Fc receptor

Fc re·cep·tor

receptors present on a variety of cells for the Fc fragment of immunoglobulins. These receptors recognize immunoglobulins of the IgG and IgE class.

Fc receptor

A receptor on phagocytes (neutrophils, monocytes, and macrophages) that binds Fc fragments of immunoglobulins G and E.

See: immunoglobulin; macrophage processing; phagocytosis

See also: receptor

receptor

1. a molecule on the surface or within a cell that recognizes and binds with specific molecules, producing some effect in the cell, e.g. the cell-surface receptors of immunocompetent cells that recognize antigens, complement components or lymphokines, or those of neurons and target organs that recognize neurotransmitters or hormones; see also opioid receptors.

2. a sensory nerve ending that responds to various stimuli, e.g. arterial stretch, baroreceptors, cold, Golgi tendon organs, joint, muscle and tendon, olfactory, retinal, taste and warmth.

---

receptor activation

the cell of a sensory receptor responds to a specific energy change in its environment and initiates a corresponding sensory input.

adrenergic r's

receptors for epinephrine or norepinephrine, such as those on effector organs innervated by postganglionic adrenergic fibers of the sympathetic nervous system. Classified as α-adrenergic receptors, which are stimulated by norepinephrine, and β-adrenergic receptors, which are stimulated by epinephrine. See also adrenergic receptors.

autonomic r's

includes adrenergic and muscarinic receptors.

cholinergic r's

receptor sites on effector organs innervated by cholinergic nerve fibers and which respond to the acetylcholine secreted by these fibers. There are two types: muscarinic receptors and nicotinic receptors.

complement receptor

a cell-surface receptor capable of binding activated complement components. For example, component C3b is bound to neutrophils, B lymphocytes and macrophages.

dopamine r's

there are dopamine-inhibitory and dopamine-excitatory receptors.

drug receptor

a component of tissue with which a drug reacts. Classified according to the type of drugs that react with them.

Fc receptor

bind immunoglobulins via Fc part of the molecule.

histamine r's

receptors for histamine, classified as H1-receptors, which produce bronchoconstriction and contraction of the gut and are blocked by antihistamines, such as mepyramine or chlorpheniramine, and H2-receptors, which produce gastric acid secretion and are blocked by H₂-receptor blockers, such as cimetidine.

muscarinic receptor

see muscarinic receptors.

nicotinic receptor

see nicotinic receptors.

peripheral receptor

sensory receptors including cutaneous warm and cold, dermoreceptors touch and pain plus receptors in the mucosae.

sensory receptor

an endorgan at the end of an afferent neuron which is capable of stimulation by a specific change, physical or chemical, in the internal or external environment of the patient.

toll-like r's

a family of transmembrane proteins that differentially recognize pathogen-associated molecular patterns through an extra cellular domain and initiate inflammatory signaling pathways through an intracellular domain; they play a central role in the innate immune response to pathogens.

receptor tyrosine kinases

a large class of cell-surface receptors with tyrosine-specific protein kinase activity.