Brainscape's Knowledge GenomeTM

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


See full index

Year 2 - Committe 2 - Histology > Nerve Tissue > Flashcards

Nerve Tissue Flashcards

1
Q

What dose the nerve tissue control ?

A

It controls and integrates the functional activities of the organs and organ systems

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

What are the three basic functions of the nerve tissue ?

A

1.sensing changes with sensory receptors
2.interpreting and remembering those changes
3.reacting to those changes with effectors

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

What dose the central nervous system (CNS) contain ?

A

• Brain (cerebrum)
• Cerebellum
• Spinal cord (Medulla Spinalis)

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

What dose the peripheral nervous system (PSS) contain ?

A

• Ganglions :
➢ Autonomic (sympathetic and
parasympathetic) ganglia
➢ Dorsal root (spinal or sensory) ganglia
• Nerves
➢ Cranial nerves (those emerge from
brain)
➢ Spinal nerves (those emerge from
spinal cord)
• Nerve endings

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

How is the nervous system formed ?

A

Formed by a network of many billion nerve cells(neurons) and many more supporting cells called glial cells.

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

How is the nervous tissue distributed ?

A

Nerve tissue is distributed throughout the body as an integrated communications network.

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

What are the two types of cells that is found in both central and peripheral nerve tissue ?

A

1- Neurons
2- Glial cells

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

What are the features of the nerve tissue ?

A
  • Nervous tissue contains nerve cells
    (neurons), neuroglia cells and very
    few connective tissues.
  • Nerve cells are separated from
    connective tissue by a wall called
    blood brain barrier.
  • Nerve cells do not exhibit
    mitosis(non-divided). Neuroglia
    cells exhibit mitotic activity.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the origin of the nerve tissue cells ?

A

CNS neurons and central glia, except microglial cells, are derived from
neuroectodermal cells of the neural tube.
• microglia cells are derived from mesodermal macrophage precursors, specifically
from Granulocyte/monocyte progenitor (GMP) cells in bone marrow.
• PNS ganglion cells and peripheral glia are derived from the neural crest.

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

What dose the cell body ( perikaryon, soma ) of the neuron contain ?

A

Nucleus and cytoplasm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What dose the projections of the neuron contain ?

A

a. Dendrites : Multiple, receives stimuli
b. Axon : Single, conducts impulses away

➢ Synaptic boutons are small swellings that are found at the terminal ends of axons.

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

What is the cell body ( perykarion ) of the neuron ?

A

It is the dilated region of the neuron that contains a large, euchromatic nucleus with a prominent nucleolus and surrounding perinuclear cytoplasm.

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

What dose the perinuclear cytoplasm contain ?

A

abundant rough-surfaced endoplasmic reticulum and free ribosomes. On light microscopy, the rough endoplasmic reticulum with rosettes of free ribosomes appears as small bodies, called Nissl bodies.

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

Where are Nissl bodies rarely in?

A

Dendrites

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

Where is nissl bodies is not found in ?

A

The axon

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

What is the axon hillock ?

A

The area where the axon exits the trunk, the area where the action potential begins.

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

How dose dendrites work ?

A

receive information from other neurons at specialized areas of contact called synapses.

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

What are dendrites ?

A

They are projections that branch many times, forming small, tree-shaped structures protruding from the cell body that provide locations for other neurons to communicate with the cell body.

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

What are dendrites ?

A

They are projections that branch many times, forming small, tree-shaped structures protruding from the cell body that provide locations for other neurons to communicate with the cell body.

20
Q

How dose information flow through a neuron ?

A

from the dendrites, across the cell body, and
down the axon.

21
Q

Where is the axon in the cell body ?

A

a single thin process, much longer than the
dendrites, Its thickness is directly related to conduction velocity, which increases with axonal
diameter.
The portion of the axon between the cell body and the beginning of the myelin sheath is the initial segment., The axonal cytoplasm is called axoplasm

22
Q

What are the three sheets of the axon ?

A

• Axolemma; continuation of neuron cell
m e m b r a n e
• Myeline sheet; covers the axon (In the CNS)
* Neurolemma (Neurilemma); at the outside
of myelin sheet when the nerve enters PNS.
• Near the distal end of axon
1. Myeline sheet disappears
2. Neurolemma disappears
3. Axon ends surrounded only with axolemma

23
Q

How are neurons classified according to the number of their processes ?

A

• Multipolar neurons ( majority )
• Bipolar neurons ( special sensory organs like cohlear, vestibular, ganglions, retina and olfactory mucosa )
• Pseudounipolar neurons
• Unipolar and apolar neurons
• Anaxonic neurons

24
Q

What are the three types of neurons according to the number of extensions radiating from their bodies ?

A

• 1-Multipolar neurons: 1 axon
-2 or more dendrites
• 2-Bipolar neuron: 1 axon,
-1 dendrite: located in taste, smell, hearing and vision organs
• 3-Unipolar (pseudounipolar neuron):
-1 axon divided into 2: found in sensory neurons

25
Q

What are synapses ?

A

They are specialized junctions between neurons that facilitate the transmission of impulses from one (presynaptic) neuron to another (postsynaptic) neuron.

26
Q

How are Synapses between neurons may be classified morphologically ?

A

• axodendritic, occurring between axons and dendrites;
• axosomatic, occurring between axons and the cell body; or
• axoaxonic, occurring between axons and axons

27
Q

How are synapses are classified ?

A

• Chemical synapses: Conduction of impulses is achieved by the release of chemical substances (neurotransmitters) from the presynaptic neuron.
• Electrical synapses: Common in invertebrates, these synapses contain gap junctions that permit movement of ions between cells and consequently permit the direct spread of electrical current from one cell to another

28
Q

How are synapses are classified ?

A

• Chemical synapses: Conduction of impulses is achieved by the release of chemical substances (neurotransmitters) from the presynaptic neuron.
• Electrical synapses: Common in invertebrates, these synapses contain gap junctions that permit movement of ions between cells and consequently permit the direct spread of electrical current from one cell to another

29
Q

What are glial cells ?

A

They Support neuronal survival and activities and are 10 times more abundant than neurons in the mammalian brain.

30
Q

How many kinds of gilal cells are there ?

A

There are six major kinds of glial cells, four in the CNS and two in the PNS.

31
Q

What are the 5 functions of neuroglia cells ?

A

• Provides support and protection to neurons
• Myelination
• Repairing neuron damage
• Regulating the CSF (cerebrospinal fluid) content of the CNS
• To ensure metabolic transmission and exchange between vessels and neurons

32
Q

Where are schwann cells ?

A

They Envelop nerve fibers in the peripheral nervous
system.

33
Q

What dose schwann cells produce ?

A

They produce a myelin sheath.

34
Q

What dose schwann cells assist in ?

A

The regeneration of damaged fibers

35
Q

What dose the schwann cells allow ?

A

for faster action potential propagation along an axon in the PNS.

36
Q

What is the type of satellite cell in the neurons and what are there functions ?

A

Cuboidal or squamous glial cells of ganglia arranged around the cell bodies of neurons, their Function is metabolic and mechanical support to ganglia cells.

37
Q

What are the main components of the PNS ?

A

Nerves, ganglia and nerve endings.

38
Q

What are peripheral nerves ?

A

They are bundles of nerve fibers (axons) individually surrounded by Schwann cells and connective tissue.

39
Q

What are nerve fibers ?

A

A nerve fiber is the basic structural and functional unit of peripheral nerves, As axons course through body tissues, they are associated with Schwann
cells, The axon with its associated Schwann cells forms a nerve fiber.

40
Q

What is the myelin sheath ?

A

The myelin sheath is a spiral layer of insulation around a nerve fiber, Myelin is a large lipoprotein complex, its composition is like that of plasma membranes in general, 20% protein and 80% lipid (phospholipids, glycolipids, and cholesterol)

41
Q

Where is the myelination in the PNS ?

A

• Myelinated axons: Schwann cells wrapping repeatedly around an axon to form the multilayered myelin sheath.
• Unmyelinated axons: Several unmyelinated axons wrapping by one cytoplasm of schwann cell.

42
Q

What happens when one Schwann cell can
myelinate only one axon ?

A

several unmyelinated axons can be enveloped by a one Schwann cell.

43
Q

How are PNS axons myelinated ?

A

Schwann cell engulfs one portion along the length of a large diameter axon, Schwann cell membrane fuses around the axon and one thin extension of schwann cell elongates greatly and wraps itself repeatedly around the axon to form multiple compacted layers (myelin sheat).

44
Q

How is the nerve fibers and myelin sheath examined ?

A

• With vital staining (e.g. Methylene blue) axon appears blue and in silver impregnation blackish.
•These are the main methods to demonstrate myelinated fibers besides special immunohistochemical techniques.
• Weigert’s method and osmium stains myelin coat black
• Klüver-Barrera and Luxol-fast blue techniques stain myelin blue-green

45
Q

What is the schmidt - lanterman ( myelin cleft ) ?

A

The axon enveloped by the myelin sheat,which, in addition to membrane, contains some Schwann cell cytoplasm in spaces called Schmidt - Lanterman (myelin cleft) between the major dense lines of membranes.

Year 2 - Committe 2 - Histology (2 decks)

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