Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Histology Fall 2012 > Histo Neurohistology 11.26.12 > Flashcards

Histo Neurohistology 11.26.12 Flashcards

1
Q

what are the two plexuses of the Enteric NS

A

Meissner’s Plexus

Aurbach’s Plexus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is Messner’s Plexus

A

lies in submucosal CT and innervates gland cells int eh mucosa and submucosa and the muscularis mucosa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Auerbach’s Plexus

A

regualtes contractility of the outer muscle layers, which are involved in PERISTALSIS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What embryonic layer is CNS derived from?

A

Ectoderm!

Neuroectoder –> nerual plate –> sinks into underly myesoderm –> neural tube –> neural crest cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What does the neuroectoderm (neuroepithelium) differentiate into?

A

neurons, glia, ependyma that forms brain and spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What neural elemnts does neural crest give rise to?

A

Sensory neurons
of cranial and spinal sensory ganglia

Postganglionic neurons
of sympathetic and parasympathetic ganglia

Supporting cells of the PNS (shwann cells and satellite cells of ganglia)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What non-neural elemetns does neural crest give rise to?

A

Cells of the PIA MATER and ARACHNOID MATER

some BRANCHIAL CARTILAGE and some cranial mesenchyme

Pigment producing cells of skin and subcutaneous tissues (MELANOCYTES)

Chromaffin tissue (secretory cells of adrenal medulla)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What elements does CNS have that are derived from neural crest

A

central axons of DRG cells that enter the spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What elemnts does PNS contain that are derived from neuroepithelium

A

axons of motorneurons that enter spinal nerves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are two impt consequences of CNS Epithelial Origin?

A
  1. CNS contains NO CT (except fo hat ocntributed to invaginating blood vessels)
  2. CNS is surrounded by basal laminsa
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Differnece between CNS and PNS hisologically

A

PNS has CT
CNS has NO CT

incoming nerves have CT, white matter in spinal cord does not

Look for TRICHOME stain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What two types of cell commprise CNS

A

Neurons and GLia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Neurons

A

irritability and conductivity

erive form presence of an excitable membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is dynamic polarization of neurons

A

specialization of differnt parts of the cell into receptive sites, integrating sites, and impulse-initianting site, and impulse-conducting sites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Neuronal Cell Body

A

gnerally contains large and oviod or spehrical nuclues with euchormati chormatin; Barr bodies may be seen

Perinuclear cytoplasm has many ribosomes, esp within stacks of RER

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Nissl bodies

A

seen in soma,
stacks of RER
very basophilic, diffusely

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Does the axon hillock have Nissl substances?

A

no

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are prominent in nerons?

A

Golgi complex,

since Nueroanl cell bodies manufacture material (vesicles) for release by axon terminal

contain lysosomes;

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Lipfuscin granules

A

insoluble resides of lysosomal activity may accumulate to form Liofuscin ganuesl

esp visible in neurons of sympatheric and dorsal root ganglia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Wher eare Melanin grandules found?

A

within the brain in a region called SUbSTANTIA NIGRA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Neurofbirillary Stains

A

contain silver

turn structures of Cytoskelelal elemnts (MT and NF) ,
revveal shape of cell and its processess

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is a dendrite?

A

generally similar in fine structure to soma

most synaptic input onto nueron occurs onto its dendritic arbor

Dendrites may contain some Nisl substances (RER)

many NF and MT are present, running longitudinally

ORE VISIBLE IN SILVER_STAINED PREPS than by H&E

23
Q

What are axons?

A

emerge from axon hillock of the soma

most of voluem f neuron is contained within axon `

24
Q

how can you tell the difference betweeen axon and dendrites

A

Axons have NO ribosomes, b/c no protein synethesis

Axons cylinder is same diameter throughout its entire lenbht

Dendiites are thicker as they emerge form somae and get slowly narorwer

Neuron will NEVER have more than oaxon

25
Q

What are the two PNS supporting cells

A

Schwann cells
ensheath the axons of the peripheral nerve fibers

Satellite cells
encheath the cell bodies of neurons located in algnia

26
Q

How do all sensory information flowing in from body (Somatic and Visceral) flow in

A

All sensory information flowing in form teh body (somatic and visceral) , with the exception of special senses, is carried by fibers of PSEUDOUNIPOLAR neurosn and enters teh spinal cord via the dorsal roots

27
Q

Dorsal Root Ganglia

A

and sensory ganglia of some cranial nerves have pseudounipolar neurons

NEuorns are heterogeneous in size

28
Q

What size oare DRG and Snesory ganglia

A

heterogeneous in size

size of soma is roughly proportional to axon diamter, and this can vary widely, from very small unmeylinated to large myelinated

DRG neurons ahve NO dendirtes, and DRG contains no synapses

29
Q

What is the soma of EACH DRG neuron surrounded by>

A

single layer of small, flattneed cuboidal cells, the SATELLITE CELLS

each surrounded neuon is itslef surrounded by basal lamina and loos CT and whole ganglion is surrounded by a CT capsule that is continous with PERINEURIUM and EPINEURIUm of ass. nerve.

30
Q

does DRG contain lipofuscin granules

A

YES! OFten!

31
Q

Where are autonomic sympathetic ganglia located?

A

as swellings along the sympathetic chain.

32
Q

Where are autonomic PS ganglia present?

A

near, or wihtin teh walls of organs innervated by ANS

33
Q

what kind of neurons in ANS

A

more homogenous in size than DRGs (all sensory somatic or visceral)

unlike DRG, sympathetic ganglia are integrating centers with many synapses

34
Q

In dgestive system, where are enteric ganglia found?

A

in submucosa –> MEISSNER”S PLEXUS

and at eh interace b/w the tinner and outer layers of muscularis exerna (AUERBACH’s PLEXUS)

35
Q

Where is Meissner’s plexus found?

A

in submucosa

36
Q

wher eis Auerbach’s plexus found

A

at the interace b/w the inner and outer layers of hte uscularis externa

37
Q

What is a nerve?

A

cylindrical, flexible struture that contains axons, glia, ans ome fibroblasts

38
Q

Whwat are glia

A

Schwann cells

tey surround each axon whether it is myelinated or not

Schwann cells and gibroblasts both manufacure the CT that surrounds each axon

39
Q

Does every axon have a Schwann cell sheath in PNS?

A

yes!

40
Q

Difference between myeline covering in PNS and CNS

A

in PNS- one Schwann cell covers one internodal segment on oen axon

CNS- one oligodendrocyte covers one internodal segment of many (10-50 axons)

41
Q

What is the general structure of ALL PNS sheaths, meyelinated or unmyelinated?

A 
axon (innermost)
sheath (myelin or Schwann cell process)
Basal Lamina
CT layer 1 (Endoneurium (around each axon)
CT layer 2 (Perineurium)
CT 3 (Epineurium- outermost)
42
Q

What is endoneurium

A

lies arodn each individual myelinated axon or unmyelinated gouprs of axons

43
Q

Perineruium

A

lies around each budnle of axons and also surrounds the entire nerve

44
Q

Epineurium

A

loost CT fascia outisde the external perineurial sheath

Surrounds entire nerve and blnds in to surrounidng CT

All thes CT layers are formed by gibroblass n various latery

45
Q

Descirbe unmeylinated periehral axons

A

one Schwann cell wrpas a group of aoxons

one Schwann cell may invest as mnay as 20 unmyelinated axons

Sheath of unmeylinated aoxn does not have nodes of Ranvier, as does a myelin sheath

Basal lamina surrounds the whole axon+ sheath complex

46
Q

What does PNSaxon look in H&E staining

A

dissovled lipid of myelin

leaving only ppt netowrk of protein (called neurokeratin, but nrelated to keratins)

Nerves look moth-eaten and ragged

47
Q

Osmium

A

myelin lipid is retained and stains very darkly, while aoxon itself is unstained;

48
Q

Silver stains the cytoskelton, so axon cylinder is vivisle while myelin is not

A

yep

49
Q

Are peripheral nerves mixed nerves?

A

yes!

contain many diff sizes nad degrees of myelination

50
Q

Fiber group A- heavily myelinated

A

high velocity, acute pina, temp, touch pressure prorprioception (fine touch fast)

51
Q

TYpe B fibers

A

less heavily myelinated

Moderate-volecity fibers, visceral fferents, pre-galncilinc autonimcis

52
Q

Type C fibers

A

slow velocity fibers postgaglionic autonomic, chronic pain

53
Q

Neurovascular budnle

A

nerves accompany artery, vein, and lymphatic fvessel as they run through CT of body

Histology Fall 2012 (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions