Midterm 2 review Flashcards
- Define pulmonary ventilation, external respiration, and internal respiration. Define the following variables and classify each as involved in pulmonary ventilation, external respiration, or internal respiration. Some may be classified in more than one way.
(A-a) PO2diff, PAO2, a-VO2diff, PaCO2, PvCO2, PVO2, SaO2%, PaO2, VA, VE, VD
Pulmonary Ventilation: Movement of air in and out of lungs
External Respiration: exchange of gases between the alveoli of lungs and blood
Internal Respiration: Exchnage of gases between blood and tissue of body
Pulmonary: VA, VE, VD
External: (A-a) PO2diff, PAO2, PaCO2, SaO2%, PaO2,
Internal: a-VO2diff, PvCO2, PvO2,
Name these variables: (A-a) PO2diff, PAO2, a-VO2diff, PaCO2, PvCO2, PVO2, SaO2%, PaO2, VA, VE, VD
(A-a)PO2diff: Alveolar arterial oxygen gradient
PAO2: alveolar O2
a-VO2diff: Arteriovenous oxygen difference
PaCO2: Arterial CO2
PvCO2: Venous CO2
PvO2: Venous O2
SaO2%: Saturation of O2
PaO2: Arterial O2
VA: Alveolar ventilation
VE: Minute ventilation
VD: Dead space ventilation
Identify the three capacities and four volumes into which total lung capacity can be divided. Which of them is most responsive during exercise?
Capacities:
Total Lung Capacity
Inspiratory Capacity
Vital Capacity
Volumes:
Tidal Volume
Inspiratory Reserve Volume
Expiratory Reserve Volume
Residual Volume
During exercise:
Tidal volume will increase to increase oxygen intake and in turn so will IRV for deeper and more resourceful inhales
Discuss the primary control of respiration and the factors that affect such control. How does this impact the ability to achieve steady state respiratory during submaximal exercise?
Primary control of respiration:
- Neural control from the brainstem. Medulla contain DRG and VRG
DRG:
- rhythm of breathing
-Chemoreceptors detect changes in pH, and PCO2, PO2
VRG: integrates input and adjusts respiratory activity
Steady State would be achived when the neural control of the brain can coordinate O2 deliver to match metabolic demands. This would be done through constant submaxiaml work and would lead to a steady respiratory rate. During submaximal exercise the respiratory system is making up to deliver blood to working muscles. The respiratory centers in the brain increase ventilation by detecting changes inPCO2, PO2 pH.
Describe how oxygen and carbon dioxide and transported in the circulatory system.
Oxygen:
- In physical solution dissolved in fluid portion of blood
- In loose combination with Hb, the iron-protein molecule within the RBC
CO2:
- dissolved in the blood
- as bicarbonate
- bound to Hb
Graph a normal resting oxygen dissociation curve. What percentage of the available oxygen is normally dissociated at rest? What changes during exercise and altitude in regarding to oxygen dissociation?
Approx 25% oxygen is disassociated at rest
List and explain the four factors that increase oxygen dissociated during exercise. How would this impact the dissociation of oxygen and why would this be beneficial during exercise? Describe the additional factor that influences oxygen dissociation at altitude
- Increased metabolic rate (O2 gradient)
Body need more O2 therefore O2 will disassociate from HB - Increase in CO2 (pH)
Need more O2 to make sure blood isnt too acidic
3.Increased temp
shifts oxyhemo curve to the right - Increased blood flow or 2,3 DPG
Altitude:
Hypoxia influences at high altitude bc ventilation and EPO increased so more unbinding of O2 to needed tissue
Compare and contrast the pulmonary ventilation, external respiration and internal respiration responses to short-term, light to moderate submaximal exercise; long-term moderate to heavy submaximal aerobic exercise; incremental aerobic exercise to maximum and static exercise.
Short term, light to moderate:
- Pulmonary: Small increase in pulmonary minute ventilation
- External: Gas exchange is enchanched only slightly
- Internal: gas exchange btwn blood and tissue is also increased to meet demands
Long term, moderate to heavy
- Pulmonary: ventilation increased signifigantly to meet demands
- External: external is enhanced long term and gass exchange is effecuent
- Internal: Increased gas delivery to tissue and CO2 removal. O2 delivery and utilization is balanced
Incremental to max and static
- Pulmonary:Ventilation has 2 breakn points, one at 50-75% and one at around 80-85%, ventilatory thresholds
- External: increased and at max effeciency
- Internal: bodys primary muscles are recieving o2 supply
Explain exercise-induced hypoxemia (EIAH) and the physiological theories that have been implicated in its occurrence. What other factor may indicate respiratory limitation to maximal exercise?
EIAH occurs in about 50% of high;y trained males and >60% of highly trained females.
The factors that cause EIAH are
1. Right to left shunting of blood
2. Relative alveolar hypoventilation
- Possibly:
1. Reduced sensitivity to ventilatory stimuli such as PaO2, [K+], [H+], PaCO2, circulating catecholamines
2. Airway flow limitations (encroachment of tidal volume on the maximal flow-volume loop (generally expiratory flow limitation)
3. Airway narrowing (partial collapse during exercise)
- ventilation perfusion mismatch
- the lung is not a perfect gas exchange organ:
- there are areas of the lung that are better perfused and areas that are better ventilated
- e.g. partial or complete collapse of airways and/or pulmonary capillaries leads to inadequate ventilation and/or perfusion of areas
- generally: upper portions (apex) of lungs are better ventilated and poorly perfused and lower portions (base) of lung is better perfused and poorly ventilated
- diffusion limitation
- two major possibilities:
1. decreased RBC transit time due to increased QC
a. remember that highly trained athletes may have a QC > 30 L/min at peak exercise – all of which also has to go through the pulmonary circulation each minute
2. mild interstitial pulmonary oedema due to increased pulmonary capillary pressures à Leakage
a. rupture of the membrane (stress failure)\
b. leakage over time (increased permeability)
- two major possibilities:
Acute ozone exposure can affect oxygen consumption and maximal performance.
- The exposure you would get from cars directly would be sulfur dioxide, nitrogen oxide, ozone particulates, and carbon monoxide
- Also the risk of inhaling prticles which can decrease performance for more than one day
Why is maximal oxygen consumption considered to be a cardiovascular variable?
Bc it refelcts maximum amount of O2 taken up by the muscles. The O2 is transported through the blood stream and this number is reliant on the speed of the blood to the tissues whihc is all based on cardiovascular variables
What is the most likely physiological system limiting maximal oxygen consumption? What are some lines of evidence that suggest this is the case?
Cardiac output is considered to be the limiting factor in VO2 max. The evidence is that the cardiorespiratory systems cannot keep up the O2 delivery to muscles.
Graph and explain the pattern of response for each of the major cardiovascular variables during short-term, light to moderate aerobic exercise. Explain the mechanisms responsible for each response
Cardiac Output (Q): Q increases due to increase in venous return which increases EDV and sympathetic activity decreases ESV
SV: SV increases in relation with Q
HR: : HR increases due to parasympathetic withdrawal and eventually sympathetic increase
BP: SBP increases due in increase in Q
TPR: Total peripheral resistance decreases because of vasodilation in the active muscles
RPP:
Graph and explain the pattern of response for which of the major cardiovascular variables during long-term, heavy aerobic exercise. Explain the mechanisms responsible for each response.
Q: increases then plateaus
SV: SV has an initial increase, plateaus and then has a negative drift after 30 min
HR: HR initially increases, plateaus at steady state and then has a positive drift. Increase in HR proportional to decrease in SV
BP: SBP has an initial increase, plateau at steady state or slight drift downwards due to continued vasodilation
TPR: TPR decreases rapidly, plateaus and then had a slight negative drift because of vasodilation
RPP: RPP increases higher due to higher SBP and HR
Graph and explain the pattern of response for each of the major cardiovascular variables during incremental aerobic exercise to maximal. Explain the mechanisms responsible for each response.
Q: reticular increase with plateau at max
SV: increases initially plateaus at 40-50% max.
HR: retiticlinear increase with increase at max
BP: Increase with plateau at max
TPR: curvilinear decrease
RPP: rectilinear increase w plateau at max
Static:
Q: Modest gradual vibes
SV: relatively constant at low reduction in SV results from a lower venous return and therefore EDV due to an increase in intrathoracic pressure and a lower ESV due to greater arterial pressure which reduces the ejection of blood workloads. Decreases at high workloads
HR: Modest gradual increase
BP: Marked steady increase
TPR: Decreases
RPP: Marked steady incase
