Neurohistology DOCX Flashcards Preview

Neuroanatomy I > Neurohistology DOCX > Flashcards

Flashcards in Neurohistology DOCX Deck (35):
1

Receptor's receptive field

Area territory where receptor resides & where it transduce a stimulus

2

Sensory transduction

Transformation conversion of a stimulus to a receptor potential

3

Receptor potential

generated following stimulation of a receptor

4

Action potential

Nerve impulse propagated down the axon of a neuron.

5

Type Ia or Aa

Myelinated fibers spiral endings inn. muscle spindle (fast)

6

Type Ib or Aa

Myelinated fiber inn. GTO (fast)

7

Aa sensory p/w to cerebellum.

Relays position info at unconscious level. (fast)

8

Aa DC p/w

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

9

Type II or Abeta

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

10

Type III or Ad

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

11

Type IV or C

unmyelinated the slowest. Relays pain & temp.
Dull pain, poorly localized.

12

Exteroceptors

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

13

Teloreceptors

Activated by distant stimuli
Light
Sound

14

Contact Receptors

Contact required
Touch
Pressure
Pain
Temp
Chemicals

15

Proprioceptors

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

16

Interoceptors

Baroreceptors
Stretch
pH
CO2 or O2
Osmolarity

17

Nociceptors

Respond to noxious stimuli.
Ad
C

18

Mechanosensitive nociceptors

Terminal Ad
Respond to excessive mechanical stimuli and tissue injury

19

Thermosensitive nociceptors

Terminal Ad
Respond to intense heat or cold

20

Polymodal nociceptors

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

21

Pruriceptors

Itch sensitive
C fibers
Respond to histamine

22

Thermoreceptors

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

23

Non encapsulated mechanoreceptors

Free nerve endings
Peritrichial
Tactile receptors

24

Free nerve endings

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

25

Tactile receptor

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

26

Encapsulated mechanoreceptors

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

27

Pacinian corpuscles

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

28

Ruffini end organs

Joint capsules, dermis, hypodermis, of hairy skin
Proprioceptive input

29

Extrafusal fibers

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

30

Muscle spindles

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

31

Nuclear bag fibers

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

32

Nuclear chain fibers

Non contractile
Skeletal muscle contractile 2 polar ends
Changes in length

33

Sensory innervation of muscle spindles

Via pseudounipolar neurons
Annulospiral Ia
Flower spray II

34

Golgi tendon organ

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

35

Regeneration in CNS

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.