This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
Which among the following is detected by muscle spindle? 
Select and explain. 
A. Tension, B. Length, C. Proprioception, D. Stretch
B: Length
Answer: B: Length 
Explanation: Muscle spindle primarily detect changes in the length of this muscle. They convey length information to the central nervous system sensory neurons. This information can be processed by the brain to determine the position of body pas. The responses of muscle spindles to changes in length also play an impoant role in regulating the contraction of muscles, by activating motoneurons the stretch reflex to resist muscle stretch. Golgi tendon detects muscle tension and rate of change of muscle tension. Ref: Barrett K.E., Barman S.M., Boitano S., Brooks H.L. (2012). Chapter 12. Reflex and Voluntary Control of Posture & Movement. In K.E. Barrett, S.M. Barman, S. Boitano, H.L. Brooks (Eds), Ganong's Review of Medical Physiology, 24e