Dendritic

Dendritic is an adjective meaning tree-like or branched in a pattern reminiscent of a tree. The term comes from the Greek dendron, meaning tree, and is used across science to describe structures with extensive, branching extensions.

In neuroscience, dendrites are the branched projections of neurons that receive synaptic inputs. The dendritic arbor can be highly complex, and dendritic spines provide additional surface area for synapses. The geometry and plasticity of dendrites influence how neurons integrate signals and adapt during development, learning, and disease. Abnormal dendritic structure or atrophy is observed in several neurological conditions.

Dendritic cells are a class of antigen-presenting cells in the immune system. They capture, process, and present antigens to T cells, initiating adaptive immune responses and contributing to tolerance. Dendritic cells reside in tissues in contact with the external environment and in lymphoid organs; they mature in response to pathogens or inflammatory signals.

In crystallography and materials science, dendritic growth describes tree-like crystal morphologies that form during solidification, often under diffusion-limited conditions. Dendritic microstructures influence the mechanical properties of metals and alloys and can lead to porosity or segregation if not controlled.

Geologically, dendritic patterns can appear in rocks as manganese or other mineral dendrites. These are mineral precipitates that resemble plant-like branching and form by diffusion and chemical gradients rather than organic growth.

The term is also used more broadly in botany to describe highly branched or vein-like patterns, including dendritic venation or root and shoot branching in certain plants.