What does the word homunculus mean?
1 : a little man : manikin. 2 : a miniature adult that in the theory of preformation is held to inhabit the germ cell and to produce a mature individual merely by an increase in size.
What is homunculus in anatomy?
A cortical homunculus is a distorted representation of the human body, based on a neurological “map” of the areas and proportions of the human brain dedicated to processing motor functions, or sensory functions, for different parts of the body.
Why is the homunculus important?
The cortical homunculus represents the importance of various parts of your body as seen by your brain. There is little need for the brain to know what’s going on in the arms and legs. As a result, they take up a lot of brain space.
Why are the motor and sensory homunculus anatomically deformed?
The reason for the distorted appearance of the homunculus is that the amount of cerebral tissue or cortex devoted to a given body region is proportional to how richly innervated that region is, not to its size. The homunculus is like an upside-down sensory or motor map of the contralateral side of the body.
What are brain gyri?
In neuroanatomy, a gyrus (pl. gyri) is a ridge on the cerebral cortex. It is generally surrounded by one or more sulci (depressions or furrows; sg. sulcus). Gyri and sulci create the folded appearance of the brain in humans and other mammals.
Why is the brain so folded?
To enable its expansion, the brain forms folds during fetal development that allow fitting the enlarged neocortex into the restricted space of the skull. This part of the brain has expanded greatly in human evolution, and a key aspect of this expansion is the folding of the cortical surface.
Is your brain folded?
Cortical folding, or gyrification, coincides with several important developmental processes. The folded shape of the human brain allows the cerebral cortex, the thin outer layer of neurons and their associated projections, to attain a large surface area relative to brain volume.