chapter 5: sensory nervous system

Question 1

what is the difference between subconscious and conscious senses?

Answer 1

conscious senses:
-general senses: visceral sensations, hunger, touch, pain, proprioception
-special senses: taste, smell, hearing, vision, equilibrium

subconscious senses: occur outside animals’ awareness; monitored by mechanoreceptors

Question 2

what are the 3 types of sensory receptors?

Answer 2

1. simple receptors: free nerve endings (thermoreceptors, nociceptors/pain)
2. complex neural receptors: nerve endings enclosed in connective tissue capsules (mechanoreceptors, chemoreceptors, photoreceptors)
3. special receptors: neurons with hair cells (receptor in cochlea)

Question 3

explain the pathway of vision.

Answer 3

1. photoreceptors (rods and cones) in retina are activated
2. results in the activation of the optic nerve that transmits an action potential to integrating regions of the brain (thalamus and visual cortex)

Question 4

explain the pathway of hearing.

Answer 4

1. sound is directed into the ear through the pinna and ear canal
2. external ear funnels/collects sound wave vibrations and directs them to eardrum/tympanic membrane
3. vibrations cause middle ear (malleus, incus, stapes) to move
4. fluid in inner ear/cochlea ripples, activating hair cell receptors and CN VIII
5. afferent nerve pathway sends signal to midbrain, thalamus, and auditory cortex

Question 5

explain the pathway of thermoregulation.

Answer 5

1. stimulus: body temp rises or lowers
2. receptor: thermoreceptors in the skin and brain; info sent along afferent pathways to thermoregulatory centers in the brain; info sent along efferent pathways to effectors
3. effectors: sweat glands, arteries in skin
4. body temp returns to homeostatic levels, hypothalamus shuts off signal

Question 6

describe the processes that contribute to nociception/pain

Answer 6

1. nociceptors activated through stimuli
2. transduction
3. transmission
4. modulation
5. perception

Question 7

what is transduction (pain)?

Answer 7

conversion of painful stimuli to action potential

Question 8

what is transmission (pain)?

Answer 8

conduction of action potential to spinal cord

Question 9

what is modulation (pain)?

Answer 9

change to sensory nerve impulses (amplification or suppression of sensory impulses)

Question 10

what is perception (pain)?

Answer 10

conscious awareness of pain

Question 11

how does local anesthesia affect pain reception?

Answer 11

causes the loss of sensory perception to a localized area of the body; prevents sensory info from peripheral nerves from reaching the CNS

Question 12

how does general anesthesia affect pain reception?

Answer 12

causes a complete loss of sensory perception

Question 13

what is the “wind-up” phenomenon?

Answer 13

an exaggerated pain response after going under anesthesia

*prevented by dosing pre-operative and post-operative pain medication
-speeds up recovery and increases immunity post-op

Question 14

what is proprioception?

Answer 14

knowing the location, position, and movement of body parts

*monitored by stretch receptors in limbs