| cholinergic receptors | Chemical sites in effector cells or at synapses through which acetylcholine exerts its action. (05 Mar 2000) |
|---|---|
| muscarinic receptors | Membrane-bound proteins whose extracellular domain contains a recognition site for acetylcholine (ACh); combination of Ach with the receptor initiates a physiologic change (slowing of heart rate, increased glandular secretory activity and stimulation of smooth muscle contractions); changes are observed after treatment with the mushroom alkaloid, muscarine. Muscarinic receptors are to be distinguished from nicotinic receptors. (05 Mar 2000) |
| saturation of receptors | Saturation, the state in which all receptors are effectively occupied all the time, can be said to occur in a simple binding equilibrium when the concentration of ligand is more than 5 times the Kd value, although strictly this will only be true at infinite ligand concentration. (18 Nov 1997) |
| pulmonary stretch receptors | Stretch receptors found in the bronchi and bronchioles. Pulmonary stretch receptors are sensors for a reflex which stops inspiration. In humans, the reflex is protective and is probably not activated during normal respiration. (12 Dec 1998) |
| sensory receptors | Peripheral endings of afferent neurons. (05 Mar 2000) |
| stretch receptors | Receptor's that are sensitive to elongation, especially those in Golgi tendon organs and muscle spindles, but also those found in visceral organs such as the stomach, small intestine, and urinary bladder; these receptor's have the function of detecting elongation, and this distinguishes them from baroreceptors, which actually are activated by stretching of the wall of the blood vessel but whose function is to elicit central reflex mechanism reducing the arterial blood pressure. (05 Mar 2000) |
| nicotinic receptors | A class of cholinergic receptors on skeletal muscle cells that are linked to ion channels in the cell membrane. (05 Mar 2000) |
| opiate receptors | Regions of the brain which have the capacity to bind morphine; some, along the aqueduct of Sylvius and in the centre median, are in areas related to pain, but others, as in the striatum, are not related. (05 Mar 2000) |
| T-cell antigen receptors | Receptors present on T-cells that interact with both processed antigen and major histocompatibility antigens simultaneously. (05 Mar 2000) |
| low-density lipoprotein receptors | Receptors on the surface of cells, especially liver cells, which bind to low density lipoprotein and promote clearance of LDL from the plasma. (05 Mar 2000) |