PATHOLOGY

Detailed explanation-1: -There are three general categories of cell-surface receptors: ion channel-linked receptors, G-protein-linked receptors, and enzyme-linked receptors. Ion channel-linked receptors bind a ligand and open a channel through the membrane that allows specific ions to pass through.

Detailed explanation-2: -Receptors are protein molecules in the target cell or on its surface that bind ligands. There are two types of receptors: internal receptors and cell-surface receptors.

Detailed explanation-3: -One important family of intracellular receptors are the nuclear receptors (also known as ‘nuclear hormone receptors’), which includes receptors for steroid hormones, thyroid hormones, retinoids and vitamin D.

Detailed explanation-4: -Types of Ligands. Ligands are the signaling molecule used by the body for various cells to communicate with other cells. Internal Receptors. These receptors are also known as either intracellular or cytoplasmic. Cell-Surface Receptors. Ion Channel Receptors. GPCRs. Enzyme-Linked Receptors.