45 terms

Chapter 6- Cardiopulmonary A&P

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
About ______ mL of oxygen will dissolve in 100 mL of blood for every 1 mm Hg of P02
0.003 mL
A relatively small percentage of oxygen is transported in the form of what?
dissolved oxygen
Each RBC contains approximately how many hemoglobin molecules?
280 million
Normal adult hemoglobin consists of what?
1) four heme groups 2) four amino acid chains
hemoglobin that is bound with oxygen
hemoglobin not bound with oxygen
reduced hemoglobin or deoxyhemoglobin
Normal hemoglobin value for adult male
14 to 16 g/100 mL
The average adult female hemoglobin value
12 to 15 g%
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
What is the formula for CaO₂? (oxygen content of aterial blood)
What is the formula for CVO₂? (Oxygen content of mixed venous blood)
What is the formula for CcO₂? (Oxygen content of pulmonary capillary blood)
What is the normal P50?
about 27 mmHg
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
What happens when the curve shifts to the right?
more O2 is being released into the tissues
What happens when the curve shifts to the left?
less O2 is being released into the tissue
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)
What is the normal total amount of O2 delivery?
1000 mL of O2 per minute
Oxygen delivery decreases when there is a decline in what 3 things?
1)blood oxygenation 2)hemoglobin concentration 3)cardiac output
What is the normal oxygen content difference between arterial and venous blood?
5 vol%
Normal CaO2 is_________. Normal CvO2 is_________.
20 vol%; 15 vol%
The amount of oxygen extracted by the peripheral tissues during the period of 1 minute
Oxygen Consumption
Normal O2 Consumption
250 mLO2/min
the amount of oxygen extracted by the peripheral tissues divided by the amount of O2 delivered to the peripheral cells
Oxygen extraction ratio
normal O2 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
Pulmonary Shunting
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
Anatomic Shunts
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
Venous Admixture
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
What are the four main types of hypoxia?
1)hypoxic 2) anemic 3)circulatory 4) histotoxic
an abnormally low arterial O2 tension
Low or inadequate O2 for cellular metabolism
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
Histotoxic Hypoxia
What may appear whenever the blood contains at least 5 g% of reduced hemoglobin?
What is an increased level of RBCs?