What is the difference between a receptor and an effector?

Question

What is the difference between a receptor and an effector?

Answer 1

A receptor is a structure which receives something, while an effector carries out a task.  For example the photo receptors in the eyes receive photons of light.  Stretch receptors in the muscles detect the amount of stretch in those muscles.  In both these cases the receptors are neural and so the response is to fire an action potential.  You can also have hormonal receptors eg glucose receptors on your islet cells in the pancreas.

The effectors are the organs which respond to the signals generally triggered by these receptors.  eg when you hit your knee with a reflex hammer the stretch receptors in your quadraceps muscles detect the stretch, fire an action potential (the signal) to your spinal cord, where they synapse with motor neurons which run back to the stretched muscle, causing it to contract.  In this case the effector is the quadriceps muscle since it is the thing that carries out the function triggered by the signal.

In the case of high blood glucose the receptors are glucose receptors on your beta islet cells in your pancreas, which then produce the signal (insulin).  Body cells such as muscle cells or liver cells would be the effectors as they then receive the signal and act on it, ie absorb glucose.

Answer 2

In a sensory system, a sensory receptor is a structure that recognizes a stimulus in the internal or external environment of an organism. In response to stimuli the sensory receptor initiates sensory transduction by creating graded potentials or action potentials in the same cell or in an adjacent one.

In biochemistry, a receptor is a protein molecule, embedded in either the plasma membrane or cytoplasm of a cell, to which a mobile signaling (or "signal") molecule may attach. A molecule which binds to a receptor is called a "ligand," and may be a peptide (such as a neurotransmitter), a hormone, a pharmaceutical drug, or a toxin, and when such binding occurs, the receptor ordinarily initiates a cellular response, though some ligands merely block receptors without inducing any response. Ligand-induced changes in receptors result in physiological changes which constitute the biological activity of the ligands

An immune receptor (or immunologic receptor) is a receptor, usually on a cell membrane, which binds to a substance (for example, a cytokine) and causes a response in the immune system.

One class of non-self molecules are called antigens (short for antibody generators) and are defined as substances that bind to specific immune receptors and elicit an immune response

An effector is a molecule (originally referring to small molecules but now encompassing any regulatory molecule, includes proteins) that binds to a protein and thereby alters the activity of that protein. A modulator molecule binds to a regulatory site during allosteric modulation and allosterically modulates the shape of the protein.

hope thishelped you :)