Which of these events does NOT occur during ventricular diastole?
Atrial contraction
Ventricular ejection
✓
Ventricular filling
Isovolumetric relaxation
Correct Answer
Ventricular ejection
Isovolumetric relaxation, ventricular filling, and atrial contraction all occur during ventricular diastole. Ventricular ejection occurs during ventricular systole.
Question 2
Which of these is NOT an atrioventricular (AV) valve?
Mitral valve
Aortic valve
✓
Bicuspid valve
Tricuspid valve
Correct Answer
Aortic valve
The mitral (bicuspid) valve and tricuspid valve are atrioventricular (AV) valves. The aortic valve is a semilunar valve.
Question 3
Three of these conditions decrease hemoglobin's affinity for oxygen. Which one does not?
Increased CO2
Increased temperature
Decreased 2,3-BPG
✓
Decreased pH
Correct Answer
Decreased 2,3-BPG
Increased CO2 (Bohr effect), decreased pH (Bohr effect), and increased temperature all decrease hemoglobin's affinity for oxygen. Decreased 2,3-BPG increases hemoglobin's affinity for oxygen.
Question 4
Which of these muscles is NOT primarily involved in quiet inspiration?
Diaphragm
Scalenes
External intercostals
Internal intercostals
✓
Correct Answer
Internal intercostals
The diaphragm and external intercostals are primarily involved in quiet inspiration. Internal intercostals are primarily involved in forced expiration. Scalenes are accessory muscles for forced inspiration.
Question 5
Which of these is not a component of the juxtaglomerular apparatus (JGA)?
Podocytes
✓
Extraglomerular mesangial cells
Granular cells
Macula densa
Correct Answer
Podocytes
The macula densa, granular cells (juxtaglomerular cells), and extraglomerular mesangial cells are components of the juxtaglomerular apparatus. Podocytes are part of the glomerular filtration barrier.
Question 6
Which of these substances is not reabsorbed in the collecting duct?
Urea
Water
Glucose
✓
Sodium
Correct Answer
Glucose
Under the influence of ADH, the collecting duct primarily reabsorbs water. Sodium and urea reabsorption also occur here, but glucose is normally 100% reabsorbed in the proximal convoluted tubule.
Question 7
Which of these is NOT a characteristic feature of an action potential?
Decremental conduction
✓
Has a threshold
All-or-none event
Self-propagating
Correct Answer
Decremental conduction
Action potentials are all-or-none, self-propagating, and have a threshold. Decremental conduction, where the signal strength decreases over distance, is characteristic of graded potentials.
Question 8
Which of these neurotransmitters is not a catecholamine?
Epinephrine
Acetylcholine
✓
Dopamine
Norepinephrine
Correct Answer
Acetylcholine
Dopamine, norepinephrine, and epinephrine are all catecholamine neurotransmitters, derived from tyrosine. Acetylcholine is a separate class of neurotransmitter.
Question 9
Which of these hormones is not released by the anterior pituitary?
Thyroid-stimulating hormone (TSH)
Follicle-stimulating hormone (FSH)
Prolactin
Oxytocin
✓
Correct Answer
Oxytocin
Prolactin, TSH, and FSH are hormones released by the anterior pituitary gland. Oxytocin is synthesized in the hypothalamus and released from the posterior pituitary gland.
Question 10
Which of these is not a steroid hormone?
Cortisol
Estrogen
Insulin
✓
Aldosterone
Correct Answer
Insulin
Cortisol, aldosterone, and estrogen are all steroid hormones, derived from cholesterol. Insulin is a peptide hormone.
Question 11
Which of these is NOT a variable typically maintained near a set point by homeostatic mechanisms?
Blood glucose
Blood pH
Hair color
✓
Body temperature
Correct Answer
Hair color
Body temperature, blood glucose, and blood pH are physiological variables actively regulated by homeostatic mechanisms to maintain them within a narrow range. Hair color is a genetic trait and not a homeostatically regulated variable.
Question 12
Which of these is NOT typically an effector in a homeostatic feedback loop?
Gland
Muscle
Adipose tissue
Sensory neuron
✓
Correct Answer
Sensory neuron
Muscles, glands, and adipose tissue can all act as effectors, carrying out responses to restore homeostasis. A sensory neuron acts as a receptor or part of the afferent pathway, detecting changes, not executing a response.
Question 13
Which of these statements about the QRS complex on an ECG is FALSE?
Precedes ventricular contraction
Represents atrial repolarization
✓
Represents ventricular depolarization
Is typically the largest wave
Correct Answer
Represents atrial repolarization
The QRS complex represents ventricular depolarization, is typically the largest wave, and precedes ventricular contraction. Atrial repolarization also occurs during this time but is electrically masked by the larger ventricular depolarization.
Question 14
Three of these factors increase the rate of oxygen diffusion at the alveoli. Which one does not?
Increased thickness of respiratory membrane
✓
Increased partial pressure gradient for O2
Increased alveolar surface area
Increased temperature of blood
Correct Answer
Increased thickness of respiratory membrane
Increased alveolar surface area and an increased partial pressure gradient for O2 would increase diffusion. Increased thickness of the respiratory membrane and increased blood temperature (which decreases O2 affinity for Hb, making it harder to load) would decrease the rate of oxygen diffusion.
Question 15
Which of these processes does NOT primarily occur in the renal corpuscle?
Reabsorption
✓
Filtration
Hydrostatic pressure driven fluid movement
Formation of ultrafiltrate
Correct Answer
Reabsorption
Filtration, formation of ultrafiltrate, and hydrostatic pressure driven fluid movement are all primary processes occurring in the renal corpuscle. Reabsorption is the primary process occurring in the renal tubules.