When You're the One Canceling a Flight. In defense of Spirit, most airlines operate on razor thin margins and refund dollars do add up. Even airlines that allow refunds-generally only under very special circumstances-may make you jump through hoops and even pay a fee.
Medical Definition of receptor. 1  1: a cell or group of cells that receives stimuli : sense organ. 2  2: a chemical group or molecule (as a protein) on the cell surface or in the cell interior that has an affinity for a specific chemical group, molecule, or virus.
The olfactory membrane is a thick yellow-brown structure, about one inch square, located in the upper part of each nasal cavity.It consists of about one hundred million smell receptor cells, which are surrounded by supporting cells.The smell receptor cells have an olfactory vesicle bearing cilia, which project into the mucus that covers the smell membrane.Chemicals in the air react with the cilia and stimulate the receptor cells.he smell receptor cells have an olfactory vesicle bearing cilia, which project into the mucus that covers the smell membrane. Chemicals in the air react with the cilia and stimulate the receptor cells.