Question

which of the following statements is true regarding the stretch reflex?multiple choicenone are true.relative to the muscle spindles being stretched, it involves excitation of contralateral motor neurons.it reduces the force the ipsilateral muscles produce during contraction.it resists changes in muscle length.it involves afferent activity from muscle spindles whose axons travel up the spinal cord in the anterolateral columns.

Answer 1

The true statement about the stretch reflex is that it resists changes in muscle length by causing the muscle to contract when muscle spindles are activated.

Step-by-step explanation:

The student asked which statement is true regarding the stretch reflex. The correct answer to this question is that the reflex resists changes in muscle length. Specifically, when a skeletal muscle is stretched, muscle spindles are activated and send signals through afferent neurons to the spinal cord. These neurons then synapse directly on motor neurons in the ventral horn, which causes the muscle to contract, countering the stretch. This mechanism helps maintain a constant muscle length. Additionally, the process involves the inhibition of motor neurons of the antagonist muscles, thus providing stability and coordination.

Answer 2

The true statement is that the stretch reflex resists changes in muscle length by causing muscle contraction in response to stretching, which is detected by muscle spindle receptors.

Step-by-step explanation:

The statement that is true regarding the stretch reflex is that it resists changes in muscle length. When a skeletal muscle is stretched, the reflex is initiated by the activation of a muscle spindle receptor, a type of stretch receptor located within the muscle. This triggers an afferent signal to the spinal cord, leading to the excitation of motor neurons that cause the stretched muscle to contract. Concurrently, the antagonistic muscles are inhibited, a process that ensures muscle balance and prevents overstretching.

In neurological exams, a common manifestation of the stretch reflex is the knee response when a doctor taps the patellar ligament with a rubber hammer. This quick stretch leads to the activation of muscle spindles, which subsequently causes the quadriceps muscle to contract, helping the body maintain stability and posture.