An inertial measurement unit works by detecting the current rate of acceleration using one or more accelerometers, and detects changes in rotational attributes like pitch, roll and yaw using one or more gyroscopes. And some also include a magnetometer, mostly to assist calibration against orientation drift.
In the human there are 31 pairs of spinal nerves, one on each side of the vertebral column. These are grouped into the corresponding cervical, thoracic, lumbar, sacral and coccygeal regions of the spine.
How Many Cranial Nerves Are There? Nerves arising directly from the brain are called cranial nerves, while those arising from the spinal cord are called peripheral nerves. These nerves pass from the brain through openings in the skull called foramina, to supply various parts of the head and neck, although some have extensions to the body.