Respiratory System — Flashcards

Flashcard 121: Smoking causes _____ to the sensitivity of the chemoreceptors.

Answer: no change (change/no change)

Flashcard 122: Work done in quiet breathing is _____ kg-m/min

Answer: 0.5

Flashcard 123: Type _____, also called as periop. respiratory failure, is because of lung atelectasis

Answer: III

Flashcard 124: Hering-Breuer reflexes are mediated by _____ adapting pulmonary stretch receptors and the impulses travel in the vagus nerve via large myelinated fibers.

Answer: slowly (rapidly/slowly)

Flashcard 125: HFNC _____ the nasopharyngeal dead space

Answer: decreases

Flashcard 126: Both peripheral and central chemoreceptors contribute to increased ventilation that occurs as a result of decreased _____.

Answer: pH

Extra: Both peripheral and central chemoreceptors respond to a decrease in pH (acidosis) and an increase in PCO2 (hypercapnia). - **Peripheral chemoreceptors** (carotid and aortic bodies): Respond directly to a decrease in **arterial pH**, an increase in PCO2, and a decrease in PO2 (< 60 mmHg). - **Central chemoreceptors** (medulla): Respond to a decrease in the **pH of the CSF/brain extracellular fluid**. Since H+ cannot cross the blood-brain barrier, this is primarily driven by an increase in arterial PCO2 (which crosses easily and is converted to H+ and HCO3-). Note: Only peripheral chemoreceptors respond to changes in arterial pH (e.g., metabolic acidosis) and low PO2. Both respond to changes in PCO2.

Flashcard 127: The rate of inspiration is controlled by the _____ center.

Answer: pneumotaxic

Flashcard 128: The ventral respiratory group contributes to the extra respiratory drive (_____ mechanism)

Answer: overdrive

Flashcard 129: The primary function of the larynx is _____

Answer: to protect the airway

Flashcard 130: Most potent stimulus for central chemoreceptor in blood is _____ levels

Answer: CO2