Lecture #3 (2/7) Flashcards
What is the changes that occur during and in the hours after a single session of PA?
Acute exercise
What is the training that occurs over time due to changes in the structure/function of various systems
Chronic exercise
What is the ability of the cardio-respiratory system to deliver O2 to the exercise muscles called?
Central mechanism
What causes central mechanism in exercise?
Heart
Lung
circulatory
What is the delivery and extraction of O2 at the exercising muscles?
Peripheral mechanisms
What causes peripheral mechanism?
capillaries
mitochondria
enzymes
What is the combining/connecting central and peripheral processes?
systemic
What is the volume of blood pumped by the heart per minute?
Q-Cardiac Output
How do you calculate Q- cardiac output?
HR x SR
heart rate times stroke volume
What is the amount of blood in a ventricle at end diastole?
EDV- End diastolic volume
What is the amount of blood remaining in a ventricle at end systole?
ESV- End systolic volume
What is the volume of blood pumped by a ventricle (primarily the left) per beat?
SV- stroke volume
How do you calculate SV?
SV= EDV-ESV
What is the percent of ED that is pumped by the ventricle called?
EF- ejection fraction
What should the EF fraction be?
EF fraction should be about 55-60% or higher
What is the total volume of gas in liters exhale from the lungs per minute?
VE- minute ventilation
What is the air volume moved either during inspiration or expiration of each breathing cycle?
TV- tidal volume
What is the rate of breathing over one minute?
RR- respiratory rate
What is the volume of air which is inhaled that does not take part in the gas exchange, either bc of: Anatomic dead space or physiologic dead space?
VD- ventilatory dead space
What is anatomic dead space?
remains in the conducting airways
What is physiologic dead space?
reaches alveoli that are not perfused or poorly prefused
What is the maximal capacity of the lungs to move air over minute?
MVV- maximal voluntary ventilation
What are the three types of exercise?
aerobic
anaerobic
flexibility
What is the Pros of all three types of exercise?
aerobic- cardiovascular and burning calories
anaerobic- Strength and metabolism
flexibility- ROM and soreness
What are the basic responses of the body to PA?
1- going from rest to motion, cells are jolted out of resting state of balance
2- set of processes that supply the cell with extra energy
3- cells need additional oxygen to fuel the metabolic functions
4- to meet this demand, the respiratory and circulatory systems gear up to deliver O2 rich blood to working muscles
5- This accelerated metabolism, in turn, produces greater amounts of waste products
6-These products are transported back to waste-removal sites(kidney, lungs)
7- Therefore, HR and respiratory increases
8- other byproducts: heat, sweat, etc
How does HR increase in central acute response to exercise?
linearly to work
How is blood flow response to central acute response exercise?
Blood flow to the working musculature increases in proportion to the intensity of exercise
When is Maximum SV is achieved ?
at 50% of VO2 max
When does Q levels increase?
- resting level: 5L/min
- In sedentary people
- world class athletes
What are some common acute responses during exercise?
- increase in VO2
- decrease in systemic vascular resistance
- increase in systolic BP
- no change in diastolic BP
- Rate of breathing increases
What is the old HR formula?
220-age
What is the new HR formula?
208- (0.7xage)
What allows for increased total blood flow to the body during exercise?
acute changes in Q and BP during exercise
When does blood flow patterns change?
in transition from rest to exercise
How does blood get redirected to active areas during exercise?
Through SNS
What is it when with prolonged aerobic exercise or aerobic exercise in the heat, at constant exercise intensity.
Cardiovascular drift
What results of cardiovascular drift?
- decrease in arterial bp
- HR increases, allows maintenance of Q
What is the progressive increase in the amount of Q directed to the vasodilated skin to facilitate heat loss and attenuate the increase of body core temperature?
Cardiovascular drift
What occurs commonly during cardiovascular drift?
- more blood to skin for purpose of cooling the body
- less blood available to return to heart-decreases preload
With onset of exercise how much plasma is lost from blood to interstitial fluid space?
10% or less
Loss of plasma levels in blood can lead to what?
dehydration
increase blood viscosity
impair performance
What can result from reduction in plasma volume called?
hemoconcentration
What is a major determinant of carido-respiratory endurance capacity at near-maximal and maximal exercise intensities?
stroke volume
How is Stroke volume determined?
- volume of venous blood returned to the heart
- ventricular distensibility
- ventricular contractility
- aortic or pulmonary artery pressure
How much can stroke volume increase with increasing rates of work?
up to intensity between 40-60% of maximal capacity
Can stroke volume continue to increase up through max exercise intensities?
yes
What does stroke volume magnitude of changes in SV depend on?
position of body before and during exercise
During exercise the muscle pump functions to do what?
return blood to the heart or increase venous return
What is the extent to which ventricle fills with blood and stretches and subsequently contracts more forcefully call Frank starling mechanism known to do?
increase venous return
Preload
What is it when neural stimulation occurs without end-diastolic volume increases?
Increased ventricular contractility
What is it when vasodilation of blood vessels in exercising skeletral muscle?
decreased total peripheral resistance
What is the integration of skeletal muscle metabolism and the cardiopulmonary unit to determine what?
VO2- Oxygen consumption
VO2 is product of what two values?
cardiac output-Q
and
avO2 difference
What is avO2 difference?
the amount of O2 used by the muscle
Q is the product of what two values?
heart rate and stroke volume
What is the formula for VO2?
HR x SV x avO2 difference
What is the maximum volume of oxygen consumed by the body each minute during exercise. Because oxygen consumption is linearly related to energy expenditure, when we measure oxygen consumption, we are indirectly measuring an individual’s maximal capacity to do work aerobically.
VO2 Max
VO2 is also known as what?
Maximal Aerobic Power, Maximal oxygen consumption, maximal oxygen uptake, and maximal cardiorespiratory fitness
When is the greatest amount of O2 used?
during physical exercise
How is VO2 expressed?
L/min or ml/kg/min
What is VO2max an index of?
maximal cardiovascular and pulmonary funciton
VO2max is a single most useful measurement to what?
useful measurement to characterize the functional capacity of the oxygen transport system
VO2max is a limiting factor in what type of exercise?
endurance performance
What is the extent to which oxygen is extracted from the blood as it passes through the working musculature called?
Arterial-Venous oxygen difference
How is arterial-venous oxygen difference calculated?
difference between the oxygen content of arterial blood and venous blood
How does Arterial-venous oxygen difference increase?
increases with increasing exercise intensity, with more oxygen being extracted from the blood
When does Systolic pressure increase?
during dynamic exercise
How id Diastolic and Mean arterial pressure affected by dynamic exercise?
not changed significantly
How does resistance exercise affect BP?
can exaggerate BP
even as high as 480/350 bpm
Some BP increase during resistance exercise is due to what maneuver?
Valsalva maneuver
What is an acute effect after exercise of BP?
BP decreases for 3 hours post-exercise
What is an acute effect after exercise of TG?
Triglyceride levels decrease the morning after an exercise
What is an acute effect after exercise of RMR?
Resting metabolic rate increases for several hours following cessation of high-intensity exercise
What is a response cardiovascularly to regular exercise called and do?
“Training Response”
this results in an increase in maximum exercise tolerance, and a reduction in HR at a given exercise level
What are some major responses to training aerobically?
- increased Blood volume
- increased myoglobin content
- increased number and size of mitochondria
- increased capillary density
- increase in amount of oxidative enzymes
- increased oxidation of fat through increased intramuscular triglycerides
- increased release of FFA
- increased enzyme activity
What are some major response to training anaerobically?
- increased muscular stores of ATP and CP
- Increased enzyme activity
- increased muscular stores of glycogen
- hypertrophy of fast twitch fibers
The heart has a dense network of capillaries, how many capillaries per cubic millimeters?
about 2000 capillaries per cubic millimeter
Individual heart cells are densely packed with what cell organelle?
mitochondria
what percent of human heart cell volume consists of mitochondria?
25-30%
The heart can metabolize what three substrates with equal effectiveness?
fat
lactate
and blood glucose
What is the average person’s stroke volume and resting heart rate?
70ml/beat
70 beats/minute
What is the average yield of resting cardiac output?
5 L/minute
After 6 months of endurance training the resting HR can decrease to what bpm?
55bpm
Athlete’s heart have what sort size stroke volume?
larger stroke volume
At the beginning of exercise due to signals from joints, muscles of proprioceptors HR will what?
increase HR
End diastolic volume increases or decreases in the trained heart?
Increases EDV
EDV is affected by what?
- venous return= volume of blood returning to heart
- Preload= amount ventricles are stretched by blood
What is ESV affected by?
- contractility= myocardial contractile force due to factors other than EDV
- Afterload= back pressure exerted by blood in the large arteries leaving the heart
What is the preload or degree of stretch, of cardiac muscle cells before they contract and its a critical factor controlling stroke volume called?
Frank starling law
What leads to an increase of stretch of myocardial muscle?
increase in EDV, diastolic volume
What is the basic change reaction of Frank Starling law?
increase preload
increases stretch of cardiac muscle
increases force of contraction
increased SV
If SV is increased what happens to ESV?
ESV decreases with increased SV
What happens to SV with slow heartbeat or exercise increased venous return (VR) to the heart?
SV will increase
What are three ways VR-venous return changes?
1- blood volume
2- skeletal muscle activity
3- alterations in cardiac output
If Venous return increases what happens to EDV?
increases
What are some extreme situations that may lead to decrease in SV?
blood loss and extremely rapid heartbeat