outgrowth

Outgrowth refers to any projection or extension that grows outward from a body, organ, tissue, or cell. It can be a physical appendage, such as a bone spur; a cellular extension like a neurite; or a botanical shoot, root, or bud. In biology, outgrowths arise through development or regeneration and are shaped by genetic programs and environmental cues.

In the nervous system, neurite outgrowth is the process by which developing neurons extend axons and dendrites to connect with target cells. Growth cones at the tips sense chemical and mechanical signals and steer elongation by reorganizing the cytoskeleton.

In plants, outgrowths include root hairs—epidermal extensions of root cells that increase surface area for absorption—and lateral shoots or buds that emerge from the plant body. Some outgrowths are specialized structures such as trichomes or tubers.

In medicine and anatomy, outgrowths describe protrusions from tissues, which may be benign or pathological. Osteophytes are bone outgrowths commonly seen near joints; polyps are mucosal outgrowths that can occur in the gastrointestinal tract, nasal passages, or other cavities.

In broader usage, outgrowth can refer to any development or extension from a parent structure, including embryonic limb buds or other morphological features observed in anatomy, botany, or pathology.