What does sensory homunculus mean?
The sensory homunculus is a topographic representation of the sensory distribution of the body found in the cerebral cortex. This topograph usually has body parts illustrated along the surface of the postcentral gyrus of the parietal lobe.
Why are the fingers lips and tongue so large on the sensory homunculus?
Many brain cells control sensation and movement of the lips so make a big lip for the homunculus. Technically, brain cells that control the tongue are found below the area that represents the lip, but to make the tongue easy to identify, we stuck it in between upper and lower lips.
Why does the homunculus look so strange?
And finally, the homunculus on the sensory cortex looks barely human. It has a large representation of the face and hands compared with the torso, arms and legs. Why is this? The reason is the brain maps each sensory receptor onto the cortex rather than considering the area of the body where the sensor is located.
What is the purpose of a sensory homunculus?
A sensory homunculus represents a map of brain areas dedicated to sensory processing for different anatomical divisions of the body. The primary sensory cortex is located in the postcentral gyrus, and handles signals coming from the thalamus.
Why are the lips and tongue so big in the homunculus?
This larger area allows you to make finer movements and a have better sense of touch. The area of your brain devoted to each body part is represented in the homunculus by how large each body part is. Looking at the illustration above, it should now make sense to you why the lips and tongue are so large and the knee is so small.
Which is the most sensitive part of the homunculus?
The sensory homunculus is a distorted human model in which the sensitive parts such as lips, tongue, palms and fingers are larger. But in the most common representations of the sensory homunculus something quite sensitive is omitted or its sensitivity is severely undervalued.
How is the motor homunculus different from the sensory homuncce?
The motor homunculus is very similar to the sensory homunculus, but differs in several ways. Specifically, the motor homunculus has a portion for the tongue most lateral while the sensory homunculus has an area for genitalia most medial and an area for visceral organs most lateral.
Where are the sensory neurons located in the homunculus?
In the sensory homunculus, below the areas handling sensation for the teeth, gums, jaw, tongue, and pharynx lies an area for intra-abdominal sensation. At the very top end of the primary sensory cortex, beyond the area for the toes, it has traditionally been believed that the sensory neural networks for the genitals occur.
