Term
| What is pulmonary respiration? |
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Definition
| Ventilation (breathing) and the exchange of gases (O2 & CO2) in the lungs |
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Term
| What is cellular respiration? |
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Definition
| Relates to O2 utilization and CO2 production by the tissues |
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Term
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Definition
| mechanical process of moving air into and out of the lungs |
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Term
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Definition
| Random movement of molecules from an area of high concentration to low concentration. |
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Term
| What 3 things does the conducting zone consist of? What is it's job? |
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Definition
1) Trachea
2) Bronchial tree
3) Bronchioles
Conducts air to respiratory zone. Humidifies, warms, and filters the air. |
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Term
| What 2 things does the respiratory zone consist of? What is it's job? |
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Definition
1) Respiratory bronchioles
2) Alveolar sacs
Exchange of gases between air and blood |
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Term
| List and define the 3 mechanics of breathing: |
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Definition
1) Inspiration - Diaphragm pushes downward, lowering intrapulmonary pressure
2) Expiration - Diaphragm relaxes, raising intrapulmonary pressure
3) Resistance to airflow - Largely determined by airway diameter. |
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Term
| What is pulmonary ventilation and what is the equation used to determine it? |
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Definition
| Pulmonary ventilation is the amount of air moved in or out of the lungs per minute. V = Tidal Volume x breathing frequency |
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Term
| What is dead-space ventilation? What is alveolar ventilation? |
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Definition
Dead-space ventilation is unusable. "unused ventilation". Does not participate in gas exchange. Anatomical dead space: conducting zone. Physiological dead space = disease.
Alveolar ventilation - Usable. Volume of inspire gas that reaches the respiratory zone.
V = Va + Vd |
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Term
1)vital capacity?
2)residual volume?
3)total lung capacity?
4)inspiratory reserve volume?
5)expiratory reserve volume? |
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Definition
1)vital capacity - maximum amount of air that can be expired following a maximum inspiration
2)residual volume - Air remaining in the lungs after a maximum expiration
3)total lung capacity - vital capacity + residual volume
4)inspiratory reserve volume - volume of gas that can be inspired at the end of a tidal inspiration
5)expiratory reserve volume - the volume of gas that can be expired at the end of a tidal expiration |
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Term
| Explain partial pressure of gases (calculaiton): |
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Definition
The total pressure of a gas mixture is equal to the sum of the pressure that each gas would exert independently .
Calculation:
% of air(O2/CO2) x total pressure of air
PO2 = 0.2093 O2 x 760 mmHg = 159 mmHg |
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Term
| What 3 things effect the diffusion of gases? (Fick's law of diffusion) |
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Definition
1) The tissue area
2) The diffusion coefficient of the gas (chemical property)
3) The difference in partial pressure (gradient)
Rate of diffusion = (Tissue Area)/(Tissue Thickness) x Diffusion coefficient of gas x (difference in partial pressure)
so
Vgas = A/T x D x (P1 - P2) |
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Term
| Starting at the alveoli, how does the partial pressure of oxygen fluctuate between the pulmonary vein, systemic artery, systemic veins, and pulmonary artery |
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Definition
PO2 in the capillaries = 105
PO2 in the pulmonary vein = 100
PO2 in the systemic arteries = 100
PO2 in the systemic veins = 40
PO2 in the pulmonary artery = 40 |
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Term
| Starting at the alveoli, how does the partial pressure of CO2 fluctuate between the pulmonary vein, systemic artery, systemic veins, and pulmonary artery |
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Definition
PCO2 in the alveoli = 40
PCO2 in pulmonary vein = 40
PCO2 in systemic arteries = 40
PCO2 in Systemic veins = 46
PCO2 in pulmonary artery = 46 |
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Term
| With regards to blow flow to the lung, where is most of the blood flow when standing? What about supine (laying down)? |
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Definition
When standing, most of the blood flow is to the base of the lung due to gravitational force.
When supine, blood distribution is proportional. |
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Term
What is the ventilation perfusion ratio?
Base vs. Apex |
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Definition
(V/Q L/min) Indicates matching of blood flow to ventilation.
Base is overperfused (ratio <1.0), disproportionately high ventilation relative to blood flow = poor gas exchange
Apex is underperfused (ratio > 1.0), greater blood flow then ventilation. Adequate so long as ratio exceeds 0.5 |
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Term
| Apporximately 99% of O2 transported in the blood is bound to __________. |
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Definition
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Term
What is oxyhemoglobin?
What is Deoxyhemoglobin? |
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Definition
Oxyhemoglobin - Hemoglobin with bound O2
Deoxyhemoglobin - Hemoglobin without bound O2 |
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Term
| The amount of O2 transported per unit volume of blood depends on what? |
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Definition
| hemoglobin concentration which is generally a function of red blood cell count in healthy individuals |
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Term
| What are the two affecting variables in O2 transport in the blood? |
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Definition
1) PO2 of blood
2) Bond strength of hemoglobin and O2 |
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Term
| What happens to pH during exercise and how does pH effect the oxyhemoglobin dissociation curve? |
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Definition
Blood pH declines during heavy exercise which results in a "rightward" shift of the curve (increased "sensitivity")
-Bohr effect
-Favors "offloading" of O2 to the tissues |
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Term
| How does temperature effect the oxyhemoglobin dissociation curve? |
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Definition
Increased blood temperature results in a weaker Hb-O2 bond. This results in a rightward shift of the curve.
-Easier "offloading" of O2 at tissues |
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Term
What aids the O2 transport in muscles?
How does the affinity of myoglobin for O2 compare to hemoglobin? |
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Definition
Myoglobin shuttles O2 from the cell membrane to the mitochondria.
Myoglobin has a higher affinity for O2 than hemoglobin even at low PO2. This allows for myoglobin to store O2. |
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Term
| Myoglobin - O2 dissociation is important why? |
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Definition
| Because it ensures O2 delivery from the blood to the cell. It is essential for survival and exercise performance |
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Term
| With regards to CO2 transport in the blood, what 3 places can CO2 go? |
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Definition
1) Dissolved in the plasma (10%)
2) Bound to hemoglobin (20%)
3) Bicarbonate (70%) |
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Term
| Which 2 ways can CO2 be released from the blood? |
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Definition
1) HCO3 -> H2CO3 -> H20 + CO2
2) Bicarbonate -> Carbonic acid -> water + CO2 |
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Term
| With regards to rest-to-work transitions, what happens with ventilation, PCO2, and PO2? |
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Definition
Ventilation - initially increases rapidly then, a slower rise toward steady-state
PO2 - maintained
PCO2 - maintained |
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Term
| What effect does incremental exercise have on ventilation? |
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Definition
| Ventilation - linear increase up to 50-75% VO2 max. Once ventilatory threshold is met, there is an exponential increase |
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Term
| With regards to exercise, what is the effect on PO2, pH, and ventilatory threshold in trained vs untrained individuals? |
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Definition
In the trained runner, there is a decrease in arterial PO2 near exhaustion.
pH maintained at a higher work rate
Ventilatory Threshold occurs at a higher work rate. |
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Term
| What is the respiratory control center? |
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Definition
(brain, brain stem) - receives neural and humoral (blood content) input
-Feedback from muscles
-CO2 level in the blood |
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Term
| What two types of chemorecptors help to control the respiratory control center? |
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Definition
1) Humoral Chemoreceptors -
-Central chemoreceptors located in the medulla. PCO2 and H+ concentration in cerebrospinal fluid
-Peripheral chemoreceptors - Aortic and carotid bodies. PO2, PCO2, H+, and K+ in blood
2) Neural input - from motor cortex or skeletal muscle |
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Term
| What effect does exercise in a hot environment have on Ventilation and PCO2? |
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Definition
During prolong submax exercise:
Ventilation - tends to drift upwards
PCO2 - little change.
Higher ventilation is not due to increased PCO2 |
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Term
| On a graph, what effect does arterial PCO2 have on ventilation? |
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Definition
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Term
| What effect does arterial PO2 have on ventilation? |
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Definition
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Term
| Do the lungs limit exercise performance? |
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Definition
For low to moderate intensity exercise, the pulmonary system is not seen as a limitation.
For Maximal exercise, it is not thought to be a limitation in healthy individuals at sea level. It may be limiting in elite endurance athletes. New evidence shows that respiratory muscle fatigue does occur during high intensity exercise. |
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Term
During submaximal exercise, what happens to ventilatory control? What is this due to?
What about during Heavy Exercise? |
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Definition
Linear increase due to
1) central command (brain, brain stem)
2) humoral chemoreceptors (biochemical factors)
3) neural Feedback
During heavy exercise, there is an exponentail rise above the ventilatory threshold. Increasing blood H+ |
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Term
| What is the effect of training on ventilation? |
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Definition
Ventilation is lower at the same work rate following training.
May be due to lower blood lactic acid levels
-Results in less feedback to stimulate breathing. |
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Term
| What are the effects of endurance training on ventilation during exercise? |
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Definition
| You have better ventilation before endurance training than after endurance training. Weird concept and we don't really know exactly why. |
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Term
What are the 2 causes of exercise induced hypoxemia?
What population does this effect? |
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Definition
Causes:
1) Ventilation-perfusion mismatch
2) Diffusion limitations due to reduce time of RBC in pulmonary capillaries due to high cardiac outputs.
A large minority (up to 50%) of male and female endurance athletes can develop exercise-induced hypoxemia. |
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Term
Define an acid:
Define a base:
Define pH:
What is a noraml pH? Acidosis? Alkalosis?
What pH is the survival range? |
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Definition
Acid - molecule that can liberate(donate) H+ ions
Base - molecule that is capable of combining (receiving) with H+ ions
pH - measure of H+ ion concentration
Normal pH - 7.4
Acidosis - ph<7.4
Alkalosis - pH>7.4
Survival range - 7.0 - 7.8 |
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Term
| What are 3 sources of H+ ions during exercise? |
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Definition
1) Volatile acids - major contributor during acute exercise (particularly high intensity) - CO2 (carbonic acid, H2CO3)
2) Fixed acids - minor contributor during acute exercise - Sulfuric acid and Phosphoric acid
3) Organic acids - converted to CO2 (buffer process) - Lactic acids are a major contributor during acute high intensity exercise |
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Term
What happens to Blood pH with increased intensity exercise?
In comparison, what happens to Muscle pH with increased intensity exercise? |
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Definition
Blood pH declines with increasing intensity exercise
Muscle pH declines more dramatically than blood pH - site of H+ production, muscle has lower buffering capacity. |
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Term
List the 3 intracellular buffering systems.
List the 3 extracellular buffering systems. |
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Definition
Intracullular
1) Proteins
2) Phosphate groups
3) Bicarbonate
Extracellular
1) Bicarbonate
2) Hemoglobin
3) Blood proteins |
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Term
| During exercise, what changes do you see in lactate? Bicarbonate? and pH? |
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Definition
lactate - steady then increases
bicarbonate - decreases
pH - decreases |
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Term
| What is the roles of the lungs and kidneys in pH regulation? |
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Definition
lungs - increased PCO2 results in low pH, increases ventilation, CO2 is "blown off", pH lowered
Kidneys - not essential during acute exercise. Regulates blood bicarbonate concentration and is important in long-term acid-base balance. |
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Term
Define:
Radiation
Conduction
Convection
Evaporation |
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Definition
Radiation - (60% heat loss at rest) - transfer of heat via infrared rays, no physical contact between surfaces
Conduction - Heat loss due to contact with another surface
Convection - Form of conductive heat loss. Heat transferred to air or water.
Evaporation - (25% heat loss at rest) - heat transferred via water (sweat) on skin surface. Evaporation rate depends on 1)Temp and relative humidity 2)Convective currents around the body 3)amount of skin surface exposed. This is the Most important means during exercise! |
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Term
| What is the body's response to heat stress? |
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Definition
| Anterior hypothalamus -> Commencement of sweating and increased skin blood flow (cutaneous vasodilation) |
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Term
| What is the body's responses to cold stress? |
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Definition
| Posterior hypothalamus -> increase heat production through shivering and decrease heat loss through decreased skin blood flow or (Cutaneous vasoconstriction). Also, catecholamine release and thyroxin release aid in conserving heat. |
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Term
| What 3 ways is heat exchanged during exercise? |
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Definition
1) Evaporative heat loss - most important means of heat loss!!
2) Convective heat loss - small contribution
3) Radiative heat loss - small role in total heat loss |
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Term
Higher temperatures increases evaporation, conduction, and radiation.
How is core temperature and sweat rate effected by heat and humidity? |
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Definition
| The higher the humidity and heat, the higher the core temperature and sweat rate. Inability to lose heat can result in impaired performance and hyperthermia |
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Term
| What 5 things factor in to heat acclimatization? |
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Definition
1) Increased plasma volume
2) Earlier onset of sweating
3) Higher sweat rate
4) Reduced sodium chloride loss in sweat
5) Reduced skin blood flow |
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Term
| With regards to the oxyhemoglobin dissociation curve, what characterizes the slower O2 delivery portion and what characterizes the rapid O2 delivery poriton? |
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Definition
Slower O2 delivery = > 40mmHgPO2. Due to high altitude, aged
Rapid O2 delivery = < 40mmHgPO2. Due to exercise "sensitive" |
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