Question

Doing a packet for physiology lab. The lab is titled Sensory Lab. we are suppose to use our own eye sight( mine is 20 20 vision with pretty good-average. both eyes are 0/ 0.

Questions asked:

1. explain the process of activating a sensory neuron

2. What is the anatomical basis for the blind spot

3. where was your tactile discrimination the best? what can you say about the density of tactile receptors on your arm?

4. what happened when you placed your hands from the hot and cold water to the lukewarm water? why do you think this happened?

5. What can you say about the distribution of the different types of taste receptors?

6.What is the primary difference between fast pain and slow pain?

Answer 1

1 . A neuron that works with sensory receptors are specialized to encage with and detect specific stimulus.sensation refers to the process of sending our environment through touch ,taste ,sound ,smell and sight. A sensory system consist of sensory receptors ,neural pathways and parts of the brain involved in sensory perception.Stimulation of the sensory neuron activate the associated afferent neuron which carries information about the stimulus to central nervous system.

All sensory receptors receive distinct physical stimuli and transduce the signal into an electrical action potential. This action potential then travels along different neurons to specific brain region where it is processed and interpreted.

2. Blind spot is a small portion of the visual field of each eye that corresponds to the position of optic disk within the retina.There are no photoreceptors ( rods and cones) in the optic disk and therefore no image is detected in this area. The optic nerve fiber exit the back of the eye at blind spot. The blind spot is located about 15 degrees to the nasal side of the fovea. The retina and optic nerve meet each other at the blind spot.

3.The tip of the tongue, lips and fingertips are more sensitive to tactile descrimination than cheeks and back of hands. In arm most of density of tactile receptor is more in finger tips.

4 .If we Keep our hands in cold or hot water for a long time our nerve receptors will get used to the temperature of water.Hot water cause vasodilation and increase blood flow , bt in cold water vasoconstriction occurs leading local blood circulation. So contrast bath therapy is used to improve circulation.

5.​​​​6. Fast pain goes away far quickly and comes from the stimulation and transmission of nerve impulse over A delta fibres ,while slow pain persists longer and comes from the stimulation and transmission over non- myelinated C fibres.