Neurohistology DOCX

Question 1

Receptor’s receptive field

Answer 1

Area territory where receptor resides & where it transduce a stimulus

Question 2

Sensory transduction

Answer 2

Transformation conversion of a stimulus to a receptor potential

Question 3

Receptor potential

Answer 3

generated following stimulation of a receptor

Question 4

Action potential

Answer 4

Nerve impulse propagated down the axon of a neuron.

Question 5

Type Ia or Aa

Answer 5

Myelinated fibers spiral endings inn. muscle spindle (fast)

Question 6

Type Ib or Aa

Answer 6

Myelinated fiber inn. GTO (fast)

Question 7

Aa sensory p/w to cerebellum.

Answer 7

Relays position info at unconscious level. (fast)

Question 8

Aa DC p/w

Answer 8

Relays fine detailed touch, vibration, position & some crude touch to CONSCIOUSNESS.

Question 9

Type II or Abeta

Answer 9

Myelinated fiber flower endings inn. muscle spindles, cutaneous tactile receptors (2nd fast)

Question 10

Type III or Ad

Answer 10

Lightly Myelinated, relay pain & temp & crude touch.
Sharp pain, well localized.

Question 11

Type IV or C

Answer 11

unmyelinated the slowest. Relays pain & temp.

Dull pain, poorly localized.

Question 12

Exteroceptors

Answer 12

Close to body, sensory stimuli.
Olfactory
Visual
Gustatory
Auditory
Tactile
Temperature

Question 13

Teloreceptors

Answer 13

Activated by distant stimuli
Light
Sound

Question 14

Contact Receptors

Answer 14

Contact required
Touch
Pressure
Pain
Temp
Chemicals

Question 15

Proprioceptors

Answer 15

Position of sense
Vestibular apparatus
Skin
Skeletal muscles
Tendons
Joint capsules
Static position
Kinesthetic position

Question 16

Interoceptors

Answer 16

Baroreceptors
Stretch
pH
CO2 or O2
Osmolarity

Question 17

Nociceptors

Answer 17

Respond to noxious stimuli.
Ad
C

Question 18

Mechanosensitive nociceptors

Answer 18

Terminal Ad

Respond to excessive mechanical stimuli and tissue injury

Question 19

Thermosensitive nociceptors

Answer 19

Terminal Ad

Respond to intense heat or cold

Question 20

Polymodal nociceptors

Answer 20

Terminal C fibers
Respond to various noxious stimuli.
Mech, temp & chem.

Question 21

Pruriceptors

Answer 21

Itch sensitive
C fibers
Respond to histamine

Question 22

Thermoreceptors

Answer 22

Ad & C

Respond directly to heat (C) & cold (Ad)

Question 23

Non encapsulated mechanoreceptors

Answer 23

Free nerve endings
Peritrichial
Tactile receptors

Question 24

Free nerve endings

Answer 24

Close to epidermis, cornea, teeth, mucous membranes, somatic structures.
Respond to touch, pressure, pain & temp
Simplest

Question 25

Tactile receptor

Answer 25

Abeta fiber
Merkels disc
Respond to fine detailed touch
(stereognosis)
In lower & upper epidermis

Question 26

Encapsulated mechanoreceptors

Answer 26

Meissner Corpuscles
Pacinian Corpuscles
Ruffini end organs
Muscle spindles
Golgi tendon organs

Question 27

Pacinian corpuscles

Answer 27

Deep dermis, hypodermis, ligaments, IOS membrane, external genitalia, joint capsules and pancreas
Stimulated by pressure, vibration & tickling

Question 28

Ruffini end organs

Answer 28

Joint capsules, dermis, hypodermis, of hairy skin

Proprioceptive input

Question 29

Extrafusal fibers

Answer 29

Typical skeletal muscle fibers.
Stimulation contracts them.
aMN inn.
sensory info from other.

Question 30

Muscle spindles

Answer 30

Specialized mechanoreceptors, unique to skeletal muscles. Monitors muscle length and velocity
Parallel to extrafusals
2 intralfusal, nuclear bag and chain

Question 31

Nuclear bag fibers

Answer 31

Non contractile
Skeletal muscle portion contractile 2 ends.
Static - change in length
Dynamic - changes in rate

Question 32

Nuclear chain fibers

Answer 32

Non contractile
Skeletal muscle contractile 2 polar ends
Changes in length

Question 33

Sensory innervation of muscle spindles

Answer 33

Via pseudounipolar neurons
Annulospiral Ia
Flower spray II

Question 34

Golgi tendon organ

Answer 34

Located where muscle insert at tendon
Arrange in series
No contractile portion
Sensory input via Ib
Measures amount of tension

Question 35

Regeneration in CNS

Answer 35

Axon severed
Microglia clean up
Axon sprouts
Scwhann cells & basal lamina guiding tunnel.
(oligo d, inhibit)
Astrocytes release GF but not enough.
SO scar is formed
Scar prevents sprout to reach target.
Minimal or no regenerations
Neurologic deficits are permanent.