erregbaren

Erregbaren is a German adjective used in biology to describe cells, tissues, or organisms that can be excited by stimuli and respond with rapid signals, typically electrical changes in the cell membrane. In this sense, erregbare structures are capable of generating and propagating signals such as action potentials, enabling fast communication, processing of information, and coordinated movement.

The core mechanism of excitability involves the resting membrane potential, specialized ion channels (including voltage-gated and ligand-gated channels), and the threshold that must be reached for activation. When depolarization brings the membrane potential to threshold, voltage-gated channels open, causing a rapid change in voltage (an action potential) followed by a return to resting conditions via ion pumps and channels. This all-or-none event can travel along neurons or muscle fibers, producing nerve impulses or muscle contractions.

Examples of erregbare tissues include neurons and muscle—skeletal, cardiac, and smooth muscle cells—where excitability underpins neural signaling and muscle activity. Some plant cells and certain unicellular organisms also exhibit excitable properties, though they are less commonly grouped with animal excitable tissues.

The term contrasts with non-erregbare tissues that do not generate action potentials in response to typical stimuli. Physiological or pathological changes can modulate excitability, leading to states of hypo- or hyperexcitability, with implications for signaling, reflexes, and movement.