piri somatosensation

Question 1

what are the nonencapsulated types of receptors

Answer 1

nociceptors and pain receptors

Question 2

pacinian

Answer 2

highly sensitive to vibration, located in the dermis, textures, fast adapting

Question 3

meissner

Answer 3

small receptor field, fast adapting, most common in glabrous skin, low frequency vibration/skin motion

Question 4

A beta receptors

Answer 4

transmit tactile information

Question 5

A alpha fibers

Question 6

A delta fibers

Answer 6

DOUBLE CHECK:initial fast transmission of pain (type 1 low threshold temperature and type 2 low threshold mechanical and chemical)
-myelinated fibers

Question 7

C fibers

Answer 7

responds to all pain, subtype preferences for heat, chemical etc
-unmyelinated

Question 8

what region of the cortex receives most somatosensory information

Answer 8

3b

Question 9

what is the medial lemniscus pathway and what information does it carry

Answer 9

-pseudunipolar somatosensory touch receptor cells go through the dorsal root ganglion and extend up the medial dorsal root column.
-in the medulla, these first order pseudounipolar cells synapse with the dorsal column nuclei.
-the second order dorsal column nuclei decussate in the midbrain and synapse in the VPL thalamus.
-VPL thalamus third order neurons terminate in the somatosensory cortex 1 and 2.

this pathway conveys tactile information about touch, pressure, vibration

Question 10

what is the spinothalamic/anterolateral pathway and what kind of information does in convey

Answer 10

-the spinothalamic pathway conveys information about nociception and temperature

-pseudounipolar ganglion cells from the periphery extend through the dorsal ganglion to the laminae 1/5. They decussate. Then these second order neurons project to the brainstem.
-From the brainstem, 3rd order extend to the thalamus.

Question 11

trigeminal pathway

Answer 11

-pseudounipolar neurons project from the periphery to the principal trigeminal nuclei
-second order neurons extend from the trigeminal nuclei to the ventral posterior medial nuclei of the thalamus. These decussate.
-third order neurons extend from the thalamus to the somatosensory cortex

-conveys tactile information about the face

Question 12

what cranial nerves travel along the trigeminal pathway

Answer 12

cranial nerves 7, 9, 10

Question 13

which section of the laminae receive both cutaneous and nociceptive (multimodal) information

Answer 13

laminae 5

Question 14

type 1 a delta fibers

Answer 14

respond to mechanical and chemical stimulation

Question 15

type 2 a delta fibers

Answer 15

respond to temperature stimulation

Question 16

where does integration in the somatosensory cortex take place

Answer 16

posterior parietal cortex,

Question 17

what is integrated in the somatosensory cortex

Answer 17

streams of somatic sensation information, visual stimuli, and movement planning

Question 18

gracile tract

Answer 18

axons of neurons which carry information about somatosensation in the lower body, gracile column nuclei located in the dorsal column nuclei

Question 19

cuneate tract

Answer 19

axons of neurons which carry information about somatosensation in the upper body, cuneate column nuclei located in the dorsal column nuclei

Question 20

what cranial nerve carries information about the face

Answer 20

nerve 10

Question 21

what happens as a result of a lesion to the PPC

Answer 21

agnosia (inability to recognize objects)

Question 22

phantom limb syndrome

Question 23

what are the components of inflammatory soup

Answer 23

bradykinin (depolarizes nociceptors), prostoglandins(increases sensitivity of nociceptors to other stimuli), substance P(causes the release of histimine), 5HT, H+

Question 24

hyperalgesia

Answer 24

release of too much inflammatory soup

Question 25

what is the importance of the descending somatosensory pathway

Answer 25

still unclear but mostly to regulate and refine the ascending pathways

Question 26

how do opioids work

Answer 26

they suppress the release of glutamate and also cause the inhibition of postsynaptic neurons in the spinothalamic pathway

Question 27

what is the visceral pain pathway

Answer 27

-peripheral first order pseudounipolar cells synapse with axons in the intermediate gray region of the spinal cord
-second order axons extend from the intermediate gray region near the gracile nuclei in the dorsal column
-third order neurons decussate along the medial lemniscus to the VPN in thalamus
-fourth order neurons extend from the thalamus to the insular cortex

the visceral pathway carries information about visceral (internal) pain

Question 28

what happens when you eat a hot pepper

Answer 28

capsaicin, a compound in peppers, acts as a ligand for the VR-1 temperature receptor
-this receptor is opened and the temperature sensitive cell is activated

Question 29

what fibers are cold receptors coupled with

Answer 29

a delta and c

Question 30

what fibers are hot receptors coupled with

Answer 30

c fibers