unit 6 pt 2

Question 1

Type A𝛽 (A-beta) fibers

Answer 1

Large diameter myelinated neurons (fast conductance)

Carry sensory information for cutaneous mechanical stimuli.

Question 2

Type A𝛿 (A-delta) fibers:

Answer 2

Small myelinated neurons

Carry sensory information for cold, fast pain (nociceptors)

Question 3

Type C fibers

Answer 3

Small diameter, unmyelinated neurons (slow conductance)

Carry sensory information for slow pain (nociceptors)

Question 4

Mechanoreception (what, where, how is it stimulated)

Answer 4

most abundant receptor type
touch, pressure/stretch

Mostly found in skin and in some internal organs

Stimulated by different types of physical contact/deformation
-Stretch
- Steady pressure
- Fluttering/stroking movements
- Vibrations

Question 5

where does Mechanoreception occur

Answer 5

occurs through opening of mechanically gated ion channels.

Question 6

Deformation of the receptor membrane in response to the stimulus opens the ion channel
and allows

Answer 6

ions (usually Na+) to move into or out of the receptor cell causing a graded potential.

Question 7

Thermoreception (what, contains?)

Answer 7

temperature

are free nerve endings in the skin,
liver, skeletal muscles, and hypothalamus

transient receptor potential (TRP) channels. These can be classified as cold receptors and warm/heat receptors

depends on trp

Question 8

Thermoreception: which channels open/close when cold

Answer 8

open Na+ and Ca++

close K+ leakage channels, which
would also lead to a depolarizing graded potential

Question 9

how are Thermoreceptors stimulated by chemicals

Answer 9

mint = cold
chilly= hot
signal transduction is likely to occur via GPCR second messenger pathways.

Question 10

Nociception

Answer 10

pain/itch

Free nerve ending in the skin, muscles, joints, bones and some internal organs (viscera)

Question 11

what lacks Nociception

Answer 11

cns
brain can perceive pain anywhere in body except itself

Question 12

how is Nociception activated

Answer 12

Activated by strong noxious (harmful) stimuli that may damage tissue.

ex: extremely cold/hot temps, extreme pressure

Question 13

Nociception: slow vs fast pain

Answer 13

fast:
transmits rapidly to CNS through type A𝛿 fibers
ex: stubbing toe
slow:
transmits more slowly to CNS through type C fibers
ex: pain after stubbing toe

Question 14

Olfaction

Answer 14

Form of chemoreception

bipolar neurons in the roof of the nasal cavity.

These synapse with secondary neurons in the olfactory bulb

Question 15

Olfactory in limbic system

Answer 15

smell can be linked to
emotions/memory

Question 16

For olfaction- If the stimulus is strong enough and the
graded potential large enough

Answer 16

an action
potential occurs on the axon of the olfactory receptor, which will release neurotransmitter
onto the secondary sensory neuron in the olfactory bulb

Question 17

Gustation form of and linked to… what does it include

Answer 17

chemoreception, olfaction

Taste buds are composed of up to 150 taste receptor cells TRCs.
TRCs regenerate themselves ~
every 10-14 days

Question 18

Gustation: The different taste sensations use

Answer 18

different signal transduction pathways

Sweet, bitter, and umami use GPCR second messenger pathways that activate a G-protein
called gustducin