Question

TEST Tour knowledge Match the receptor with the sensation with which it is most associated 1. free nerve endings (a) light touch; hot and cold 2. Ruffini corpuscle (b) sustained touch and pressure 3. Pacinian corpuscle (c) sustained pressure 4. Meissner's corpuscle (d) changes in texture, slow vibrations 5. Merkel's discs (e) deep pressure, fast vibrations 6. The motor cortex is the - gyrus. 7. Define sensory adaptation 8. Name a sensory modality that adapts quickly kyrus of the cerebral cortex, the sensory cortex is the name one that adapts slowly, if at all: pain 9. Angina pectoris is an example of a(n) 10. Pain perceived in an amputated limb is known as the Test Your Understanding which parts of your body have the highest density of touch pornton What benefits may be derived from that fact 12. What does the map of the sensory cortex reveal about the density of touch receptors? Explain. 13. How did your right and left hands feel when placed in the same lukewarm water-bath? Explain how this occurred. 14. Describe the importance of referred pain in the diagnosis of deep visceral pain and give examples.

Answer 1

Matching the receptor with the sensation with which it is most associated:

The correct matching is:

1 a

2 c

3 e

4 d

5 b

Justification:

1. Free nerve endings - light touch; hot and cold. Free nerve endings are sensitive to light touch; hot and cold because they are slow to adjust to a stimulus and so they are less sensitive to the changes in stimulation.

2. Ruffini corpuscle - Sustained pressure. Ruffini corpuscle is sensitive to Sustained pressure because they shows very little adaptation to pressure.

3. Pacinian corpuscle - deep pressure; fast vibrations. Pacinian corpuscle is sensitive to deep pressure and fast vibrations because it is a mechanoreceptor which can sense deep or transient pressure and high-frequency vibrations.

4. Meissner's corpuscle - changes in texture; slow vibrations. Meissner's corpuscle is sensitive to changes in texture and slow vibrations because the function of meissner's corpuscle is to detect the changes in texture and slow vibrations.

5. Merkel's discs - Sustained touch and pressure. Merkel's discs are sensitive to sustained touch and pressure.

6. The motor cortex is the precentral gyrus of the cerebral cortex; the sensory cortex is the postcentral gyrus.

Justification: Motor cortex is the area of frontal lobe which is located in the posterior placental gyrus and anterior to central sulcus. Central cortex is located in the lower posterior lobe of frontal lobe and insula.

7. Sensory adaption: Sensory adaptation refers to contraction in sensitivity to a stimulus, after constant exposure to it. It reduces our sensation to a constant stimulus. For example, our sense of smell quickly adapts to odors of a laboratory.

8. Name a sensory modality that adapts quickly: touch.

Name one that adapts slowly, if at all: pain.

Justification: Touch adapts quickly because it responds to a change in stimulus very quickly. It can sense immediately when the skin is touching an object and when it stops touching that object. In the same way, pain adapts slowly because it responds to a change in stimulus very slowly.

9. Angina pectoris is an example of referred pain.

Justification: Referred pain is the pain which is experienced at a location other than at the site of painful stimulus, which means pain is located away from the organ involved in the pain. Angina pectoris is an example of referred pain because it carries pain fibers from other regions like arm, neck, etc.,

10. Pain perceived in an amputated limb is known as the Phantom limb phenomenon.

Justification: Because phantom limb is a sensation which still attaches a missing or amputated limb. We can sense phantom sensations in the amputed or missing limb.

11. Our body has highest density of touch receptors on the face, lips and fingertips. We can have benefits for touch receptors on these parts to identify the objects, temperatures, textures and all.

12. The map of sensory cortex reveals the analysis of cutaneous sensations due to its larger area of cortex. These Cutaneous sensations arise from the fingertips of hands, tongue, lips and from other such organs of the body.

Thank you!