Nokea
The impulse for voluntary muscles for forced breathing starts in
Correct Answer: A
Rationale: The correct answer is A: Medulla (pons). The medulla, located in the brainstem, controls involuntary functions like breathing. Specifically, the medulla contains the respiratory center, which regulates breathing rhythm and depth. During forced breathing, the medulla sends impulses to the voluntary muscles involved in breathing, such as the diaphragm and intercostal muscles. The pons, which is closely connected to the medulla, assists in regulating breathing patterns. The vagus nerve (B) is responsible for parasympathetic functions, not voluntary breathing. The cerebral hemispheres (C) are primarily involved in higher brain functions, not breathing regulation. The spinal cord (D) plays a role in transmitting signals between the brain and muscles but does not initiate voluntary breathing impulses.