A lesion of ventrolateral pa of spinal cord will lead to loss of which of the following sensation below the level of lesion?
**Core Concept**
A lesion of the ventrolateral part of the spinal cord affects the spinothalamic tract, which is responsible for transmitting pain, temperature, and crude touch sensations from the body to the brain.
**Why the Correct Answer is Right**
The spinothalamic tract is a crucial component of the anterolateral system, which conveys painful and temperature sensations from the body to the thalamus. A lesion in the ventrolateral part of the spinal cord disrupts this pathway, resulting in the loss of pain and temperature sensation below the level of the lesion. This is because the spinothalamic tract crosses at the level of entry in the spinal cord, so a lesion in the ventrolateral part of the spinal cord will affect the contralateral side of the body.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because the dorsal column-medial lemniscus pathway, which includes the fasciculus gracilis and fasciculus cuneatus, is responsible for transmitting proprioception, vibration, and fine touch sensations, not pain and temperature sensations.
* **Option B:** This option is incorrect because the corticospinal tract, which controls voluntary motor function, is located in the lateral and anterior parts of the spinal cord, but a lesion in the ventrolateral part of the spinal cord will not affect motor function.
* **Option C:** This option is incorrect because the sympathetic nervous system, which is responsible for the "fight or flight" response, is located in the lateral and anterior parts of the spinal cord, but a lesion in the ventrolateral part of the spinal cord will not affect sympathetic function.
**Clinical Pearl / High-Yield Fact**
A mnemonic to remember the sensations affected by a lesion in the ventrolateral part of the spinal cord is "Pain and Temperature, Proprioception and Positioning are Protected": P and T are affected, while P and P are not.
**Correct Answer: C. Pain and temperature sensation.**