Neurophys part 2

Question 1

Type of stimulus that activates merkel and ruffini

Answer 1

Steady pressure

Question 2

Type of stimulus that activates meissner and pacinian

Answer 2

vibration, which causes tingling sensation

Question 3

location of meissner and merkel

Answer 3

epidermis

Question 4

location of pacinian and ruffini

Answer 4

dermis

Question 5

Sensitivity of meissner and merkel

Answer 5

sensitive- activate with smaller stimuli

Question 6

Sensitivity of pacinian and ruffini

Answer 6

lower sensitivity, activate with more stimuli

Question 7

precision of meissner and merkel

Answer 7

more precise, smaller receptive field

Question 8

Precision of pacinian and ruffini

Answer 8

less precise, larger receptive field

Question 9

Which receptors are tonic/phasic

Answer 9

Tonic: merkel and ruffini (continued sensation like pressure/vibration)
Phasic: meissner and pacinian(rapdily adapt- wearing clothes)

Question 10

How does the brain know the difference between light and hard touch

Answer 10

AP frequency increases with harder and stronger touch

Question 11

What are mechanical nocioceptors stimulated by

Answer 11

sharp and high pressure

Question 12

What are chemical nocioceptors stimulated by

Answer 12

H+ ions, bradykinins

Question 13

What are thermal nocioceptors stimulated by

Answer 13

cold: <20C
hot: >40C

Question 14

What are fast pain nocioceptors stimulated by and what neurotransmitter is involved

Answer 14

a gamma fibers, glutamate

Question 15

What are slow pain nocioceptors stimulated by and what neurotransmitter is involved

Answer 15

chronic pain- c fibers
glutamate and substance p

Question 16

What is hyperalgesia

Answer 16

Increased pain from a normally painful stimuli (I.e. piniching is normally painful, but even more painful abnormally so)

Question 17

What is allodynia

Answer 17

Pain from a sitmulus that doesnt usually cause pain (i.e. touching skin over broken bone- touching doesn’t usually cause pain, but does)

Question 18

What cells do injured cells release

Answer 18

Prostaglandins, 5-HT, K, bradykinin, histamine

Question 19

What is the pain-spasm cycle

Answer 19

first tissue damage leads to pain, pain leads to muscle spasm, spasm causes more pain, more pain causes more spasm

Question 20

What is visceral/deep pain?

Answer 20

Very excruciating, diffuse, not localized, due to organ damage usually. C fiber driven

Question 21

What is referred pain?

Answer 21

Shared secondary neuron, brain interprets pain from wrong region

Question 22

What is phantom limb pain?

Answer 22

Regions of thalamus that once recieved input from amputated limb recieves input from stump, but brain interprets it as limb
- Remapping can occur- pain from amputated limb ends up elsewhere (i.e. face)

Question 23

What type of pain does convergence theory relate to

Answer 23

referred pain

Question 24

What is a form of automatic splinting

Answer 24

pain that leads to a muscle spasm (connected to pain-spasm cycle, where tissue damage leads to pain and then to muscle spasm, which is a form of automatic splinting)

Question 25

What is the primary sensory processing part of the brain

Answer 25

parietal lobe

Question 26

What is the size of the sensory processing region in the brain related to

Answer 26

1.the number of receptors and neurons in the region. - That dictates the sensitivity of an area on the body.

Question 27

What effects do opoids have on the neurons in the spinal cord (dorsal root ganglion)

Answer 27

1. Decrease Ca influx, lead to NT release 2. Hyperpolarizing membrane of spinothalamic tract neuron by increasing K+ efflux

Question 28

What is gate theory of pain?

Answer 28

If Large nerve fibers are strongly stimulated, these are passed to the brain over weaker signals from small nerves (like pain nerves) Opioid actions in spinal cord inhibit ascending pain signals

Question 29

what is the pathway for olfactory sensing

Answer 29

odarant binds to receptor, activates G-protein, activate adneyl cyclase, activate cAMP, open Na/Ca channel--> depoarization (smell!)

Question 30

Where do you get conscious descrimination of smells

Answer 30

orbitofrontal cortex

Question 31

Where are smells connected to emotions

Answer 31

amygdala

Question 32

Where are smells connected to memories

Answer 32

entorhinal cortex

Question 33

Where are smells connected to pheromones

Answer 33

vomeronasal organ

Question 34

Where are taste buds/how many

Answer 34

5000, on papillae, soft palate, epiglottis, pharynx

Question 35

What are tastants and how do we sense them

Answer 35

dissolve in saliva, then into pore, then onto microvilli receptors

Question 36

Simple gustatory pathway

Answer 36

Cn 7 (facial nerve) (anterior 2/3 of tongue), CN 9 (glosopharyngeal n )(posterior 1/3 tongue), CN 10 vagus (all the other places) --> medulla--> thalamus-->gustatory cortex

Question 37

Which tastes use metabotropic receptors

Answer 37

sweet, bitter, umami

Question 38

Which tastes use ionotropic receptors

Answer 38

salty, sour

Question 39

Which tastes are we most sensitive to

Answer 39

bitter tastes

Question 40

How does pupilary constriction occur

Answer 40

via parasympathetic activation - CN 3 (occulomotor) contracts sphinctor muscle

Question 41

How does pupilary dialation occur

Answer 41

inactivate CN3 (occulomotor)- relaxes pupilary sphinctor m

Question 42

Where are cones of retina located

Answer 42

fovea centralis of retina- directly behind pupil- where we want focal point of light to hit retina-

Question 43

Where is the blind spot in the eye

Answer 43

point where optic nerve (2) leaves eye- no photoreceptors

Question 44

Where are rods in the eye

Answer 44

periphery/sides of eyeball, low resolution

Question 45

What kind of fluid does anterior chamber hold

Answer 45

aqueous humor

Question 46

What secretes aqueous humor

Answer 46

cilliary processes

Question 47

What is the pathophys of glaucoma

Answer 47

interference of reabsorbtion of aqueous humor--> increased intraocular pressure--> potential damage to retina/optic nerve