Question

Would you have expected to find more tactile corpuscles and Merkel discs on the palm or on the posterior shoulder? Why?

A. Palm, because it has more sensory receptors.
B. Posterior shoulder, because it is less exposed to external stimuli.
C. Palm, because it undergoes more frequent tactile stimulation.
D. Posterior shoulder, because it has a thicker epidermal layer.

Answer 1

More tactile corpuscles and Merkel discs are found on the palm as it undergoes more frequent tactile stimulation and has a higher concentration of these touch receptors, which are specialized for fine touch discrimination.

Step-by-step explanation:

You would expect to find more tactile corpuscles (Meissner's corpuscles) and Merkel discs on the palm than on the posterior shoulder. This is because the palm undergoes more frequent tactile stimulation and has a higher density of sensory receptors that are specialized for fine touch discrimination.

Merkel discs are associated with the sense of light touch and the discrimination of shapes and textures, while Meissner's corpuscles, which are found in the upper dermis but project into the epidermis, respond to fine touch and pressure, and low-frequency vibration or flutter. They are both abundant in areas of the skin that are sensitive and used for detailed exploration such as the fingertips, which is consistent with needing a high resolution of touch perception in these areas. The palm of the hand contains a greater number of these receptors compared to areas like the posterior shoulder, which is not as involved in tactile exploration and sensation.

The correct answer is C. Palm, because it undergoes more frequent tactile stimulation.