decreases

Hormonal changes are resposible:

• Higher norepinephrine levels during exercise in elderly

• Higher epinephrine levels during rest and exercise in elderly

There is a reduction in sensitivity of the heart to hormones that signal harder contraction and higher HR with age.

SV

Amount of blood pumped out w/ each beat

Cardiac output (Q) total blood ejected from the ventricles in 1’

Changes in HR, SV, and Q during aging

Heart rate

• RHR is unaffected by aging

• MHR declines by 5-10 BPM per decade

SV

• Little change with aging

Q

• Reduces with aging Especially during maximal exercises

A-Vo2 difference

Amount of oxygen consumed/ extracted from the tissues

AVO2 dIFFERENCES with age

Reasons for change

At rest:

• Reduced by 20-30%

With exercise

• Reduced by 10-12%

Reduced capillary density

Reduced mitochondrial density

More blood diverted to skin and viscera instead of working muscle

Reduced vasodilation in response to corresponding signals

Systolic BP

Pressure generated by heart against the arterial walls during ventricular contraction. Related to Q

Diastolic BP

Arterial pressure without pressure from contraction. Associated with peripheral resistance and continuous BF into arteries and capillaries

Systolic and Diastolic BP changes with age? Why?

Systolic increased

Diastolic Increases

Higher rigidity of arterial walls resists TPR

Arteries exert greater resistance to PBF increasing systolic to maintain Q

Seniors have a 60% rate of hypertension in men and 70% in women

vo2 max

•Maximal O2 delivery and utilization with exercise

•Single best variable to define overall physiological change that occur with aging

Vo2 max change w/ age

decreases irrespective of training; more pronounced in sedentary folk

Declines accelerate from 75-85 from 65-75

HoW to increase vo2

Properly prescribed exercise

Elderly may not achieve same absolute gains as young folk but may achieve same relative gains

Why does vo2 increase w/ training

Q increases w/ exercise because of SV increases (remember MHR cannot be changed)

AVO2 difference increases

§↑ capillary density

§↑ mitochondrial density

§↑ amount of blood sent to muscle, ↓ blood diverted to viscera and skin

§↑ vasodilation response

Why does exercise reduce Hypertension? What kind of exercise

Low dose frequent exercise reduces BP

Mechanisms for decrease:

Lower RHR

Lower resting Q

Lower TPR

Lower norepinephrine levels

Lower sympathetic innervation

Improved renal function

Lower BW and body fat

Things you cannot change

Genetics

Being man

Being old

Things you can change to prevent Heart disease

High BP

Smoking

High cholesterol

Physical inactivity

Obesity

Diabetes

Deterioration of cardiovascular system can lead to heart diseases

Population based risks for heart disease

Respritory changes w/ aging

15% decrease in alveolar SA

• Fewer alveoli per unit of volume

• More physiological dead space

• Less SA for gas exchange

Increase in large airway diameter

Decrease in small airway diameter

Increased work required for breathing

• Loss of lung elastic recoil

• Increased chest wall stiffness

Gas exchange and ventilators pump

•Gas Exchange (O2 and CO2) occurs between alveoli of lungs and blood

•With aging, gas exchange is affected

•Arterial oxygenation impeded

•CO2 elimination unaffected

•

•Ventilatory pump

•Consists of chest wall, respiratory muscles, and respiratory centers

•All are affected by aging

•Chest wall stiffness increases

•Respiratory muscle strength decreases

•Decreased respiratory center sensitivity to hypoxia

Respriatory effects of exercise

•Respiratory Function

•Exercise postpones losses in respiratory function

•Endurance training improves respiratory function

•

•VO2max

•Most changes improving performance are related to cardiac output and a-v O2 difference, not respiratory improvements

Effects endure only with continual exercise