Which nerves supply the diaphragm?

Which nerves supply the diaphragm?

• A. Phrenic nerves.
• B. Intercostal nerves.
• C. Vagus nerves.
• D. Costal nerves.

Answer: (A)

The phrenic nerves are essential for the function of the diaphragm, as they provide the necessary motor innervation to this crucial respiratory muscle. Each phrenic nerve arises from the cervical spinal roots (C3, C4, and C5) and descends to the diaphragm, allowing it to contract and relax effectively during the process of inhalation and exhalation. This contraction of the diaphragm creates a negative pressure in the thoracic cavity, facilitating the inflow of air into the lungs. Other nerves mentioned do have roles in chest and respiratory functions, but they do not primarily control the diaphragm. Intercostal nerves primarily supply the intercostal muscles, which support the rib cage during breathing but do not directly innervate the diaphragm. The vagus nerves are involved in autonomic control of various thoracic and abdominal organs but are not responsible for motor control of the diaphragm. Costal nerves do not exist as recognized anatomical structures in the same way as phrenic, intercostal, and vagus nerves. Thus, the phrenic nerves are specifically tasked with activating the diaphragm, making them the correct response in this context.

The phrenic nerves are essential for the function of the diaphragm, as they provide the necessary motor innervation to this crucial respiratory muscle. Each phrenic nerve arises from the cervical spinal roots (C3, C4, and C5) and descends to the diaphragm, allowing it to contract and relax effectively during the process of inhalation and exhalation. This contraction of the diaphragm creates a negative pressure in the thoracic cavity, facilitating the inflow of air into the lungs.

Other nerves mentioned do have roles in chest and respiratory functions, but they do not primarily control the diaphragm. Intercostal nerves primarily supply the intercostal muscles, which support the rib cage during breathing but do not directly innervate the diaphragm. The vagus nerves are involved in autonomic control of various thoracic and abdominal organs but are not responsible for motor control of the diaphragm. Costal nerves do not exist as recognized anatomical structures in the same way as phrenic, intercostal, and vagus nerves. Thus, the phrenic nerves are specifically tasked with activating the diaphragm, making them the correct response in this context.