Test Your Knowledge On Knee Reflex Test

Explanation
The knee jerk reflex test involves tapping the patellar tendon just below the kneecap, which causes the quadriceps muscle to contract and extend the leg. This reflex is mediated by the monosynaptic pathway involving the sensory neurons in the muscle spindle and motor neurons in the spinal cord. The sensory information from the patellar tendon travels through the femoral nerve, which arises from the lumbar plexus formed by the spinal nerves L2, L3, and L4. Therefore, all of these segments of the spinal cord are involved in the knee jerk reflex.

Explanation
The absence or decrease of knee-jerk reflex is known as Westphal's sign.

Explanation
The knee-jerk reflex is also known as the patellar reflex. This reflex occurs when the patellar tendon, located just below the kneecap, is tapped, causing the quadriceps muscle to contract and the lower leg to kick forward. This reflex is mediated by the spinal cord and does not involve the cerebellum. Therefore, the correct answer is Patellar reflex.

Explanation
The knee jerk reflex was first reported around 1875.

Explanation
The alpha motor neuron is responsible for the contraction of the legs during the knee reflex test. This type of motor neuron is located in the spinal cord and is responsible for activating skeletal muscles. When the knee is tapped, the sensory information is transmitted to the spinal cord, which then activates the alpha motor neuron to stimulate the contraction of the leg muscles, causing the reflexive movement of the leg.

Explanation
In his physiology textbook, Sir Michael Foster recorded the knee-jerk reflex in 1877.

Explanation
Multiple leg oscillations during the knee-jerk reflex can be a sign of cerebellar diseases. The knee-jerk reflex is controlled by the spinal cord and the cerebellum, which is responsible for coordinating movement and maintaining balance. When there are abnormalities or damage to the cerebellum, it can disrupt the normal reflex response and result in multiple leg oscillations. This is why cerebellar diseases, such as ataxia or cerebellar degeneration, can manifest as abnormal knee-jerk reflexes. Muscle diseases or dementia do not specifically affect the cerebellum and are not associated with this particular reflex abnormality.

Explanation
Both Wilhelm Heinrich Erb and Carl Friedrich Westphal are credited with reporting the knee-jerk reaction. Therefore, the correct answer is "Both (a) and (b)".

Explanation
In the knee-jerk reflex, tapping the tendon acts as the stimulus. A stimulus is any external event or action that triggers a response in an organism. In this case, the tapping of the tendon causes the sensory receptors in the muscle to send signals to the spinal cord, which then triggers the reflexive contraction of the muscle. Therefore, tapping the tendon serves as the stimulus that initiates the knee-jerk reflex.

Explanation
The knee-jerk reflex is an example of a monosynaptic reflex arc. In this reflex, the sensory neuron directly synapses with the motor neuron in the spinal cord, without involving any interneurons. When the patellar tendon is tapped, the stretch receptors in the muscle send signals to the spinal cord, which immediately triggers a motor response to contract the quadriceps muscle and extend the leg. This direct connection between the sensory and motor neurons allows for a quick and automatic response to a stimulus, making it an example of a monosynaptic reflex arc.