Question

Which of the following statements accurately describes the phrenic nerve?

Options:

A) The phrenic nerve arises from the lumbar plexus.
B) The phrenic nerve supplies motor fibers to the heart.
C) The phrenic nerve supplies both motor and sensory fibers to the diaphragm, the main breathing muscle, and irritation of the phrenic nerve can cause hiccups.
D) Severing both phrenic nerves results in increased respiratory function.

Answer 1

The phrenic nerve supplies motor and sensory fibers to the diaphragm, arises from the cervical plexus, and is critical for diaphragmatic movement for breathing.

Step-by-step explanation:

The correct statement that accurately describes the phrenic nerve is option C) The phrenic nerve supplies both motor and sensory fibers to the diaphragm, the main breathing muscle, and irritation of the phrenic nerve can cause hiccups. The phrenic nerve arises from the cervical plexus, composed of axons from spinal nerves C1 through C5, and plays a crucial role in controlling diaphragmatic movement essential for breathing. Severing both phrenic nerves would not increase respiratory function; contrarily, it would lead to ventilatory failure as the diaphragm would be paralysed.

The phrenic nerve is not associated with the lumbar plexus nor does it provide motor fibers to the heart. Instead, it is directly involved with the involuntary action of breathing by stimulating the diaphragm. When irritated, such as by infections or other processes, it can cause hiccups due to involuntary contractions of the diaphragm.