1. A molecular structure within a cell or on the surface characterised by selective binding of a specific substance and a specific physiologic effect that accompanies the binding, for example, cell surface receptors for peptide hormones, neurotransmitters, antigens, complement fragments and immunoglobulins and cytoplasmic receptors for steroid hormones.

2. A sensory nerve terminal that responds to stimuli of various kinds.

This entry appears with permission from the Dictionary of Cell and Molecular Biology

(11 Mar 2008)