MAPIISG1 - O2 Transportation Flashcards
What is DO2 = artieral O2 x CO?
Oxygen Delivery
With an increase in demand at the tissue, what happens to Oxygen Delivery (DO2)?
Normally based on demands of tissues (CO2 increases with increase in demand)
T/F: At rest Oxygen Delivery (DO2) = demand.
False: at rest, DO2 is 3-4x greater than demand
How is 98% of O2 transported?
in association with hemoglobin (Hgb)
Hgb affinity for O2 determined by ___ (3)
pH, temp, PCO2
changes produce shifts in oxyHgb dissociation curve
What is VO2 = arterial O2 - vO2 x CO?
Oxygen Consumption
What may happen to Oxygen Consumption (VO2) if there is a severe cardiopulmonary dysfunction?
it may fall short of demand
What is OER = VO2/DO2
Oxygen Extraction Ratio = Consumption / Delivery
What is Oxygen Extraction Ratio (OER) at rest?
~23%
What three factors are looked at with inspired oxygen and quality of air?
- Atmospheric Air
- Air Quality
- Humidity
Atmospheric Air:
__% O2
__% Nitrogen
__% CO2
Atmospheric Air:
21% O2
79% Nitrogen
0.03% CO2
What effect will poor air quality have on the respiratory system?
Poor air quality interferes with respiratory tract filtering – lead to inflammation of alveolar capacity.
What role does humidity play in respiration? Effects of a dry environment?
In alveoli, inspired air saturated with water vapor.
Dry environments: loss of mucous covering, erosion, and infection
What muscles are used for active inspiration and how? (2)
Diaphragm - dress the inferiro wall of the thoracic cavity, and therefore, increase volume.
External intercostals- elevate ribs and therefore increase the volume.
What muscle are used for normal expiration?
normally passive due to elastic force of lungs.
What muscles are used for forced expiration and how? (2)
Internal Intercostals - compress and lower the ribs and therefore decrease volume.
Abdominals - compress the abdonimal cavity elevating organs and diaphragm therefore decreasing volume.
What five things is diffusion of O2 from alveolar sacs to pulmonary arterial circulation based on?
- Surface area of alveolar capillary membrane.
- Diffusing capacity of alveolar capillary membrane
- Pulmonary capillary blood volume
- Ventilation/perfusion ratio
- Transit time of blood in alveolar capillary membrane
Diffusion of O2 varies directly with ____ and indirectly with ____.
Diffusion of O2 varies directly with SURFACE AREA OF ALVEOLI and indirectly with THICKNESS OF ALEVOLAR-CAPILLARY MEMBRANE.
When upright, where is perfusion in the lungs optimal?
around horizontal midline of lungs
What is Ventilation (V) / Perfision (Q)?
~0.8
Myocardial function: optimal with synchronized ____ and ____.
Myocardial function: optimal with synchronized ELECTRICAL COUPLINE and MECHANICAL CONTRACTION.
Define Preload
Preload is the filling pressure of the heart at the end of diastole. The left atrial pressure (LAP) at the end of diastole will determine the preload.
The greater the preload, the greater will be the ___
volume of blood in the heart at the end of diastole.
Inotropic effect is ___ while Chronotropic effect is ___.
Inotropic effect is FORCE while Chronotropic effect is RATE OF CONTRCTION.
Define Afterload
Afterload is the pressure in the wall of the left ventricle during ejection. In other words, it is the end load against which the heart contracts to eject blood
What is a normal ejection fraction?
55-70%
This and HR can be used to measure impairment
Large vessels ted to have more ___, while medium to small vessels have more ___.
Large vessels ted to have more ELASTIC AND CONNECTIVE TISSUE, while medium to small vessels have more SMOOTH MUSCLE.
What is the purpose of arterioles?
Regulate blood flow thru regional vascular beds
Does O2 diffusion occur slowly or quickly
quickly
What does intracellular PO2 average?
23 mmHg
What PO2 is needed for cell metabolism?
3 mmHg
Is rate of O2 extraction regulated by availability or demand?
demand
What are 4 normal factors that “shake up” O2 transport?
- Activity
- Position (i.e. gravity)
- Emotion
- Stress
What are 6 disease factors that “shake up” O2 transportation?
- Bedrest
- Fever
- Disease Itself
- Inflammation Process
- Medication
- Fluid Imbalance
What effected does restricted/reduced activity on CO? VO2? OER?
Decrease in CO, VO2, OER and impacts multiple other systems
What 4 effects does bed rest have?
- Changes in fluid distribution
- Decrease in muscle activity
- changes in body weight distribution and pressure
- aerobic deconditioning and all that impacts with oxygen transport/exchange
What 2 effects does a loss of gravitation stress have on the body?
- Fluid shift from body/legs to thorax head
2. Musculoskeletal changes
What are 3 external signs of oxygen transport dysfunction?
- Skin: pale, cyanotic, cold
- Speech: short of breath
- Diaphoresis: sweating
What are 5 internal signs of oxygen transport dysfunction?
- Vital signs
- Respiratory patterns
- Hypoxia/low pulse oximetry
- Poor peripheral circulation
- Decrease capillary refill (>3 sec)
