Question

Which of the following receptor classifications could be considered enteroreceptors?
A. Chemoreceptors
B. Photoreceptors
C. Visceroreceptors
D. Both (A) and (C)

Answer 1

Any receptor that responds to stimuli inside the body is called Enteroreceptor.
It is also termed as Interceptor. This was invented by Sir Charles Scott Sherrington. He was an English physiologist whose $50$ years of research resulted in the foundations for an understanding of integrated nervous function in higher animals and brought him the Nobel Prize for Physiology or Medicine in $1932$.

Complete Answer:
Option A - Chemoreceptors and Option C – visceroreceptors, they both respond to stimuli inside the body and they can be considered under enteroreceptors.
So, the correct answer is Option D - 'Both (a) and (c)'.
Option A Chemoreceptors: This consists of aortic and carotid bodies. Aortic body notices changes in blood oxygen and carbon dioxide but not pH while the carotid body notices all three.
So, option A is correct.
Option B Photoreceptors: Photoreceptors are specialized neurons found in the retina. They alter light into electrical signals that stimulate physiological processes. There are two diverse types of receptors in the retina of each eye. They are in authority for the perception of fine detail and color (cone cells) and brightness (rod cells).
So, option B is not correct.
Option C Visceroreceptors: A group of receptors that includes those situated in visceral organs. Their stimulation gives increase to poorly localized and ill-defined feelings or to pain. In hollow visceral organs they are stimulated mainly by extreme contraction or by distention.

So, option C is the correct answer.

Note:
Receptors are protein particles inside the target cell or they are situated on its surface that receives a chemical signal. Chemical signals are discharged by signaling cells in the form of small, generally unstable or soluble particles that are called ligands. A ligand is a particle that binds another precise particle, sometimes delivering a signal in the process. Hence Ligands can be assumed as the signaling molecules. Ligands and receptors exist in a number of varieties. Though, a particular ligand will have an exact receptor that typically binds only that ligand.