Final answer:
Receptors such as Toll-like receptors (TLRs) are called pattern recognition receptors, which allow the detection and immune response against pathogens by binding to pathogen-associated molecular patterns (PAMPs) on the pathogens.
Step-by-step explanation:
Receptors such as Toll-like receptors (TLRs), NOD-like receptors (NLRs), RIG-like receptors (RLRs), scavenger receptors are pattern recognition receptors (PRRs). These receptors on immune cells allow the detection of pathogens by binding to pathogen-associated molecular patterns (PAMPs).
TLRs are membrane-bound receptors that play a crucial role in the innate immune system by recognizing molecular patterns that are broadly shared by pathogens but are distinguishable from host molecules. They are found on immune cells like phagocytes, which engulf and destroy foreign particles and pathogens. TLRs, as a type of PRR, identify features of pathogens such as bacterial cell wall components or bacterial flagellar proteins.
The innate immune system uses these limited PRRs to recognize and respond to a broad diversity of pathogens, which contrasts with the adaptive immune system that uses many different highly specific receptors. When PRRs like TLRs bind to PAMPs, they initiate mechanisms like phagocytosis or cellular apoptosis to eliminate the infectious agents.