Ex. Phys. Respiratory System Flashcards

Question

success of gas exchange is dependent upon | NOT ON TEST

Answer 1

adequate total ventilation (VE) and alveolar ventilation (VA)

Answer 2

VE: it is the volume of air that enters the lungs each minute VA: volume of air that enters the actual alveoli each minute

Answer 3

remember that EV = VT x f about 150 ml of VT is dead space (DS) -air in the bronchial pathways that does not participate in gas exchange VA = (VT - DS) x f VA is important, then, in terms of pulmonary function

Answer 4

shallow, rapid breathing minimizes VA slow, deep breathing maximizes VA aerobic exercise is a balance between the rate and depth of breathing to obtain an adequate VA

Answer 5

integrated processes that sustain metabolism

Answer 6

- loading O2 into the blood on hemoglobin from the alveoli - removing CO2 from the blood to the alveoli - transporting O2 to the tissues and unloading in onto myoglobin - loading CO2 from the tissues into the blood and transporting it to the alveoli

Answer 7

Hb is the iron-containing O2 transport protein found in all RBCs - initially accepts O2 during gas exchange at the lungs - also can transport CO2 from the tissues to the lungs for gas exchange - each Hb molecule can bind up to 4 O2 molecules - -with each O2 that binds, Hb's affinity for O2 increases

Answer 8

iron-containing O2 transport protein found in all muscle tissue -accepts O2 during gas exchange at the muscles

Answer 9

O2 diffuses from alveoli into RBC -within RBC, O2 binds to Hb Hb carries 95% of all the O2 that diffuses into blood remaining 5% of diffused O2 is dissolved in the blood (PO2) -although small, this is important because it is used to monitor ventilation (primary) once carried to the muscles, increases 2,3-Bisphosphoglycerate (2,3-BPG), H+, CO2, and temperature induce O2 loading into the muscles O2 unloaded into muscles onto Mb for use in mitochondrial respiration

Answer 10

describes how CO2 and H+ affect the affinity of Hb for O2 | high CO2 and H+ concentrations decrease affinity for O2, while low concentrations increase affinity for O2

Answer 11

in active muscles, CO2 and H+ levels are high oxygenated blood that flows past is affected by these conditions, and the affinity of Hb for O2 is decrease, allowing O2 to be more easily transferred to the muscles

Answer 12

CO2 diffuses from the muscle into RBC 90% of CO2 is converted to H+ and bicarbonate (HCO3-) using the following reaction -CO2 + H2O --> H+ + HCO3- -HCO3- binds to Hb for transport to lungs H+ "buffered" via binding to Hb in the RBC and to specific blood plasma proteins -this reaction is important because sizeable amounts of CO2 can be transported in the blood to the lungs without substantially altering blood pH -at lungs, the above reaction is reversed to produce CO2 and H2O, which diffuses into alveoli and is expired

Answer 13

5% of CO2 is directly bound to and carried by Hb 5% of CO2 is dissolved in blood (PCO2). again, this is very important because it is what is monitored for ventilation regulation

Answer 14

describes how O2 concentrations determine Hb affinity for CO2 ex. -high O2 concentrations enhance the unloading of CO2 -converse is true: low O2 concentrations promote loading of CO2 onto Hb in both situations, it is O2 that causes change in CO2 levels

Answer 15

in the lungs, when Hb loaded with CO2 is exposed to high O2 levels, Hb's affinity for CO2 decreases

Answer 16

``` partial pressure gradients barriers to diffusion RBC transit time Hb and Mb concentrations Bohr and Haldane effects ventilation/perfusion ratio ```

Answer 17

``` surfactant alveolar epithelium interstitial space capillary basement membrane capillary endothelium ```

Answer 18

within capillary, transit time is 0.75 sec at rest, down to 0.25 sec with maximal exercise -at maximal exercise, Hb desaturation occurs, which can make the muscles ischemic

Answer 19

the more Hb that is present in the blood (typically due to increased RBC concentrations), the more O2 that can be carried to the muscles the more Mb that is present in the muscle, the more O2 than can be accepted into the muscles

Answer 20

calculated as VA/Q represents the relative efficiency of gas exchange from the alveoli to the blood -an ideal score is around 1.0 score variation -lung blood flow varies from the base to the apex, so VA/Q changes depending on region -really high or really low values typically imply some sort of ventilatory pathophysiology, such as chronic bronchitis, asthma, or COPD

Answer 21

``` ventilatory centers (medulla and pons) in the brain initially adjust ventilation via a feed forward system sensory receptors through the body adjust ventilation via feedback systems ```

Answer 22

primary responsibility for an anticipatory rise in VE | SNS dilates bronchioles to increase airflow into lungs

Answer 23

mechanoreceptors in muscles often elicit rapid rises and sudden drops in VE due to increases or absence of physical motion chemoreceptors in the blood vessels are responsible for slow plateaus and gradual declines in VE during sustained exercise or periods of rest

Answer 24

PCO2, blood pH, LA, epinephrine and norepinephrine, temperature, etc. -PCO2 is the primary