the pathway through which messages (impluses) travel in bringing about knee-jerk when the tendon is tapped receptors in the muscle arestreached and this causes the message to be sent off. which structure is the receptor?
2006-09-12 03:26:19 · 3 answers · asked by jess_1991@btinternet.com 1 in Science & Mathematics ➔ Biology
When the tendon is stretched, it pulls on the muscle. In the muscle is the muscle spindle, which acts as a stretch receptor and sends action potentials to the spinal cord via neurons. These neurons synapse with alpha motor neurons (the neurons that carry instructions for movement) which will cause the muscle to contract causing a slight kick. Notice that this sensory/ motor pathway didn't involve the brain. Hence the knee-jerk reflex is a spinal cord reflex.
2006-09-12 05:54:06 · answer #1 · answered by kbit03 2 · 1⤊ 0⤋
it's the muscles
2006-09-14 01:56:41 · answer #2 · answered by Anonymous · 0⤊ 0⤋
This may help
http://www.ifisiol.unam.mx/Brain/reflex.htm
2006-09-12 03:42:50 · answer #3 · answered by starla_o0 4 · 0⤊ 0⤋