1.
Protein synthesis: All of the following proteins are synthesized in the liver except:
Correct Answer
D. Factor VIII and vWF
Explanation
Factor VIII and vWF are not synthesized in the liver. Factor VIII is produced in endothelial cells and megakaryocytes, while vWF is synthesized in endothelial cells and megakaryocytes as well as in platelets. The liver is responsible for the synthesis of many proteins, including albumin, pseudocholinesterase, urea, and most coagulation factors, but not Factor VIII and vWF.
2.
Protein synthesis: Urea is formed in the liver by combing two molecules of _________ with CO2.
Correct Answer
ammonia
Explanation
Is then excreted by the kidneys
3.
Protein synthesis: In liver disease with decreased protein synthesis, protein-bound drugs will have a lesser clinical effect than in a healthy individual.
Correct Answer
B. False
Explanation
More drug will be available for the target organ, creating a greater effect
4.
Drug metabolism/transformation: Phase II reaction conjugates the product of phase I with a subsequent molecule such as glucoronide, sulfate, taurine, or glycine. Products of phase II have a larger molecular weight and are ionized, making them more _______ soluble, facilitating excreting and decreasing pharmacologic activity.
Correct Answer
water
H2O
Explanation
Phase II reactions in drug metabolism involve the conjugation of the product of phase I reactions with a subsequent molecule such as glucuronide, sulfate, taurine, or glycine. This conjugation results in the formation of larger molecules with increased molecular weight. These conjugates are also ionized, which makes them more water-soluble. The increased water solubility facilitates their excretion from the body, reducing their pharmacologic activity. Therefore, the correct answer is water (H2O).
5.
Drug metabolism/biotransformation: P-450 enzyme activity is _________ by a number of drugs including alcohol, phenytoin, and barbiturates. This is called enzyme induction, meaning that an apparent tolerance develops due to the rapid metabolism of drugs by P-450.
Correct Answer
A. Increased
Explanation
P-450 enzyme activity is increased by a number of drugs including alcohol, phenytoin, and barbiturates. This means that these drugs can enhance the activity of P-450 enzymes, leading to a more rapid metabolism of other drugs in the body. As a result, there may be a decrease in the effectiveness and duration of action of these drugs, leading to the development of apparent tolerance.
6.
Drug metabolism/Biotransformation: Which phase adds or exposes a functional group via oxidation, reduction, deamination, or other processes involving cytochrome P-450 enzymes?
Correct Answer
A. Phase I
Explanation
The end products, besides active metabolites, become water soluble that are excreted in bile or urine. This reaction typically results in loss of pharmacologic activity.
7.
Hepatic blood flow: The liver receives approximately 1.5 L/min of blood flow, which is ___% of cardiac output?
Correct Answer
B. 25
Explanation
The liver receives approximately 1.5 L/min of blood flow, which is 25% of cardiac output. This means that out of the total amount of blood pumped by the heart per minute, 25% of it goes to the liver. The liver plays a crucial role in filtering and processing blood, so it requires a significant amount of blood flow to carry out its functions effectively.
8.
Hepatic blood flow: The liver can compensate up to 25% of total blood volume during acute hemorrhage by expelling blood immediately from capacitance vessels.
Correct Answer
A. True
Explanation
Conversely, when vascular volume is acutely increased, as when fluids are rapidly infused, the hepatic blood volume expands, providing a buffer against acute increases in systemic blood volume.
9.
Hepatic blood flow: There are alpha and beta receptors in the hepatic artery but only _____ receptors in the portal vein.
Correct Answer
alpha
Explanation
The explanation for the correct answer "alpha" is that there are both alpha and beta receptors present in the hepatic artery, which is responsible for supplying oxygenated blood to the liver. However, in the portal vein, which carries nutrient-rich blood from the digestive system to the liver, only alpha receptors are present. This difference in receptor distribution suggests that the hepatic artery may be involved in regulating blood flow and vasoconstriction in the liver, while the portal vein may have a different role in the regulation of hepatic blood flow.
10.
Hepatic blood flow: A decrease/increase in either arterial or venous circulation is met by a compensatory increase/decrease in blood flow from the other system. This is called the hepatic artery buffer response (HABR) system, which allows the arterial/venous flow to change but not change overall total hepatic blood flow.
Correct Answer
A. True
Explanation
The explanation for the correct answer is that the hepatic artery buffer response (HABR) system allows for compensation in hepatic blood flow. If there is a decrease or increase in either arterial or venous circulation, the HABR system will respond by increasing or decreasing blood flow from the other system. This allows for changes in arterial or venous flow without affecting the overall total hepatic blood flow. Therefore, the statement is true.
11.
GFR: Renal blood flow is approximately 650 mL/min (20%-25% of cardiac output) - what percentage of this blood flow becomes filtrate?
Correct Answer
20
Explanation
Approximately 20% of the renal blood flow becomes filtrate. This means that out of the total blood flow of 650 mL/min, 130 mL/min (20% of 650 mL/min) is filtered by the kidneys.
12.
GFR: The glomerular _____ pressure is a high pressure (60 mmhg) exerted against the walls of the glomelular capillaries, it is the primary determinant of the amount of filtration occurring.
Correct Answer
hydrostatic
Explanation
The correct answer is "hydrostatic." In the context of the glomerular filtration rate (GFR), the hydrostatic pressure refers to the pressure exerted by the fluid in the glomerular capillaries against their walls. This pressure is high, around 60 mmHg, and it plays a crucial role in determining the amount of filtration that occurs.
13.
GFR: The glomerular capillary lining is made up of pores that are __________ charged.
Correct Answer
B. Negatively
Explanation
The glomerular capillary lining is made up of pores that are negatively charged. This negative charge helps to repel negatively charged particles, such as proteins and red blood cells, from passing through the pores and into the urine. This selective filtration allows for the passage of smaller molecules, such as water, electrolytes, and waste products, while preventing the loss of important proteins and blood cells.
14.
GFR: Which of the following will not become filtrate?
Correct Answer(s)
C. Albumin
D. RBC
Explanation
Albumin and RBCs are not normally found in the filtrate during the process of glomerular filtration. The glomerulus in the kidney acts as a filter that allows small molecules like Na+, glucose, amino acids, urea, and creatinine to pass through into the filtrate, while larger molecules like albumin and RBCs are too big to pass through and are therefore not present in the filtrate.
15.
GFR: Juxtaglomerular cells are smooth muscle cells in the arterioles that are sensitive to stretch – when they sense decreased renal blood flow they release renin in an attempt to maintain renal blood flow and GFR.
Correct Answer
A. True
Explanation
Juxtaglomerular cells are smooth muscle cells located in the arterioles of the kidney. These cells are sensitive to stretch and can detect a decrease in renal blood flow. When they sense this decrease, they release a hormone called renin. The release of renin is an attempt to maintain renal blood flow and glomerular filtration rate (GFR). Therefore, the statement that juxtaglomerular cells release renin to maintain renal blood flow and GFR is true.