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.
deep tendon reflex. n. Tonic contraction of the muscles in response to a stretching force, due to stimulation of muscle proprioceptors. deep tendon reflex (DTR) a brisk contraction of a muscle in response to a sudden stretch induced by a sharp tap by a finger or rubber hammer on the tendon of insertion of the muscle. Absence of the reflex may be caused by damage to the muscle, peripheral nerve, nerve roots, or spinal cord at that level.