The USDA created the food pyramid to encourage a healthy diet, but the USDA also has a mission to encourage agricultural products grown in the US. There can be a LOT of conflict between those two goals. So the food pyramid (ahem, I mean MyPlate) is not simply an objective summary of the available evidence.
The stretch reflex (myotatic reflex) is a muscle contraction in response to stretching within the muscle. It is a monosynaptic reflex which provides automatic regulation of skeletal muscle length. When a muscle lengthens, the muscle spindle is stretched and its nerve activity increases.
The optokinetic reflex (nystagmus; OKN) is an involuntary fixation on objects that are moving in relationship to the head. This is classically observed when looking out of the side of a moving vehicle and has been termed railway nystagmus.