CHT Anatomy & Physiology Fundamentals 2 — Questions and Answers
Question 1: Which cellular organelle is primarily responsible for aerobic ATP production and is most directly affected by oxygen availability in hyperbaric therapy?
- Golgi apparatus
- Mitochondria (Correct answer)
- Endoplasmic reticulum
- Lysosome
Correct answer: Mitochondria
Mitochondria perform oxidative phosphorylation to produce ATP, a process that depends on adequate oxygen supply.
Question 2: The blood-brain barrier is primarily formed by which cell type surrounding cerebral capillaries?
- Microglia
- Oligodendrocytes
- Astrocytes (Correct answer)
- Schwann cells
Correct answer: Astrocytes
Astrocyte end-feet wrap around cerebral capillaries and contribute to tight junction formation, creating the blood-brain barrier.
Question 3: During hyperbaric oxygen therapy, oxygen delivery to tissues is enhanced because dissolved plasma oxygen bypasses which normal physiological limiting factor?
- Cardiac output
- Hemoglobin oxygen-carrying capacity (Correct answer)
- Venous return
- Pulmonary diffusion capacity
Correct answer: Hemoglobin oxygen-carrying capacity
HBOT increases dissolved plasma O₂ so tissue oxygenation continues even when hemoglobin is saturated or unavailable (e.g., CO poisoning, anemia).
Question 4: Which anatomical structure separates the right and left ventricles and, if defective, can cause paradoxical gas embolism in hyperbaric patients?
- Interatrial septum
- Interventricular septum
- Patent foramen ovale (Correct answer)
- Tricuspid valve
Correct answer: Patent foramen ovale
A patent foramen ovale (PFO) allows venous gas emboli to cross directly into arterial circulation, causing paradoxical arterial gas embolism.
Question 5: The Hering-Breuer reflex, which prevents lung over-inflation, is mediated by stretch receptors located in which structure?
- Aortic arch
- Carotid bodies
- Bronchial smooth muscle and lung parenchyma (Correct answer)
- Diaphragm muscle fibers
Correct answer: Bronchial smooth muscle and lung parenchyma
Pulmonary stretch receptors in the airways and lung parenchyma send inhibitory signals via the vagus nerve to stop inspiration when lungs are sufficiently inflated.
Question 6: In the context of oxygen toxicity, which tissue site is most vulnerable to CNS oxygen toxicity during hyperbaric exposure at pressures above 2.0 ATA?
- Cerebral cortex neurons (Correct answer)
- Peripheral nerve axons
- Cerebellar Purkinje cells
- Hippocampal dentate gyrus
Correct answer: Cerebral cortex neurons
Cortical neurons are highly sensitive to superoxide and hydroxyl radical formation under hyperoxia, predisposing to CNS O₂ toxicity seizures.
Question 7: The functional residual capacity (FRC) of the lungs represents which combination of lung volumes?
- Tidal volume + inspiratory reserve volume
- Expiratory reserve volume + residual volume (Correct answer)
- Vital capacity + residual volume
- Inspiratory capacity + tidal volume
Correct answer: Expiratory reserve volume + residual volume
FRC is the volume remaining in the lungs after a normal passive exhalation, comprising expiratory reserve volume plus residual volume.
CHT Anatomy & Physiology Fundamentals 2
Which cellular organelle is primarily responsible for aerobic ATP production and is most directly affected by oxygen availability in hyperbaric therapy?