Exam 2 Review Flashcards
1
Q
- What are the 3 mechanisms for increasing venous return(blood flow back to right atrium) ?
A
- Increased skeletal muscle activity
- Deep breathing (pulmonary pump)
- Veno constriction (#1 way to increase venous return)
2
Q
- What are the 3 variables that regulate stroke volume? (these 3 also affect cardiac output)
A
- Contractility, venous return (EDV and ESV), Frank Starling effect
3
Q
- How do we regulate heart rate during exercise?
A
- Sympathetic nervous system kicks in releasing hormones like epinephrine (raise HR and BP)
- Central command starts the driv
- Withdrawal of parasympathetic and implementation of sympathetic for exercise
- Withdrawal of sympathetic and implementation of para
4
Q
- Where is the cv control center and where does it receive its information from?
A
- Medulla
- Receives info from chemo(chemical comp of blood)/mechanoreceptors (skeletal muscle)
- Baroreceptors (watch BP)
5
Q
- What are the 2 ways that the cvs responds to the increased demand for 02 during exercise?
A
- Meet the cardiac output(stroke volume x HR) and redistribute blood flow
6
Q
- What are the phases of the heart and how do they change in response to exercise?
A
- Diastole is filling heart (left ventricle/left atrium = high pressure) and Systole is contraction (right ventricle/right atrium = low pressure)
- 2/3 of cycle is filling, and diastole at rest
- Max exercise most is systole, and diastole is drastically reduced
7
Q
- Why is exercise cardio-protective?
A
- Exercise over time reduces wear on the heart and lowers heart rate
- Increase reliance on free fatty acids, can run on alternatives fuels if oxygen isn’t present
- Exercise increases vascular profusion, more capillaries, more pathways for blood (heart attacks or blockage won’t do as much damage because more blood is available)
- More antioxidants
- Improves ability to use oxygen (increased oxygen saturation) which reduces the need for heart to pump more blood
8
Q
- Why does pressure drop across the arterials? How does this impact blood flow during exercise?
A
- Arterioles (high resistance) are last stop before oxygenated blood reaches capillaries which restricts blood flow, making it easier for capillaries.
- Arterioles can maintain or release pressure
- Arterioles hold until metabolic waste tells them to dilate for blood flow
9
Q
- Why does velocity drop across the capillaries? Why is this beneficial?
A
- Gas and nutrient exchange occurs here
- large surface area = slow speeds make it easier to do exchange
- beneficial for diffusion (slow transport time and large surface area)
10
Q
- What are the main contributors to increases in blood pressure?
A
- Heart rate, stroke volume, blood viscosity, and peripheral resistance
11
Q
- What makes up Cardiac Output? How does it change during exercise?
A
- Heart rate x stroke volume (contraction + EDV + mean arterial pressure)
- Cardiac output is dependent on heart rate, so heart rate increases with exercise and so will cardiac output
- Stroke volume only goes up to 40% of max
- Heart Rate goes up linearly till max (linear relationship with cardiac output)
11
Q
- What is double product and why is it determinative of the work of the heart?
A
- Heart (bpm/frequently) x Systolic BP (pressure from heart/how hard)
- Goal is to reduce stress placed on heart with double product as indicator
- Systolic blood pressure tells us how much pressure the heart has to generate with each beat
12
Q
- Why does dynamic upper body exercise increase HR and BP more than comparable lower body exercise?
A
- Upper body exercise means smaller muscles (less pressure relief/high HR and BP),
- Lower body exercise has bigger muscles meaning more pressure relief (more arterioles = higher reductions in HR and BP
- Metabolic waste causes dilation of arterioles , more metabolic waste is produced meaning more arteriole dilation that reduces pressure
13
Q
- What are the primary and secondary functions of the respiratory system?
A
- Primary – gas exchange
- Secondary – pH balance
14
Q
- Explain the role of muscles in breathing. How does this change during exercise?
A
- Diaphragm is used during rest
- External intercostals bring rib cage up during inhalation
- Internal Intercostals bring rib cage down during inhale
- Scalenes and sternocleidomastoid pull upper ribcage during deep inhale
- Abdominal muscles help maintain body during breathing
15
Q
- What factors impact the rate of diffusion?
A
- Blood velocity (slow is better) and surface area
- Driving pressure (difference in pressures between compartments
- Thickness between membranes (distance)
- Transit time (speed of blood)
- Surface area
16
Q
- How is carbon dioxide transported in the blood?
A
- Plasma 10%, bicarbonate 70%, carbamino compounds in hemoglobin 20% (red blood cells)
17
Q
- Explain the limiting factors associated with Alveolar PO2(partial pressure of oxygen).
A
- Alveolar PO2 is 100
- Residual volume (is deoxygenated), fresh air mixes lowering PO2 from 160 to 100
- Deadspace
- Conditioning to air (humidity)
18
Q
- Explain the limiting factors associated with Arterial PO2.
A
- Matching air supply to blood supply
- Imperfect ratio
- Does get better during exercise (because of opening capillaries)
19
Q
- Explain the oxygen dissociation curve and the factors that influence it.
A
- Left shift indicates increased oxygen affinity, right shift is decreased oxygen affinity of hemoglobin meaning more oxygen available to tissues
- Temperature, H ions, CO2
- Deload oxygen in areas with low partial pressure
- High partial pressures is loading hemoglobin
- CO2 decreases hemoglobin’s affinity for oxygen
- Hydrogen is bound to hemoglobin
- Influences
- CO2
- Acid decreases affinity for oxygen
- Temperature
20
Q
- Explain the interaction of myoglobin and hemoglobin and how the oxygen dissociation curves influence this relationship.
A
- Myoglobin has a higher affinity for oxygen and will steal it from hemoglobin
- Only let go near mitochondria
21
Q
- How does ventilation change during exercise?
A
- Ventilation goes up to clear CO2 and meet O2 demands, by increasing tidal volume and breathing frequency
- Low intensity favors tidal volume (decrease work)
- Intense favors breathing rate (
22
Q
- What is ventilation to perfusion matching and how does it change during exercise?
A
- Matching of blood supply to air supply
- Improves tremendously during exercise
23
Q
- How can ventilation impact our VO2 need?
A
- As increased ventilation brings in more oxygen, the demand for O2 increases
- Respiratory muscles work so hard they increase the demand for O2
- Endurance workouts, lungs steal oxygen from muscles
24
26. What is the role of our pleural complex?
* Aids the function of the lungs by preventing lung collapse and ribcage expansion, optimizing their movements together through creating a vacuum
* Balance the pressures in the vacuum
25
27. Explain what an acid is. Now explain what a base is.
* Acids (donor) release hydrogen and bases (adopts) remove H (accept)
26
28. What are the intracellular buffers?
* Cellular proteins, Bicarbonate, phosphate
27
29. What are the extracellular buffers?
* Bicarbonate, hemoglobin, blood proteins
28
30. Why are H+ ions damaging to performance?
* They mess with muscle contraction, decrease force output, reduce effectiveness of energy systems
* Inhibit key enzymes to energy production, interfere with Calcium release and reuptake, competes with Calcium ions for bonding sites on troponin and myosin, interferes with cross-bridge cycling
29
What is tidal volume? Where does it start and what's the volumes?
* Tidal Volume – normally breathing: starts at 2500 to 3kmL (500mL coming in and 500 mL going out)
o peak is inspiration
o bottom expiration
30
What is the difference between IRV and ERV?
* IRV (Inspiratory Reserve Volume) – forceful intake of air beyond tidal volume (2800-3100mL)
* ERV (Expiratory Reserve Volume) – forceful exhale of air beyond tidal volume (13-1200mL)
31
What is the purpose of RV and what is its volume?
its the air that remains in the lungs to keep alveoli open (1200mL)
32
What's the difference between IC and EC?
* IC (Inspiratory Capacity) – total amount of air during intake (TV + IRV)
* EC (Expiratory Capacity) – total amount of air during expiration (TV + ERV)
33
What's the difference between FRC and VC?
* FRC (Functional Residual Capacity) – (ERV + RV)
* VC (Vital Capacity) - total volume of air that can be brought in and exhaled forcefully (IRV + TV + ERV)
34
What makes up TLC? How much volume?
TV + ERV + IRV + RV = 5800mL
35
How does training reduce exercise ventilation?
less H production, better H buffering, less afferent muscle feedback, greater efficiency
36
What is the relationship with CO2 and pH in the oxygen association curve?
High CO2 = low pH and vice versa
37
What happens to pH balance during exercise?
during exercise body leans toward acidic environment (low pH), H is indicator of pH, more intense exercise causes more H
38
What are the sources of H during exercise
production of CO2, production of lactate/lactic, and ATP breakdown
39
what 3 factors determine the degree of pH disturbance
intensity, amount of muscle, duration
40
How does the body protect from H
buffering, respiratory influence (bicarbonate buffer), Kidneys
