LEC13: Cardiovascular System (Age-Related Changes in Physiology and the Effects of Exercise)

Question 1

What are the three components to the cardiovascular system?

Answer 1

1. Heart
2. Blood vessels
3. Blood

Question 2

What does the heart do in the cardiovascular system?

Answer 2

Serves as a pump

Question 3

What do the blood vessels do in the cardiovascular system?

Answer 3

Passageways for blood to travel to all parts of the body and back to the heart

Question 4

What does the blood do in the cardiovascular system?

Answer 4

Act as a transport medium

Question 5

What is the main goal of the cardiovascular system?

Answer 5

To transport materials throughout the body

Question 6

What would be categorized as normal in terms of hypertension

Answer 6

Mean SBP/DBP < 120/80 mmHg

SBP: systolic blood pressure
DBP: diastolic blood pressure

Question 7

What would be categorized as elevated (previously pre-hypertension) in terms of hypertension

Answer 7

Mean SBP 120-129 mmHg and DBP < 80 mmHg

SBP: systolic blood pressure
DBP: diastolic blood pressure

Question 8

What would be categorized as stage 1 (previously pre-hypertension) hypertension

Answer 8

Mean SBP 130-139 mmHg OR mean DBP 80-89 mmHg

Question 9

What would be categorized as stage 2 (previously hypertension) hypertension

Answer 9

Mean SBP ≥ 140 mmHg OR mean DBP ≥ 90 mmHg OR

Self-reported use of medication for high blood pressure within the past month OR self-reported having been diagnosed with hypertension by a health-care professional

Question 10

Individuals with SBP and DBP in 2 categories, the category should be designated to the (blank)

Answer 10

Higher BP categories

Question 11

What are some (3) structural changes in the cardiovascular system with age?

Answer 11

Thickening of the walls of the large arteries
- With age, the internal layer (tunica intima) of the artery thickens and fragments - a process similar to what happens with early-stage atherosclerosis

Increased stiffness of the large arteries, small arteries, and arterioles (less compliant)
- With age, the regulation of vasodilation is impaired (vessels are less responsive to biochemical cues for dilation)

Thickening of the walls of the left ventricle

Question 12

What is heart rate?

Answer 12

The number of times the heart beats in one minute

Question 13

Is the average resting heart rate of older adults significantly different from young adults?

Answer 13

No. It is not significantly different

Question 14

What is the difference in heartrate between ages?

Answer 14

Maximum HR (associated with heavy exercise), decreases 5-10 beats per minute each decade

Question 15

What is the maximum heart rate calculation for individuals over 40 years

Answer 15

208 - (0.7 x age)

Question 16

What is stroke volume?

Answer 16

The amount of blood (in ml) pumped from the heart with each beat

Question 17

What are the changes in stroke volume with age?

Answer 17

Resting supine stroke volume showed little change with aging in men or women

With age, stroke volume changes, in response to increased activity, do not happen as efficiently due to several factors

Question 18

What is cardiac output?

Answer 18

The total amount of blood ejected from each ventricle of the heart in 1 minute, expressed in liters per minute (L/min)

Cardiac Output = Stroke volume x Heart Rate

Q = SV x HR

Question 19

What are the changes in cardiac output with age?

Answer 19

At rest, not a big difference

Older adults cannot modulate stroke volume at maximum exercise, and heart rate max is blunted. Yes, there is a change

Question 20

What is Arteriovenous Oxygen ((av)O2) Difference

Answer 20

The difference between the amount of oxygen transported in the arterial blood and the amount of oxygen transported in the mixed venous blood

Question 21

At rest, what is the (a-v)O2 difference

Answer 21

~5 ml O2/100 ml blood

Question 22

During maximal exercise, what is the (a-v)O2 difference?

Answer 22

~ 15 ml O2/100 ml blood

Question 23

What are the differences in arteriovenous oxygen ((av)O2) with age

Answer 23

With age, (a-v)O2 difference decreases
- E.g. 65 yr old male has an (a-v)O2 difference 20-40% lower than a 25 yr old male

Question 24

What is maximal aerobic capacity (VO2max)?

Answer 24

The maximal rate at which oxygen can be taken up,
distributed, and used by the body during exercise that
engages a large muscle mass (measured in ml * kg-1 * min-1)

VO2max = Cardiac Output X (a-v)O2 difference

Question 25

How does age change VO2max?

Answer 25

VO2max declines about 1% per year for each year after age 25

Question 26

What is the cardiopulmonary system?

Answer 26

The heart operates in partnership with the lungs to ensure the efficient transport of blood to and from the heart to facilitate the exchange of oxygen and carbon dioxide

Question 27

What are some (4) structural changes in the cardiopulmonary system with age?

Answer 27

Reduction in alveolar surface area = less surface area for gas exchange to occur

Loss of elastic recoil of the lungs = increase work required for respiration

Increased chest wall stiffness = increase work required for respiration

Decreased inspiratory muscle strength (e.g. diaphragm, intercostals) = increase work required for respiration

Question 28

Cardiopulmonary system structural changes: reduction in alveolar surface area

Answer 28

Less surface area for gas exchange to occur

Question 29

Cardiopulmonary system structural changes: loss of elastic recoil of the lungs

Answer 29

Increase work required for respiration

Question 30

Cardiopulmonary system structural changes: increased chest wall stiffness

Answer 30

Increase work required for respiration

Question 31

Cardiopulmonary system structural changes: decreased inspiratory muscle strength (e.g. diaphragm, intercostals)

Answer 31

Increase work required for respiration