Answer:
<u>Pruning</u>
Explanation:
Pruning or synaptic pruning is brain's way of clearing unnecessary signals that are no longer needed. It mostly occur in childhood and adolescence because brain want to get faster by avoiding unused impulses in Synapses. Synapse is the space between neurons through which signals are being transferred.
Although in many regions of the brain—particularly those that give rise to nuclear cell groups—neurons migrate without the benefit of glial guides, migration along radial glial fibers is always seen in regions where cells are organized into layers, like the cerebral cortex, hippocampus, and cerebellum.
Complementary nature of structure and function.
Bodies of molluscs are subdivided into three parts:
*The head that contains the sensory organs and the mouth that contains the radula and odontophores (absent in bivalves).
*The foot is a muscular organ, typical of molluscs, intended for locomotion. It has different shapes depending on the species.
*The visceral mass, as the name suggests, contains the viscera. It is contained in a thin tunic called the coat. It is the mantle that secretes the shell of most molluscs, which serves as protection and / or skeleton and / or regulator of flotation.
Between the mantle and the visceral mass, the pallial rim constitutes a pallial cavity that protects the respiratory organs, and where the metanephridia (excretory organs), the intestine and the genital ducts open.
The hitchhike sign represents the extension of the thumb and it is used to identify two different conditions: radial nerve or posterior interosseous nerve palsy and diastrophic dwarfism.
If there is radial nerve lesion then weakness of brachioradialis and finger flexion occurs. <span>If there is a posterior interosseous nerve lesion then weakness of finger extension occurs.</span>
