Final answer:
The skeletal muscles involved in producing the contractions related to inspiration are stimulated by motor impulses originating from the dorsal respiratory group (DRG) region of the medulla oblongata.
Step-by-step explanation:
The skeletal muscles involved in producing the contractions related to inspiration are stimulated by motor impulses originating from the dorsal respiratory group (DRG) region of the medulla oblongata.
When the DRG is active, it stimulates the contraction of the diaphragm and intercostal muscles, resulting in inspiration or the inhalation of air.
The DRG plays a crucial role in maintaining a constant breathing rhythm and can also stimulate the accessory muscles involved in forced breathing.