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.
Cranial Nerves The human brain has 12 pairs of special nerves called the cranial nerves. These are specifically bundle of neurons and axons which transmit special information to and from the brain. They are generally very similar to spinal nerves in their make-up.