Principles of Pharmacology APEA Quiz answers
1. What is included in neuron structure?
neuron is composed of 3 basic parts. Soma, axon, and dendrites
2. What is the most common method by which drugs are chemically altered in the liver?
ANSEWR: OXDIATION
The primary location of drug metabolism is the liver. Metabolism is the process by which
drugs are chemically changed from a lipid-soluble form suitable for absorption and
distribution to a more water-soluble form that is suitable for excretion. The process
effectively eliminates the parent drug. Drug metabolism occurs in two phases. In phase
1, the drug molecules are altered chemically (by oxidation, reduction or hydrolysis) to
make them suitable for phase II reactions for excretion. Oxidation is the most common
form of Phase I reaction and chiefly involves members of the cytochrome P450 family of
membrane-bound enzymes in the smooth endoplasmic reticulum of the liver cells.
Oxidation is the loss of electrons or an increase in oxidation state by a molecule, atom,
or ion. Reduction is the gain of electrons or a decrease in oxidation state by a molecule,
atom or ion. Reduction is the gain of electrons or a decrease in oxidation state by a
molecule, atom or ion. Oxidation is responsible for the aging process in. the body. It is
also the most common form in which drugs are chemically altered within the smooth
endoplasmic reticulum of liver cells
3. In the pharmacokinetics of a drug, the rate of metabolism
Metabolism is the process by which drugs are changed from a lipid-soluble form suitable
for absorption and distribution to a more water-soluble form that is suitable for
excretion. The rate of drug metabolism varies widely among patients, influenced by
genetic and environmental factors. This is the major reason for differences in the plasma
concentration of some drugs after a standard dose, leading to a wide variation in drug
response.
4. Which of the following is a neurotransmitter within the parasympathetic nervous
system?
Acetylcholine is the neurotransmitter used at the neuromuscular junction and as the
final product released by the parasympathetic nervous system (“rest and digest”
system). Epinephrine, dopamine and norepinephrine are catecholamines that act to
stimulate the “fight or flight” system (sympathetic nervous system).
5. The first-pass effect contributes to oral bioavailability of a drug by:
ANSWER: Decreasing the amount of drug that is actually delivered into general
circulation after passing through the gastrointestinal system and the liver.
Explanation: After a drug is swallowed, it is absorbed by the digestive system and enters
the hepatic portal system. It is carried through the portal vein into the liver before it
reaches the rest of the body. The liver metabolizes many drugs, sometimes to an extent
that only a small amount of active drug emerges from the liver to the rest of the
, circulatory system. This first pass through the liver thus greatly reduces the
bioavailability of a drug.
6. A chemical synapse differs from an electrical synapse in that the signal transmission:
ANSWER: requires a neurotransmitter
Explanation: Electrical and chemical synapses occur within the nervous system. They
connect neurons together and transmit signals occurs neurons. Chemical synapses
required neurotransmitters to release signals. The space between the pre- and post-
synaptic ends are larger in chemical synapses than electrical. Unlike electrical synapses,
chemical synapses can only occur in ONE direction. Singla transmission with chemical
synapses is an active process that requires energy and only occurs at a moderate speed.
7. Electrical synapses differ from chemical synapse in that signal transmission:
ANSWER: Can occur in both directions
Explanation: Electrical and chemical synapses occur within the nervous system. They
connect neurons together and transmit signals across neurons. Electrical synapses transmit
electrical signals, rather than use, neurotransmitters. Signals sent by electrical synapses are
not modified during transmission. The electrical signal passes via gap junctions. The space
between the pre and postsynaptic ends is small, and the signal transmission can occur in
both directions. Signal transmission is fast. It is a passive process and does not require
energy.
8. If a 100-mg drug is administered and has a half-life of 6 hours, the percentage of the
drug that will be in the system 18 hours later is:
ANSWER: 12.5%
Explanation: The half-life of a drug refers to the time it takes for the plasma concentration of
the drug to be reduced to half of its original value. So a drug with a 6-hour half-life is at 50%
plasma concentration at hours, 25% at 12 hours, 12.5% at 18 hours, and 6.25% at 24 hours.
The half life is determined by the metabolism and excretion rate of the drug.
9. Therapeutic indices of a drug should be determined from a serum sample obtained
during:
ANSWER: at steady state of the drug
Explanation: blood samples are usually collected at steady state to obtain clinically
useful serum drug concentrations. When a fixed dose is administered at regular
intervals, a drug will accumulate in the body during the absorption phase until it reaches
a steady state, during which the rate of drug intake equals the rate of drug elimination.
The time required to reach steady state depends on the elimination half-life of the drug,
defined as the time required for the serum drug concentration to decrease by 50%. The
half-life itself determined by the metabolism and excretion rates of the drug. Under
conditions of first-order kinetics in a one-compartment distribution model (drug is
rapidly and evenly distributed throughout the body) and in the absence of a loading
dose, at least 5 half-lives are required to achieve a steady state.
1. What is included in neuron structure?
neuron is composed of 3 basic parts. Soma, axon, and dendrites
2. What is the most common method by which drugs are chemically altered in the liver?
ANSEWR: OXDIATION
The primary location of drug metabolism is the liver. Metabolism is the process by which
drugs are chemically changed from a lipid-soluble form suitable for absorption and
distribution to a more water-soluble form that is suitable for excretion. The process
effectively eliminates the parent drug. Drug metabolism occurs in two phases. In phase
1, the drug molecules are altered chemically (by oxidation, reduction or hydrolysis) to
make them suitable for phase II reactions for excretion. Oxidation is the most common
form of Phase I reaction and chiefly involves members of the cytochrome P450 family of
membrane-bound enzymes in the smooth endoplasmic reticulum of the liver cells.
Oxidation is the loss of electrons or an increase in oxidation state by a molecule, atom,
or ion. Reduction is the gain of electrons or a decrease in oxidation state by a molecule,
atom or ion. Reduction is the gain of electrons or a decrease in oxidation state by a
molecule, atom or ion. Oxidation is responsible for the aging process in. the body. It is
also the most common form in which drugs are chemically altered within the smooth
endoplasmic reticulum of liver cells
3. In the pharmacokinetics of a drug, the rate of metabolism
Metabolism is the process by which drugs are changed from a lipid-soluble form suitable
for absorption and distribution to a more water-soluble form that is suitable for
excretion. The rate of drug metabolism varies widely among patients, influenced by
genetic and environmental factors. This is the major reason for differences in the plasma
concentration of some drugs after a standard dose, leading to a wide variation in drug
response.
4. Which of the following is a neurotransmitter within the parasympathetic nervous
system?
Acetylcholine is the neurotransmitter used at the neuromuscular junction and as the
final product released by the parasympathetic nervous system (“rest and digest”
system). Epinephrine, dopamine and norepinephrine are catecholamines that act to
stimulate the “fight or flight” system (sympathetic nervous system).
5. The first-pass effect contributes to oral bioavailability of a drug by:
ANSWER: Decreasing the amount of drug that is actually delivered into general
circulation after passing through the gastrointestinal system and the liver.
Explanation: After a drug is swallowed, it is absorbed by the digestive system and enters
the hepatic portal system. It is carried through the portal vein into the liver before it
reaches the rest of the body. The liver metabolizes many drugs, sometimes to an extent
that only a small amount of active drug emerges from the liver to the rest of the
, circulatory system. This first pass through the liver thus greatly reduces the
bioavailability of a drug.
6. A chemical synapse differs from an electrical synapse in that the signal transmission:
ANSWER: requires a neurotransmitter
Explanation: Electrical and chemical synapses occur within the nervous system. They
connect neurons together and transmit signals occurs neurons. Chemical synapses
required neurotransmitters to release signals. The space between the pre- and post-
synaptic ends are larger in chemical synapses than electrical. Unlike electrical synapses,
chemical synapses can only occur in ONE direction. Singla transmission with chemical
synapses is an active process that requires energy and only occurs at a moderate speed.
7. Electrical synapses differ from chemical synapse in that signal transmission:
ANSWER: Can occur in both directions
Explanation: Electrical and chemical synapses occur within the nervous system. They
connect neurons together and transmit signals across neurons. Electrical synapses transmit
electrical signals, rather than use, neurotransmitters. Signals sent by electrical synapses are
not modified during transmission. The electrical signal passes via gap junctions. The space
between the pre and postsynaptic ends is small, and the signal transmission can occur in
both directions. Signal transmission is fast. It is a passive process and does not require
energy.
8. If a 100-mg drug is administered and has a half-life of 6 hours, the percentage of the
drug that will be in the system 18 hours later is:
ANSWER: 12.5%
Explanation: The half-life of a drug refers to the time it takes for the plasma concentration of
the drug to be reduced to half of its original value. So a drug with a 6-hour half-life is at 50%
plasma concentration at hours, 25% at 12 hours, 12.5% at 18 hours, and 6.25% at 24 hours.
The half life is determined by the metabolism and excretion rate of the drug.
9. Therapeutic indices of a drug should be determined from a serum sample obtained
during:
ANSWER: at steady state of the drug
Explanation: blood samples are usually collected at steady state to obtain clinically
useful serum drug concentrations. When a fixed dose is administered at regular
intervals, a drug will accumulate in the body during the absorption phase until it reaches
a steady state, during which the rate of drug intake equals the rate of drug elimination.
The time required to reach steady state depends on the elimination half-life of the drug,
defined as the time required for the serum drug concentration to decrease by 50%. The
half-life itself determined by the metabolism and excretion rates of the drug. Under
conditions of first-order kinetics in a one-compartment distribution model (drug is
rapidly and evenly distributed throughout the body) and in the absence of a loading
dose, at least 5 half-lives are required to achieve a steady state.
