Neurohistology Flashcards Preview

Year 1 Neuroanatomy > Neurohistology > Flashcards

Flashcards in Neurohistology Deck (27):
1

what types of neurons are associated with sensory receptors?

bipolar and pseudounipolar neurons

2

where are bipolar neurons located?

olfactory epithelium, retina, vestibular apparatus, cochlea

3

where are type 1a / Aa fibers located?

myelinated fibers from annulospiral endings innervating muscle spindles

4

where are type 1b / Aa fibers located?

myelinated fibers innervating Golgi tendon organs

5

where are type 2 / AB fibers located?

myelinated fibers from flower spray endings innervating muscle spindles, cutaneous tactile receptors

6

what is the function of type 3 / Ad fibers?

lightly myelinated fibers that relay pain, temperature, crude touch sensations

7

what is the function of type 4 / C fibers?

unmyelinated fibers that relay pain and temperature sensations, and dull, poorly-localized pain

8

nociceptors use what types of fibers?

Ad (lightly myelinated) and C (unmyelinated)

9

mechanosensitive nociceptors use what type of fibers?

terminals of Ad fibers

10

thermosensitive nociceptors use what type of fibers?

terminals of Ad fibers

11

polymodal nociceptors use what type of fibers?

terminals of C fibers

12

cold receptors use what type of fibers?

free nerve endings of Ad fibers

13

warmth receptors use what type of fibers?

free nerve endings of C fibers

14

where are Meissner's corpuscles located?

dermal papillae

15

where are Pacinian corpuscles located? what is their stimulus?

1. deep dermis, hypodermis, ligaments, IO membranes, external genitalia, joint capsules, pancreas 2. pressure, vibration, tickling

16

where are Ruffini end organs located? what is their stimulus?

1. joint capsules, dermis, hypodermis of hairy skin 2. proprioceptive input

17

extrafusal muscle fibers receive motor innervation from what type of neurons?

alpha motor neurons and pseudounipolar neurons

18

what type of mechanoreceptor monitors muscle length?

muscle spindle

19

static nuclear bag fibers are sensitive to what parameter?

changes in muscle length

20

dynamic nuclear bag fibers are sensitive to what parameter?

rate of change in muscle length

21

nuclear chain fibers are mostly sensitive to what parameter?

changes in muscle length

22

when are annulospiral (primary) endings activated? what type of neuron provides the sensory innervation?

1. onset of muscle stretch or tension 2. type 1a

23

when are flower spray (secondary) endings activated? what type of neuron provides the sensory innervation?

1. when stretch is in progress 2. type 2

24

what provides motor innervation to intrafusal fibers?

gamma motor neurons

25

GTOs receives sensory innervation via what type of neuron?

type 1b

26

what it the function of GTOs?

monitor the amount of tension placed on a skeletal muscle

27

what are the histological changes that occur during CNS degeneration?

1. microglia clean up debris 2. no basal lamina or Schwann cell guidling tunnels present in CNS 3. oligodendrocytes release an inhibiting factor 4. astrocytes may not release enough GF 5. astrocytic scar tissue replaces damaged tissue