chapter 10

Question 1

what are sensory neurons

Answer 1

Sensory neurons have an end to receive sensory stimuli and produce the nerve impulse and the other delivers impulse to synapse in the CNS. The cell body is located in the middle

Question 2

Sensory receptors are specialized cells that generate graded potentials called _____ ______ in response to a stimulus.

Answer 2

receptor potentials

• Stimulus_: energy or chemical activating a sensory receptor
• Modalities (types of senses) arise from different receptors, each sensory neuron is specific to a sensation
• In other words, it’s all action potentials but pathways, synapses and the brain work to aid in interpretation

Question 3

Mechanoreceptors

Answer 3

mechanical deformation

Question 4

thermoreceptors

Answer 4

heat and cold

Question 5

photoreceptors

Answer 5

light

Question 6

chemoreceptors

Answer 6

chemical composition

Question 7

nociceptors

Answer 7

pain

Question 8

stimulus strength

Answer 8

increasing the frequency of AP

Question 9

adaptation

Answer 9

a decrease in receptors sensitivity

Question 10

phasic receptos

Answer 10

respond quickly but just as quickly adapt to stimulus

Question 11

tonic receptor

Answer 11

maintain response to stimulus

Question 12

area stimulated is called the

Answer 12

receptor field; changes the firing rate of a neuron

Question 13

characteristics of a receptor field

Answer 13

• size of receptor field depends on the density of receptors
• the more receptors, the smaller the receptive filed (fingertips), the larger the area of the somatosensory cortex
• a small receptive field=greater tactile acuity: sharpness of the sensation
• large receptive fields mean fewer receptors (Back)

Question 14

Lateral inhibition

Answer 14

-enhances the contrast between the center and periphery of a stimulated region, thereby increasing the brain’s ability to localize a sensory input.

• Receptors in the central area are stimulated more than neighboring receptors
• Receptors that are most strongly stimulated inhibit those around them.

Question 15

another phrase for lateral inhibition

Answer 15

sharpening of sensation

Question 16

the sharpening of sensation or lateral inhibition-reduces input from neighboring sensory neurons

Answer 16

true; you can pinpoint the sensation more accurately?

Question 17

Mechanoreceptors in skin

Answer 17

• Respond to touch and pressure
• Some have large receptive fields
• ->ex. Palm of your hand
• Others have small well-defined receptive fields
• ->ex. fingertips

Question 18

Thermoreceptors !

Answer 18

• Respond to thermal cues, Some chemicals can open channels as well
• More receptors for cold (located close to surface) than warm

Question 19

Nociceptors!

Answer 19

Respond to intense mechanical deformation, extreme temps and chemicals
-pain

Question 20

transient receptor potential channels

Answer 20

Painful heat or painful cold stimulates a whole different set of channels to open in the membrane called: transient receptor potential channels

Question 21

Referred pain

Answer 21

• Occurs due to both visceral and somatic afferent neurons converging on the same neurons in the spinal cord.
• Brain refers to somatic source
• Common areas of pain felt even though pain is in an internal organ

Question 22

How is pain different from other sensory information?

Answer 22

-After initial AP: changes can occur that may increase of decrease sensitivity to pain
-Pain can last after original stimulus is gone
-Pain can be altered by past experiences,
Emotions and simultaneous activations of
Other senses
EX: phantom limb
-Pain reduction depends mainly on endogenous
Opioids