6A: Other Senses

Question 1

____________ is an an adaptive ability to make us aware of an injury and motivate us to remove ourselves fr the cause of that injury.

Answer 1

Somatosensation is an an adaptive ability to make us aware of an injury and motivate us to remove ourselves fr the cause of that injury.

• sensed pain can either be inflammatory (signaling tissue damage) or neuropathic (exaggerated pain signals due to neuronal damage).

Question 2

What are the four types of somatosensation?

Answer 2

Somatosensation types:

• Thermoception
• Mechanoception (pressure)
• Proprioception
• Nociception (pain)
  
  • Incl pain fr all types of stimuli, e.g. mechanical, heat, chem, etc.

Question 3

Thermo-, mechano-, proprio-, and nociception are types of somatosensation. What info is gathered w ea type?

Answer 3

Somatosensation: Intensity, Timing, and Location.

Question 4

The ________ of a sensation refers to how quickly neurons fire.

Answer 4

The intensity of a sensation refers to how quickly neurons fire.

• As stim intensity ↑ → rate of AP firing ↑.

Question 5

In what three ways do neurons encode the timing of a stimulus?

Answer 5

Timing: Neuron encodes 3 ways for timing: non adapting, fast adapting, or slow adapting.

• Non-adapting: rate of AP firing is constant.
• Slow-adapting: rate of AP firing gradually ↓.
• Fast-adapting: APs fired w initial stim → pause → fired again when stim removed.

Question 6

Location-specific stimuli by nerves is sent to brain via __________.

Answer 6

Location-specific stimuli by nerves is sent to brain via dermatomes.

Question 7

Differentiate sensory adaptation and amplification.

Answer 7

Adaptation - change over time of receptor to a constant stimulus; down regulation.

• W/o change in stim, AP not sent to brain.
• Imp bc if cell overexcited → cell can die.
• E.g. push down on surface w hand → receptors experiences constant pressure → receptors cease firing after a few seconds.

Amp - opp of sensory adaptation; up regulation.

• E.g. light hits photoreceptor in eye → cell fires AP → causes 2+ to fire AP → etc → amplified AP sent ot brain.

Question 8

The somatosensory __________ is a topological map of entire body in the somatosensory ______ (sensory strip) of _______ lobe.

Answer 8

The somatosensory homunculus (little man) is a topological map of entire body in the somatosensory cortex (sensory strip) of parietal lobe.

Question 9

Nociception and thermoception are considered relatively (fast/slow) sensations and rely on _____ receptors.

Answer 9

Nociception and thermoception are considered relatively slow sensations and rely on TrypV1 receptors.

Question 10

Thermoception relies on TrypV1 receptors. Describe the mechanism of action.

Answer 10

Thermoception & TrypV1 receptors:

• Heat → cells break down and release diff ligands of TrypV1 → ligands bind TrypV1 → conform change → cell depols → AP.