Brainscape's Knowledge GenomeTM

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


See full index

Physiology > Exam II | Nervous System General Organization & Cytology > Flashcards

Exam II | Nervous System General Organization & Cytology Flashcards

1
Q

At what level of the spine does the spinal cord end?

A

L1-L2

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

At what level of the spine does the dura mater end?

A

mid-sacrum

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

What is the filum terminale? Where does it begin and end?

A
  • a specialized portion of the pia mater
  • filum terminale internum begins at medullary cone and extends through dural sac
  • filum terminale externum extends from bottom of dural sac to coccyx
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What does the white matter of the cord primarily consist of? Gray matter?

A
  • white consists of myelinated axons

- gray consists of cell bodies

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

What is the difference between tracts and nerves?

A

tracts are axon bundles in the CNS; nerves are axon bundles in the PNS

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

What are the buttons or ‘boutons’ of the neuron?

A

axon terminals

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

What are bipolar neurons, and where are they located?

A
  • sensory motor neurons
  • present in the eye and other specialized sensory structures
  • e.g hair cells of the cochlea
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are pseudo-unipolar neurons, and where are they located?

A
  • sensory motor neurons
  • free nerve endings (e.g. dendrites extend up into dermis) that act as the receptor
  • present in the somatosensory system
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are multipolar neurons?

A

motor neurons with a large number of dendrites

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

What are primary or alpha motor neurons, and where do they extend from?

A
  • aka lower motor neuron (LMN) or last neuron
  • the neuron that carries the final motor signal and is in contact with the effector (muscle)
  • extends from ventral horn of cord to effector
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are primary or alpha sensory neurons?

A
  • initial neuron in pathway the generates action potential
  • carries initial sensory signal
  • may also be the receptor cell (e.g. free nerve ending)
  • or it may receive signals from a specialized receptor (such as a Merkel’s disk or corpuscle)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Where is the cell body of the afferent nerve?

A

DRG or cranial nuclei

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

Where is the cell body of the efferent nerve?

A

the ventral horn of the cord or cranial nuclei

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

What does the term “somatic” refer to?

A
  • motor neurons of the PNS

- or to all motor and sensory neurons of the PNS that are not autonomic

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

Significance of dendritic spines

A

critical for interneuronal communication or LTP (learning, memory, association, etc.)

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

How many neurons and synapses form a disynaptic reflex arc?

A
  • 3 neurons (efferent, interneuron, afferent)

- 2 synapses

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

What is the difference between nervous system ganglia and nuclei?

A
  • Ganglia are in the PNS, nuclei are in the CNS

- exception is basal nuclei

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

How does a sensory ganglion differ from an autonomic ganglion?

A

autonomic ganglion have synapses, sensory ganglion do not

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

What is the difference between a motor unit and a myotome?

A
  • a motor unit is a motor NEURON and all the muscle FIBERS innervated by it
  • a myotome is a range of MUSCLES that are generally innervated by MORE THAN ONE spinal NERVE
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the neurotransmitter and receptor at the neuromuscular junction?

A

Ach; nicotinic

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

What is a motor endplate?

A
  • the neuromuscular junction

- a depression in myocyte (muscle fiber) membrane

22
Q

Give an example of a motor end plate (MEP) pathology

A

myasthenia gravis

23
Q

What are the glial cells of the CNS?

A
  • astrocytes
  • ependymal cells
  • microglia
  • oligodendrocytes
24
Q

What is a satellite sell?

A

supportive cells in sensory and autonomic ganglia analogous to astrocytes

25
Q

astrocytic processes

A
  • surround dendrites, nodes of Ranvier, synapses, and capillaries
  • form much of the structural framework of neuropil
26
Q

What is the glia limitans?

A

thick layer made up of interlocking astrocyte processes that surrounds brain and spinal cord

27
Q

How do astrocytes compare to neurons in the CNS in terms of size and abundance?

A
  • more astrocytes than neurons in the brain

- astrocytes are smaller than neurons

28
Q

Where do most brain tumors originate from?

A

astrocytes

29
Q

7 astrocyte functions

A

1) controls what passes from blood to neuron (nutrients, wastes)
2) contribute to structural integrity of BBB
3) maintain GABA, glutamate, and CNS ion (Na+ and K+) levels
4) involved in Ca2+ dependent exocytosis
5) developmentally induce formation of endothelial tight junctions
6) facilitate neuronal metabolism (mediate PO4- transfer
7) contribute to CNS healing after injury or degeneration

30
Q

What is gliosis?

A
  • Glial scar formation after injury to the central nervous system
  • astrocytes increase in number and release inflammatory cytokines following injury or degeneration
31
Q

What are the immune cells of the CNS? What is their mechanism of action?

A
  • microglia
  • they relocate to site of injury/infection, alter cell structure, and proliferate
  • phagocytic
  • release inflammatory cytokines
32
Q

What percent of brain cells are microganglia?

A

15%

33
Q

What is a ramified glial cell?

A
  • resting glial cell (not functioning as a macrophage)
  • soma is usually fixed with motile processes
  • typical of healthy CNS
34
Q

What causes dystrophic microglia?

A

deterioration of microglia is due to age-related processes

35
Q

What happens in reactive gliosis?

A
  • injury or infection becomes so severe that efforts of microglia to control it actually begin to promote it
  • -microglia hypertrophy due to acute injury
36
Q

What are ‘gitter’ cells?

A

activated microglia (macrophages) which have consumed as much as possible

37
Q

What is an activated microglia?

A
  • microglia that has turned into a macrophage

- cell acquires an amoeboid shape and becomes a pro-inflammatory, motile cell

38
Q

What are 2 demyelinating diseases of the CNS?

A
  • Leukodystrophies

- MS

39
Q

Do oligodendrocytes make up white or gray matter of CNS?

A
  • white matter

- although satellite oligodendrocytes are part of gray matter

40
Q

What is the majority of myelin made up of?

A

80% lipids

41
Q

How many neuronal fibers can an oligodendrocyte myelinate compared to a Schwann cell?

A
  • oligodendrocyte can contribute to myelination of up to 50

- Schwann cell just one

42
Q

By how much does saltatory conduction increase conduction speed?

A

10 fold

43
Q

What 4 signals trigger oligodendrocyte precursor cells (OPCs) to myelinate an axon?

A
  • ATP
  • glutamate
  • GABA
  • cell adhesion molecules
44
Q

What is the structure of ependymocytes and where are they found?

A
  • have microvilli and primary cilia on apical surfaces

- line central canal of cord and also portions of the ventricles

45
Q

Function of ependymocytes

A
  • produce CSF in choroid plexus
  • selectively secrete capillary filtrate into the ventricles
  • regulate flow of CSF with cilia
  • regulate levels of CSF with microvilli for absorption
  • remove waste products from CSF and adjust its composition over time
  • contribute to BBB
46
Q

How many times does a myelinating neurolemma wrap around an axon?

A

up to 100X

47
Q

What is a Remak bundle?

A
  • non-myelinating neurolemma that envelops several small fibers
  • does not necessarily increase the speed of conduction
48
Q

What is myelin made up of?

A

water and collagen

49
Q

What is a neurofibroma?

A

a tumor with multiple cell types, including Schwann cells, mast cells, and fibroblasts

50
Q

(From video) 3 approaches to getting CNS neurons to regenerate

A

1) Making environment around neurons favorable ( inhibiting CSPGs)
2) introducing factors that directly boost neuron’s capacity to heal itself (integrins, IGF, osteopontin)
3) Combination of 1 and 2 (mesenchymal stem cells)

51
Q

(From video) How can mesenchymal stem cells help with CNS axon regeneration?

A
  • naturally hone in on site of injury and protect against secondary damage caused by immune system
  • may promote axon regeneration and myelin repair
  • may directly transform into new neurons

Physiology (10 decks)

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