What type of receptor is responsible for monitoring blood pH and concentrations of oxygen and carbon dioxide?

The type of receptor responsible for monitoring blood pH and concentrations of oxygen and carbon dioxide is indeed a chemoreceptor. Chemoreceptors are specialized sensory receptors that respond to chemical stimuli in the environment. In the context of blood monitoring, they play a crucial role in detecting changes in the chemical composition of the blood, particularly the levels of oxygen (O2), carbon dioxide (CO2), and pH.

These receptors are crucial for homeostasis, as they provide the necessary information for the respiratory and cardiovascular systems to maintain optimal levels of gases and pH in the body. The central chemoreceptors, located in the medulla oblongata, are primarily responsible for sensing changes in carbon dioxide levels and pH, while peripheral chemoreceptors found in the carotid and aortic bodies monitor oxygen levels.

The other types of receptors mentioned do not play a role in this specific function. Mechanoreceptors respond to mechanical forces such as pressure or deformation (think of touch and proprioception), photoreceptors are sensitive to light and involved in vision, and thermoreceptors are specialized for detecting changes in temperature. Thus, the chemoreceptor is specifically designed to sense chemical changes in the blood, making it the correct answer for this question.