While examining his knee jerk Suresh's doctor found that there was no response but Suresh informs that he could feel the tendon hammer touching his knee. Where is the problem likely to be ?

Options

A. Afferent pathway
B. Dorsal ganglion
C. Receptors
D. Efferent pathway

Answer

To solve the problem presented in the question regarding Suresh's knee jerk reflex, we can break down the situation step by step:

### Step-by-Step Solution:

1. **Understanding the Knee Jerk Reflex**:
- The knee jerk reflex is a simple reflex action that involves a sensory (afferent) neuron and a motor (efferent) neuron. When the patellar tendon is tapped, it stretches, and this stretch is detected by sensory receptors.

2. **Sensory Input**:
- In Suresh's case, he can feel the tendon hammer touching his knee. This indicates that the sensory receptors in his knee are functioning properly. The afferent neurons are transmitting the sensory information to the spinal cord.

3. **Reflex Arc Components**:
- The reflex arc consists of:
- Afferent neuron (sensory)
- Spinal cord (central processing)
- Efferent neuron (motor)
- Effector (muscle that responds)
- Since Suresh can feel the touch, the afferent pathway is intact.

4. **Absence of Motor Response**:
- The problem arises because Suresh does not exhibit a knee jerk response. This suggests that while the sensory information is being received, the motor signal is not being sent back to the muscle to initiate movement.

5. **Identifying the Problem**:
- Since the sensory pathway is functioning (Suresh feels the touch), the issue must lie in the efferent pathway. The motor neurons responsible for sending signals from the spinal cord to the knee muscles are likely damaged or not functioning properly.

6. **Conclusion**:
- Therefore, the most likely problem is in the efferent neuron or efferent pathway, which is responsible for transmitting the motor signal that would cause the knee to jerk.

### Final Answer:
The problem is likely to be in the **efferent neuron or efferent pathway**.