Question

Read each description below regarding the different ways to classify receptors.

1. Receptors associated with cranial nerves
2. Nociceptors
3. Chemoreceptors
4. Exteroreceptors
5. Photoreceptors
6. Receptors widely distributed in the skin
7. Interoreceptors

a. Stimulus Modality
b. Stimulus Origin
c. Receptor Distribution

Answer 1

Answer:

a. Stimulus Modality:

2. Nocireceptors

3. Chemoreceptors

5. Photoreceptors

b. Stimulus Origin:

4. Exteroreceptors

7. Interoreceptors

c. Receptor Distribution:

1. Receptors associated with cranial nerves

6. Receptors widely distributed in the skin

Explanation:

Receptor:

A receptor or sensory receptor is structure, particularly protein in nature that detects stimuli.

Receptors are widely classified based on three major characteristics of the stimulus or the receptor:

1. Stimulus Modality
2. Stimulus Origin
3. Receptor Distribution

Stimulus Modality:

Stimulus modality or sensory modality is defined as one aspect of a particular sensory stimulus. It basically is a subtype of sensory stimuli. For example, pain, temperature, pressure, light all are subtypes of a sensory stimulus. Receptors included in this category are:

• Nocireceptors
• Chemoreceptors
• Mechanoreceptors
• Thermoreceptors
• Photoreceptors

Stimulus Origin:

The external or internal origin of the stimulus also defines the type of receptors. These include:

• Exteroreceptors that detect external stimuli.
• Interoreceptors that detect internal stimuli.

Receptor Distribution:

On the basis of distribution, receptors are of two categories:

• Widely distributed for sensing general stimuli.
• Localized receptors that are specialized for one or two types of stimuli.