Final answer:
The student nurse's statement that accessory muscles are routinely used to breathe indicates a misunderstanding. Age-related changes in breathing typically involve a decline in muscle strength, altered respiratory control, and thoracic rigidity, not habitual use of accessory muscles for normal breathing.
Step-by-step explanation:
The statement made by the student nurse that indicates a need for further teaching is: "Accessory muscles are used to breathe." While it is true that accessory muscles can be used to aid in respiration, particularly in cases of respiratory distress or high physical demand, the routine use of accessory muscles in normal, age-related changes of breathing is not typical. As individuals age, respiratory muscles may weaken, and the rigidity of the thoracic structures can increase, but the primary muscles of respiration remain the diaphragm and the intercostal muscles
With aging, the chest wall becomes stiffer and the lung tissue loses some of its elasticity, causing the V/Q ratio to potentially decrease. This ratio represents the matching of ventilation (airflow) and perfusion (blood flow) in the lungs. When there is a mismatch due to changes in compliance or resistance, as in the case of lung diseases like fibrosis, asthma, or emphysema, gas exchange efficiency is impaired. Chronic exposure to factors like high altitude can also affect respiratory function, as the body compensates over time with an increase in erythrocyte production to enhance oxygen delivery to tissues.