Exam 2 Flashcards
With most energy not able to be seen, how can we detect it?
Heat is our means of detection
Substrate Metabolism Efficiency for ATP and Heat
40% of Substrate Energy –> ATP 60% of Substrate Energy -> Heat
What is Direct Room Calorimetry?
Measuring all mechanics related to energy production such as Heat and Gases
What is Indirect Calorimetry?
Estimates total body energy expenditure based on O2 used, and CO2 produced.
What does Indirect Calorimetry measure?
Measures respiratory gas concentrations
Indirect Calorimetry only accurate for?
Oxidative Metabolism. Only good for up to VO2max and below!
What is VO2?
Volume of O2 consumed per minute. OR Rate of O2 Consumption
VO2: O2 usage during metabolism depends on
type of fuel being oxidized.
VO2: What happens if more carbon atoms are in molecule?
More O2 is needed.
VO2: Equation
Glucose (C6H12O6) < Palmitic Acid (C16H32O2)
What is VCO2?
Volume of CO2 produced per minute. OR Rate of CO2 production
What does RER stand for??
Respiratory Exchange Ratio
What is the Respiratory Exchange Ratio?
Ratio between rates of CO2 production and O2 use.
Formula for RER?
VCO2 / VO2
RER for 1 Molecule Glucose?
1.0
What is primarily consumed with a RER of 1.0?
Carbohydrates
RER for 1 Molecule Palmitic Acid?
0.70
What is primarily consumed with a RER of 0.7?
Fats
Formula for 1 Glucose Molecule?
6 O2 + C6H12O6 –> 6 CO2 + 6 H2O + 32 ATP
RER for Glucose?
6 CO2 / 6 O2 = 1.0
Formula for 1 Molecule Palmitic Acid?
23 O2 + C16H32O2 -> 16 CO2 + 16 H2O + 106 ATP
RER for Palmitic Acid?
16 CO2 / 23 O2 = 0.7
Assumptions for Gas Measurement of O2?
Storage of O2 is constant
Assumptions for Gas Measurement of CO2?
CO2 breathed off is equal to CO2 production at cells
Assumptions for Gas Measurements of CO2 Produced Via
Energy Pathways H+ being added to bicarbonate system
VO2 can lead to ..
Max or Peak Submax
Measures related to Training Prescription, Performance, and Fatigue
VO2 Lactate Threshold Critical Power / Speed
Slow Component of O2 Uptake Kinetics
At high power outputs, VO2 continues to increase. More Type II (less efficient) fiber recruitment.
What is the Critical Power / Speed?
Threshold between sustainable intensities and unsustainable intensities. Calculated asymptote of the power / speed curve.
What can Critical Power be used for?
To determine sustained race pace for a given distance or time. Other calculations can tell you how much energy you spend above CP. (Can go at 98-99% of CP for duration of race.)
What happens if you train?
Use O2 better, normal internal changes, and in 8 weeks, you can add 50 W to CP
Definition of Fatigue for Inability?
Inability to maintain required power output to continue muscular work at given intensity
Definition of Fatigue for Decrements?
Decrements in muscular performance with continued effort, accompanied by sensations of tiredness.
Is Fatigue reversible?
Yes, at rest.
Fatigue causes?
Complex Phenomenon Major Causes Phosphocreatine
Fatigue - Complex Phenomenon
Type, Intensity of Exercise Muscle Fiber Type Training Status, Diet
Fatigue - Major Causes (1-2)
Accumulation of metabolic by-products Failure of muscle contractile mechanism
Fatigue - Major Causes (3-4)
Inadequate energy delivery/metabolism Altered neural control of muscle contraction (Ionic valances can go whack after intense exercises)
Definition of Exhaustion?
Action or state of using something up or something being used up.
Fatigue - Phophocreatine
PCr depletion coincides with fatigue. PCr used for short term, high-intensity effort. PCr depletes more quickly than total ATP
What helps eliminate PCr Depletion?
Pacing helps eliminate PCr depletion
Fatigue - Phophocreatine by products?
The by products are Phosphate and Hydrogen, and they will be fatigued quicker.
Increased resistance in the arterial system would decrease cardiac output. Which of the following mechanisms related to cardiac output deals with the resistance of the arterial system?
increase in afterload
Following aerobic training, How would a person’s heart rate change at a given workload versus what their heart rate was before training at that same workload?
Lower heart rate
Which of the following contribute to the observed increase in stroke volume with aerobic training? (choose all that contribute)
increase in ventricular wall thickness increased ventricular internal diameter increase in blood volume
Which of the following is a normal value for stroke volume?
70 mL
Choose the factors from the list below that are an important part of the Frank-Starling mechanism (preload) and lead to increased stroke volume. (choose all that apply)
stretching the sarcomeres to a more optimal length connective tissue adding to tension
Of the factors included in the blood flow (Hagen Poiseuille) equation, which can be quickly changed to help control blood flow around the body? (choose all that apply)
Blood pressure created by the heart Blood vessel diameter/radius
In the average person, cardiac output increases throughout a ramped exercise bout (continued increase in workload). True or False, The continued increase in cardiac output seen between 75 and 100% of VO2max is due to increases in heart rate with no further increase stroke volume.
True
Which of following adaptations are related to the ability of the skeletal muscle to increase extraction of oxygen from the blood stream? (choose all that apply)
Increase myoglobin content Increase capillary density Increased mitochondrial content
RER represents
VCO2/VO2
RER would have a value near ____ when relying heavily on carbohydrate for energy production
1.0
True or False, RER values can be observed above 1.0; this high value is due to acidic by-products of energy production.
True
Cardiac and Type I muscle fibers have many things in common, which of the following is seen in cardiac fibers but not Type I fibers?
Utilized calcium from intra- and extracellular spaces
In the image of a Pacemaker and Action potential above, what ion is responsible for the depolarization in the portion labeled “0”?
Calcium
Phase 0?
Sodium
Phase 1
Potassium
Phase 2
Calcium
Phase 3
Potassium
True or False, cardiac output is defined as the volume of blood pumped out of the heart in one cardiac cycle.
False
Increased resistance in the arterial system would decrease cardiac output. Which of the following mechanisms related to cardiac output deals with the resistance of the arterial system?
increase in afterload
Metabolic Byproducts - How is phosphate Accumulated?
un-bonded phosphates build up in the cells during short intense activity.
Metabolic Byproducts - what does phosphate accumulation interefere with?
Interferes with power stroke. Accumulation in cytosol slows Pi release from myosin heads.
Metabolic Byproducts - Hydrogen Accumulation consists of what?
Lactic Acid Accumulation, which occurs during brief, high-intensity exercises.
Metabolic Byproducts - What happens if Hydrogen isn’t cleared immediately?
Converted into Lactate and H+
Metabolic Byproducts - Hydrogen accumulation causes?
Decrease of musce pH (acidosis).
Metabolic Byproducts - Hydrogen Accumulations - Buffers
Bufers help muscle pH but its not emough. Buffers minimize drop in pH (7.1 to 6.5). Cells can survive but don’t function well.
Metabolic Byproducts - Hydrogen Accumulation - pH < 6.9…
inhibits glycolytic enzymes, ATP synthesis. Glycolytic enzymes slowing them down and not producing ATP as quickly.
Free hydrogen around the filaments…
H+ competes with CA2+ for the binding sits of troponin. Leads to blocking of actin binding sites. Inhibits release fo ADP from myosin head and slowing shortening velocity. Can’t produce as much force!
What happens in Heat accumulation?
High muscle temperature may impair muscle function. Increases rate of carbohydrate utilization and hastens glyogen depletion.
Glycogen Levels in Fatigue?
Glycogen reservs limited and deplete quickly. Depletion corelated with fatigue.
Fatigue - Glycogen levels related to..
total glycogen depletion
Fatigue - Glycogen levels unrealted to
rate of glycogen depletion. Glycogen depletion –> blood glucose.
Fatigue - Glycogen Levels - Depletion and Blood Glucose
- muscle glycogen insufficient for prolonged exercise.
- Muscle will use more blood glucose causing in an increase in liver flycogenolysis and leading to hypoglycemia.
Muscle Glyogen Depletion and Hypoglycemia =
Fatigue
Fatigue - Glycogen Levels - Certain Rate of Muscle Glycogenolysis required to maintain
Oxidative pathways (fat burns in CHO flame)
*** No glycogen = Inhibited substrate oxidation.
Fatigue - Glycogen Levels - With Oxygen Depletion…
FFA Metabolism increases. Fat burns at slow rate. Won’t move as quickly. We want carbohydrate supplemation.
Fatigue - Glycogen Levels - To Limit Carbohydrate Related Fatigue …
One must ingest CHO. If glycogen depleted, you will be fatigued. You want to take carbohydrates throughout a race.
Movement of heart during contraction?
When the heart contracts, it twists up too. Blood thus moved from the bottom and has to exit at the top
Fiber type in the cardiac muscle?
Only one fiber type (similar to type I)
Cardiac Myocyte descriptions
- Higher capillary density
- T tubules are wide but less
- SR is simpler than skeletal
- Numerous large mitochondria (25-35% of cell volume
*
- Numerous large mitochondria (25-35% of cell volume
Cardiac Myocyte Calcium location?
From the inside and outside of the cells
Cardiac Myocyte control type?
Completely involuntary
Cardiac muscle fibers connected by?
Intercalated Discs
Cardiac Myocytes - What are desmosomes and Gap Junctions?
Desmosomes: Hold cells together
Gap Junctions: Rapidly conduct action potentials
Cardiac Myocyte - SA Node
Primary pacemaker. 100 bpm with no input
Cardiac Myocyte - AV Node
Secondary Pacemaker
Connection to Ventricles - 100 milisecond dealy to make sure we ejected enough blood
50 bpm with no input from atrium to ventricles
What is an Electrocariogram (ECG or EKG)
A composite of all the action p otentials generated by nodal an contractile cells at a given time.
Electrodes placed on the skin which monitor electrical changes around many areas of the heart.
ECG - P wave
Artial Depolarization
ECG - QRS Complex
Corresponds with a ventricular depolarization
ECG - T Wave
Repolarization of the ventricles
Cardiac Cycle - Coordinated Control of
Parasympathetic and Sympathetic systems
Cardiac Cycle - Innervation Areas
PArasympathetic - Innvervate SA Node
Sympathetic - Innervate SA Node and Ventricular Muscle
SA Node HR
100 bpm
Normal Sinus Rhythm HR
60 - 100 bpm
~75 bpm
Elite Athlete HR
~ 40 bpm
Bradycardia HR
< 60 bpm
Tachycardia HR
> 100 bpm
HR from lying down to running?
Continues to increase as the intensity increases.
SV from Lying down to Running?
Stroke volume high when lying down then decreases and increases once jogging and running occurs.
CO from lying down to running?
CO lowest at lying down and increases as intensity increases.