Answer:
Sensory nerve receptors are not able to send out messages to the brain indefinitely.
Step-by-step explanation:
Receptors can be defined as protein molecules that are located inside the target cell or on its surface that receive a chemical signal. Chemical signals are released by signaling cells in the form of little, usually volatile or soluble molecules known as ligands. A ligand is a molecule that binds another specific molecule, in some cases, transporting a signal in the process. Ligands can therefore be described as signaling molecules. Ligands and receptors exist in several forms; however, a specific ligand will have a specific receptor that typically binds with only that ligand.
The loss of sun glasses on top of our head is due to the fact that the sensory nerve receptors are not able to send out messages to the brain indefinitely.