Army medical examiners were suspicious about the close proximity of the three bullet holes in Pat Tillmanâs forehead and tried without success to get authorities to investigate whether the former NFL playerâs death amounted to a crime, according to documents obtained by The Associated Press.
Membrane. Definition. noun, plural: membranes. (1) (biology) A thin layer of tissue covering a surface or lining a cavity, space or organ. (2) (biology) A cell membrane. (3) (chemistry) A thin pliable sheet of material that is permeable to substances in solution.Supplement. A biological membrane functions by protecting the surface or bodily organ.1) (biology) A thin layer of tissue covering a surface or lining a cavity, space or organ. (2) (biology) A cell membrane. (3) (chemistry) A thin pliable sheet of material that is permeable to substances in solution. Supplement. A biological membrane functions by protecting the surface or bodily organ.
Receptor: 1. In cell biology, a structure on the surface of a cell (or inside a cell) that selectively receives and binds a specific substance.There are many receptors.There is a receptor for (insulin; there is a receptor for low-density lipoproteins (LDL); etc.To take an example, the receptor for substance P, a molecule that acts as a messenger for the sensation of pain, is a unique harbor on the cell surface where substance P docks.Without this receptor, substance P cannot dock and cannot deliver its message of pain.here is a receptor for (insulin; there is a receptor for low-density lipoproteins (LDL); etc. To take an example, the receptor for substance P, a molecule that acts as a messenger for the sensation of pain, is a unique harbor on the cell surface where substance P docks.