Video Transcript
You feel a sharp pinch in your arm as you are having an injection. Which of the following receptors will be most likely to detect the stimulus? (A) Chemical receptors in the skin. (B) Pain receptors in the skin. (C) Heat receptors in the skin. (D) Pain receptors in the bones. Or (E) pressure receptors in the muscle.
This question presents a number of different receptors in the skin, bones, and muscles. We might remember that a receptor is responsible for detecting stimuli. And these stimuli can come in many forms. When a receptor is activated, it initiates an electrical response in a sensory neuron, which is then transmitted to the spinal cord, which may immediately react, and also to the brain for processing.
Our choices involve four types of receptors: chemical, pain, heat, and pressure. These receptors are responsible for detecting the changes indicated by their names. For instance, chemical receptors will detect changes in the surrounding chemical environment. Some chemical receptors are involved in taste and olfaction, which can detect chemical molecules in the mouth and nose, respectively.
Heat receptors, on the other hand, will detect changes in temperature. Heat receptors give us our perception of how hot or cold something is to the touch. Pain receptors, also called nociceptors, will detect acute and harmful stimuli, such as sharp objects or damage to tissue. These receptors are present in both the skin and internal organs. The resulting signal, passed through the nervous system, produces a painful sensation for the individual. Pressure receptors are also found on the skin and internal organs. These receptors are responsible for detecting a deformation of the receptor caused by increased pressure.
Now that we have reviewed the different types of receptors, we can answer our question. The question states that you feel a sharp pinch in your arm as you’re having an injection. Which type of receptors would be most likely to detect a sharp pinch? This sounds like the injection has caused pain to the individual. Therefore, we can narrow our answers down to (B) and (D), which both indicate pain receptors.
Pain receptors, or nociceptors, respond specifically to harmful stimuli, such as being punctured by a sharp object, and produce a painful sensation as a result. Because injections are made directly through needle-to-skin contact, the receptors that detect the pinch from the needle must be in the skin. Therefore, the correct answer to our question “Which of the following receptors would be most likely to detect the stimulus?” is answer choice (B), pain receptors in the skin.
