True
the muscle spindle detects excessive stretch within the muscle , it response and makes the muscle contract
True.
The Golgi tendon organ senses changes in muscle tension and helps protect muscles from excessive force by inhibiting muscle contraction. The muscle spindle detects changes in muscle length and contributes to muscle stretch reflexes and coordination of movement.
Muscle Spindle
the muscle spindle detects it, and causes reflexes that automatically make slight alterations to muscle tentions, so that you stand up right.
a muscle strain
the striated portions of the intrafusal fiber contract to keep the spindle taut at different muscle lengths. If the whole muscle is stretched, the muscle spindle is also stretched, triggering sensory nerve impulses on its nerve fiber. These sensory fibers synapse in the spinal chord with lower motor neurons leading back to the same muscle. Impulses triggered by stretch of the muscle spindle contract the skeletal muscle.
Muscle Spindle and Golgi Tendon Organ
Overstretching of a muscle initiates a stretch reflex spasm where the muscle spindle cells relay a message to the spinal cord, and an efferent message is sent to motor units to contract the muscle, thereby causing a muscle spasm.
A muscle spindle tightens when the muscle is stretched too far too fast to prevent damage to the muscle.
You can increase the muscle spindle reflection by exercising and taking lots of proteins.
Muscle spindle receptors which are located in the belly's of muscles measure length of stretch and speed of change. They send this afferent neural information to the posterior horn of the spinal cord where and interneuron interprets the information and if the stretch is ballistic (if it changes length too rapidly) it will trigger an efferent motor unit, or many motor units, through the anterior horn of the spinal cord to contract the muscle.