Cremo review Flashcards
The range of [H+] that corresponds to a normal blood pH is
35-45 nM
In an unopened bottle of soda water, the partial pressure of the gas above the liquid is
The same as in the liquid
An acidemic patient with normal lung and kidney function would most likely have recently experienced which of the following?
[HCO3-] will increase
When a sample of whole blood is exposed to an increased PCO2, what happens?
[HCO3-] and [H+] will increase
What is the relative concentration of O2 (in mm Hg) in dry air in Reno?
0.21·680 = 143mmHg
Which of the following has the highest PCO2 in the normal human?
Venous blood
When a sample of whole blood is exposed to an decreased PCO2, what will occur?
pH will increase
Which set of values best represent PCO2 levels related to human physiology?
Inspired air: expired air: alveolar air: venous blood: arterial blood
clinically zero: 4%; 1.2 mM; 1.35 mM; 1.2 mM
You can calculate the pH in plasma by plugging in measured values of PaCO2 and [HCO3-] using the Henderson equation. Do you have to account for other buffers present in the plasma to get the correct result for pH?
No, if the values I have measured are correct, the pH will be exactly what the equation says it will be
Bicarbonate is added to the blood by acid-producing cells in the stomach in response to a meal. Which best describes the buffering reaction that would mitigate pH changes due to the added bicarbonate?
HbH+ + HCO3 - →Hb + H2CO3 →Hb + CO2 + H2O
Which is the buffer system with the highest capacity to mitigate pH changes in the blood due to endogenous acid production?
Bicarbonate system because it is in the highest concentration and is an open system
Which of the following has the lowest PCO2 in the normal human?
Inspired air
You have a patient who is hypoxemic, but has a normal P(A-a)O2. What could be said about this patient?
They are either hypoventilating or they are experiencing a low PIO2
In pure emphysema, the lung is defined by areas of greatly enlarged air spaces with disruption of alveolar walls. What happens to the V/Q ratio?
High V/Q ratio
In pure bronchitis, there is abundant mucous secretions in the bronchial tree and narrowing of small airways due to inflammation and wall edema. What happens to the V/Q ratio?
Low V/Q ratio
In a lung with an embolism blocking the main artery, what will increase: physiologic dead space, regions with low V/Q, regions with high V/Q?
All of the above
An individual alveolus in a state of atelectasis…
has essentially ZERO ventilation
A patient with a normal pCO2 but a high p(A-a)O2 difference may have
asthma
Four basic mechanisms of hypoxemia
- a decrease in PIO2
- pure hypoventilation
- anatomic shunt
- V/Q mismatch
What is the hallmark of hypoventilation as a cause of hypoxia?
Elevated PaCO2
In a normal lung, is the V/Q ratio usually greater than or less than one?
A bit less than one
Alveolar gas exchange equation
PAO2 = %O2(Pb-47) - 1.2*PaCO2
Which protein has the most iron bound to it on a mol iron/mol protein basis?
Ferritin in the tissues
Which proteins are involved in the uptake of iron from the gut lumen into the plasma?
Ferroprotin
DMT1
Hephaestin
Ferric reductase
You have a patient with hemochromatosis. What symptoms might you observe?
Elevation in serum ferritin levels.
Hemosiderin in the parenchymal cells of the liver.
The aggregated form of ferritin often seen in patients with iron overload is called:
hemosiderin
erythropoiesis is stimulated by:
hypoxia
What is the rate limiting step during the biosynthesis of heme?
ALA synthase
The color of a healing bruise goes from reddish-purple to green to yellow. This color sequence is due to the conversion of:
localized heme to biliverdin to bilirubin
What kinds of things can cause conjugated hyperbilirubinemia?
Biliary tree inflammation
Common bile duct obstruction
Hepatitis
What catalyzes the rate liming step in heme catabolism?
Heme oxygenase
Regulation of heme synthesis depends upon the isoform of this enzyme:
delta-ALA synthase
T/F: Men can donate more blood than women without risking iron deficiency?
True
Two major sites of heme synthesis:
hepatocytes
developing RBCs
Where is erythropoietin produced?
Kidneys
What is the most likely cause of jaundice in a newborn infant?
Low glucuronidyl transferase activity
The major site of storage of iron in the body
liver parenchymal cell
Are the processes where iron is normally lost from the body on a daily basis regulated?
No
What does hepcidin do?
Inhibits the processes that put iron into the blood
How might an iron deficiency appear clinically?
Low serum ferritin
A jaundiced patient has normal indirect bilirubin but elevated direct bilirubin. Why might this be?
Obstructed gall bladder
Important enzyme that is involved in the mechanism to sense the concentration of O2 in a cell
Prolyl hydroxylase
