Oxygen is carried in the blood in what two forms?
1) as dissolved oxygen in the blood plasma 2) Chemically bound to the hemoglobin
What is the definition of dissolve?
when a gas like oxygen enters the plasma, it maintains its precise molecular structure and moves freely throughout the plasma in its normal gaseous state
To determine the total amount of oxygen in 100 mL of blood what must be added together?
the dissolved oxygen and the oxygen bound to hemoglobin
List the factors that cause the oxygen dissociation curve to shift to the left.
1)increase pH 2) decreased PCO2 3) decreased temperature 4) Decrease DPG 5) HbF 6) COHb
List the factors that cause the dissociation curve to shift to the right.
1)decreased pH 2)Increased PCO2 3)increased temperature 4) increased DPG
The total amount of O2 delivered or transported to the peripheral tissues is dependent on what three things?
1)The body's ability to oxyygenate blood 2)the hemoglobin concentration 3)the cardiac output Do2= QT ×(CaO2×10)
Oxygen delivery decreases when there is a decline in what 3 things?
1)blood oxygenation 2)hemoglobin concentration 3)cardiac output
The amount of oxygen extracted by the peripheral tissues during the period of 1 minute
the amount of oxygen extracted by the peripheral tissues divided by the amount of O2 delivered to the peripheral cells
Oxygen extraction ratio
the portion of cardiac output that moves from the right side to the left side of the heart without being exposed to alveolar O2
exists when blood flows from the right side of the heart to the left side without coming in contact with an alveolus for gas exchange
What abnormalities cause anatomic shunting?
Congenital heart disease, Intrapulmonary fistula, and vacular lung tumors
A Capillary shunt is commonly caused by what?
Alveolar collapse or atelectasis, alveolar fluid accumulation, or alveolar consolidation
Common causes of a relative shunt
hypoventilation, ventilation/perfusion mismatches, and alveolar-capillary diffusion defects
The end result of pulmonary shunting and is the mixing of shunted, non-reoxygenated blood with reoxygenated blood distal to the alveoli
Pulmonary shunting below ____% reflects normal lung status. A shunt between_______% is indicative of an intrapulmonary abnormality,but is seldom of clinical significance. Pulmonary shunting between _______% denotes significant intrapulmonary disease and may be life threatening.
10; 10 and 20; 20 and 30
Common causes of a decreased PaO2
1) a low alveolar oxygen tension 2) diffusion defects 3) ventilation-perfusion mismatchses 4) pulmonary shunting
Anemia Hypoxia can develop from what?
1) a low amount of hemoglobin in the blood 2) a deficiency in the ability of hemoglobin to carry oxygen
Circulatory Hypoxia ( also called stagnant or hypoperfusion hypoxia)
the arterial blood that reaches the tissue cells may have a normal oxygen tension and content, but the amount of blood and, therefore, the amount of oxygen is not adequate to meet tissue needs
Causes for Circulating hypoxia
1) slow or stagnant peripheral blood flow and 2) arterial-venous shunting
Develops in any condition that impairs the ability of tissue cells to utilize oxygen