Leprosy, Caused by the Bacterium Mycobacterium Leprae

A- Leprosy, caused by the bacterium Mycobacterium leprae, is a leading cause of peripheral neuropathy worldwide; although it is treatable, the damage caused by the disease is irreversible. In Sannu's case, why is there both sensory loss and muscle weakness?

Sannu has suffered from repeated injuries and malnutrition. Because of the repeated injuries he is suffering from repeated nerve damage. When someone has leprosy and it goes untreated, the can lose sensation in the affected extremity due to the body's defense mechanism. This can cause loss of feeling in the skin and weakens the muscle. Being malnourished and not receiving proper treatment has not helped the disease.

B- Leprosy can affect the skin and Schwann cells of peripheral nerves. Which events of sensation processing are most likely not functioning properly in Sannu's leprosy?

The generation of nerve impulses in Sannu is probably not working correctly. Sensory neurons conduct impulses from the peripheral nervous system, so when the leprosy affects the Schwann cells of the peripheral nerves it is not conducting the impulse to integrate the sensory input.

C- Were somatic, visceral, or special senses being investigated when Dianna evaluated Sannu's Achilles and Babinski reflex activity?

No, special senses were not being investigated on Sannu. Only visceral and somatic were being evaluated. Also, checking sensation by pressure and reflexes rather than vision, hearing, and taste.

D- Sannu has lost sensations of pain, temperature, light touch, and pressure. What types of receptor endings mediate the detection of these sensations?

Free nerve endings are receptors for pain, temperature, itch, and some touch sensations. Encapsulated nerve endings are receptors for pressure, vibration and also some touch.

E- Leprosy infects the body via the skin, typically in the cooler regions of the body. Based on this information, would you expect Sannu's interoceptors to be affected?

Yes, interoceptors produce impulses that usually are not consciously perceived but they occasionally may be felt as pain or pressure, which Sannu has none in his feet and hands.

F- Sannu describes pain in his leg. What receptors mediate sensations of pain? What type of pain is Sannu's "burning" pain, fast or slow?

The receptors that mediate sensations of pain are nociceptors. The type of "burning" pain that Sannu is experiencing is slow pain.

G- What type of peripheral receptors would be activated in a normal, intact limb to produce the sensations Sannu is experiencing in his "phantom limb"?

The type of peripheral receptors that would be activates in a normal, intact limb that produces the sensations that Sannu is experiencing in his phantom limb are proprioceptors.

H- Sannu has experienced two devastating