ABA Fundamentals & Core Concepts 2 — Questions and Answers
Question 1: Which receptor subtype mediates the analgesic effects of opioids at the spinal cord level?
- Delta (δ) receptor
- Kappa (κ) receptor
- Mu (μ) receptor (Correct answer)
- Sigma (σ) receptor
Correct answer: Mu (μ) receptor
Mu (μ) receptors are the primary mediators of spinal analgesia, respiratory depression, and euphoria produced by opioids.
Question 2: The Fick principle for cardiac output calculation requires measurement of which variables?
- Heart rate, stroke volume, and SVR
- Oxygen consumption, arterial O2 content, and venous O2 content (Correct answer)
- Blood pressure, heart rate, and pulmonary wedge pressure
- CVP, PAP, and pulmonary capillary wedge pressure
Correct answer: Oxygen consumption, arterial O2 content, and venous O2 content
The Fick principle states that cardiac output equals oxygen consumption divided by the arteriovenous oxygen content difference.
Question 3: Which property of local anesthetics determines their potency?
- pKa value
- Protein binding
- Lipid solubility (Correct answer)
- Molecular weight
Correct answer: Lipid solubility
Lipid solubility is the primary determinant of local anesthetic potency, as it determines membrane penetration and receptor binding affinity.
Question 4: During inhalation anesthesia, the blood:gas partition coefficient primarily determines:
- Potency of the anesthetic agent
- Speed of induction and recovery (Correct answer)
- Cardiovascular side effect profile
- Degree of metabolism in the liver
Correct answer: Speed of induction and recovery
A lower blood:gas partition coefficient means less agent must dissolve in blood before equilibrium with alveolar gas is achieved, resulting in faster induction and recovery.
Question 5: Which of the following best describes the mechanism of action of non-depolarizing neuromuscular blocking agents?
- Persistent activation of nicotinic acetylcholine receptors
- Competitive antagonism at the nicotinic acetylcholine receptor (Correct answer)
- Inhibition of acetylcholine synthesis in the nerve terminal
- Blockade of voltage-gated calcium channels at the NMJ
Correct answer: Competitive antagonism at the nicotinic acetylcholine receptor
Non-depolarizing NMBAs competitively block nicotinic acetylcholine receptors at the motor end plate without activating them.
Question 6: The oxygen-hemoglobin dissociation curve shifts to the RIGHT in the presence of:
- Decreased temperature and alkalosis
- Increased 2,3-DPG and acidosis (Correct answer)
- Decreased PCO2 and alkalosis
- Increased pH and decreased temperature
Correct answer: Increased 2,3-DPG and acidosis
Increased 2,3-DPG, acidosis (Bohr effect), hypercapnia, and elevated temperature shift the curve rightward, decreasing hemoglobin's oxygen affinity and facilitating O2 delivery to tissues.
Question 7: Which phase of hepatic drug metabolism involves conjugation reactions such as glucuronidation?
- Phase I reactions
- Phase II reactions (Correct answer)
- Phase III reactions
- Phase IV reactions
Correct answer: Phase II reactions
Phase II metabolism involves conjugation reactions (glucuronidation, sulfation, acetylation) that typically increase drug water solubility for renal excretion.
ABA Fundamentals & Core Concepts 2
Which receptor subtype mediates the analgesic effects of opioids at the spinal cord level?