Question

Death from amyotrophic lateral sclerosis usually results from respiratory infection secondary to compromised respiratory function.

II. Name three each of unencapsulated and encapsulated sensory receptors and tell what they are used for.

III. What would be the advantage of having a nerve come from a spinal nerve plexus? Explain, using an example of such a nerve and a potential damage to it.

Answer 1

Question 1

Amyotrophic lateral sclerosis is also called Gehrig disease. It is the neuromuscular disease. This condition characterized by progressive destruction of motor neurons in the lateral horn and the pyramidal tracts. In advanced condition the disease leads to loss or difficulty in breathing, speaking, swallowing. The lungs are unable to expand completely, increased respiratory secretions and difficulty in respiration and respiratory infection. All these conditions may lead to death.

Question 2

The unencapsulated sensory receptor nerve endings are

S.No	Receptor	Use
1	Nociceptors	Response to Pinching, Chemical damaged tissue
2	Thermoreceptors	Response to cold and heat
3	Light receptors	Response to touch and light. It consists of hair receptors.

The encapsulated sensory receptor nerve endings are

S.No	Receptor	Use
1	Joint kinesthetic receptors	Response to stretch of the articular capsule
2	Muscle spindles	Response to muscle stretch
3	Pacinian corpuscles	Response to vibration and deep pressure
4	Meissner's (tactile) corpuscles	Response to discriminative touch
5	Golgi tendon receptors	Stretch in tendons