Ablation of the “somatosensory area V of the cerebral cortex leads to:
**Core Concept:** The somatosensory area V of the cerebral cortex is responsible for processing tactile information from the upper limbs and face. It is located in the central sulcus on the pial surface of the cerebral hemisphere.
**Why the Correct Answer is Right:** Ablation of the somatosensory area V would disrupt the neural pathways involved in processing tactile information from these regions. This would lead to a loss of sensation in the corresponding body parts, as these neurons are responsible for transmitting sensory information from the upper limbs and face to the brain.
**Why Each Wrong Option is Incorrect:**
A. Option A (loss of motor function): Ablation of somatosensory area V should not lead to motor deficits as it is not involved in motor functions.
B. Option B (loss of vision): Ablation of somatosensory area V does not affect vision, as vision is processed in the occipital lobe, specifically in the visual cortex.
C. Option C (loss of speech): Ablation of somatosensory area V should not cause speech impairments, as speech is processed in the Broca's area (inferior frontal gyrus) and Wernicke's area (temporal lobe).
D. Option D (loss of memory): Ablation of somatosensory area V does not result in memory deficits, as memory is primarily processed in the hippocampus and surrounding structures, not the somatosensory cortex.
**Clinical Pearl:** Mapping of brain functions to specific regions in the cerebral cortex is crucial for understanding neurological deficits and guiding surgical procedures. The principle of "functional specialization" ensures that specific brain regions are dedicated to particular functions, minimizing the risk of causing unwanted side effects by targeting other areas.
**Correct Answer:** C. Loss of touch sensation in the corresponding body parts (upper limbs and face).
Ablation of the somatosensory area V leads to a loss of touch sensation in the upper limbs and face, as it is responsible for processing tactile information from these regions. This is due to the disruption of the neural pathways originating from these body parts, which are then transmitted to other regions of the brain responsible for higher cognitive functions like perception, integration, and discrimination of touch sensations.