How does a cervical spinal cord injury typically affect respiratory function?

• A. Normal respiratory rates with increased loudness
• B. Reduced lung volumes and muscle strength
• C. Increased lung capacity with high volume breaths
• D. No effect on respiratory function

Answer: (B)

A cervical spinal cord injury commonly results in weakened or impaired control of the respiratory muscles, particularly the diaphragm, which is primarily innervated by the phrenic nerve originating from the cervical spine. This impairment leads to reduced lung volumes because the muscles needed for inhalation and exhalation may not function properly or at full strength. As a result, individuals may experience shallow breathing, difficulty clearing secretions, and overall reduced capacity for effective ventilation.

In contrast, the other options do not align with the physiological consequences of a cervical spinal cord injury. For instance, normal respiratory rates with increased loudness would suggest that respiratory function is intact and possibly enhanced, which is not the case. Similarly, increased lung capacity would imply effective respiratory mechanics, a scenario unlikely post-injury. Finally, the idea that there would be no effect on respiratory function contradicts the reality that cervical spinal cord injuries typically lead to significant respiratory challenges due to compromised muscular control. Thus, the option indicating reduced lung volumes and muscle strength accurately reflects the impact of such injuries on respiratory function.