Spinal Cord

Spinal Cord
Golgi Tendon Organs
Encapsulated sensory receptors.
Located in tendons near their junction with the muscle.
10-15 muscle fibers are connected in series with each Golgi tendon organ.
Endings of afferent nerve fibers wrapped around collagen bundles in tendon

Contraction of attached extrafusal muscle fibers ? pull on the tendon ? straightens collagen bundles ? distorts receptor endings ? activating their afferent neurons
Transmission of APs to CNS via type Ib nerve fibers.
Inhibit via interneurons, of motor neurons to contracting muscle and its synergists.
Stimulate motor neurons of antagonistic muscles

Importance
Prevent muscle tearing or tendon avulsion from its attachments to the bone.
Equalize contractile forces of separate muscle fibers (fibers which exert excess tension become inhibited by the reflex ? spread muscle load over all fibers ? prevent damage in isolated areas of a muscle where small numbers of fibers might be overl

Polysynaptic Reflexes

Withdrawal reflex
Crossed-extensor reflex.
Abdominal reflex
Cremasteric reflex