Review of Cellular Neuroanatomy Flashcards Preview

Clinical Neuroscience weeks 1-3 > Review of Cellular Neuroanatomy > Flashcards

Flashcards in Review of Cellular Neuroanatomy Deck (58):
1

What are glia

They provide physical support to neurons (the other of the two principal cell types in the nervous system).
Also provide electrical insulation for impulse conductance
Provide metabolic exchange between the the vascular system and the Nervous sytem

2

Cell Body of a Neuron called?

Soma

3

Name the two types of processes that extend from a soma?

Axon and Dendrites

4

Electrical input for the cell comes trhough?

Dendrites

5

Electrical output for a cell comes through

Axon

6

Gray Matter =

unmyelinated tissue

Primaruly somas and dendrites

7

White matter=

tissue containing myelinated axons

8

Myelin=

lipid wrapping on axons

9

Soma of Neurons is especially rich in what cell organelle?

rER...because of the large amount of proteins it produces

10

What stain is used to look for Neuronal somas and proximal dendrites

A Nissl stain

11

What is a Nissl stain

A stain which preferentially stains Nissl substance made up of Nissl bodies...basophillic mass that is made up primarily of rER and ribosomes (protein synthesis bundles).

12

Nissl stain typically stains what parts of a neuron?

Cell body (stroma) and proximal dendrites...does not extend into the axon

13

rER stacks appear as islands in the Nissl stain

ok

14

Axons usually form where?

the soma at the axon hillock specifically

15

What is the axon Hillock

An area that is free of cell organelles. The beginning of an axon.

16

Axonal initial segment is?

The area of the axon that originates at the hillock and goes to the beginning of the myelination line

17

What are dendritic spines?

Places where dendrites receive information from other Neurons via synapses. This is especially true for excitatory inputs

18

Which part of the axon is generally the site of action potential initiation?

Axonal initial segment

19

What are axon collaterals

major branches of an axon

20

Neurons whose axons contact muscle or glands are known as?

motor neurons

21

Neurons are classified based on what?

Dendritic structure (number and pattern of dendrites)

22

What are principal cells

Projection neurons, meaning they integrate information and send axons to other brain areas.

23

Golgi Type 1 cells are

Principal cells...just means they have a long projection axon

24

Interneurons are

cells that do not send their axon out of the local brain area. Also called local circuit neurons

25

Interneurons are also classified as

Golgi Type 2 cells

26

Synapses are

specialized junctions that allow neural signals to be communicated from one cell to another

27

Two types of synaptic transmissions and they are?

Chemical and Electrical

28

Electrical synapses are formed as direct connections from one cell to another via gap junctions.

ok

29

Chemical synapses = electrical signal in the presynaptic neuron is transduced into release of a chemical transmitter that traverses a synaptic cleft to bind to receptors on the postsynaptic neuron

ok

30

Synapses classified how?

By their subcellular target (axosomatic - synapse between axon and soma)

31

Most excitatory synapses are what

formed on dendritic spines...called axospinous

32

Vertebrate chemical synapses are

Unidirectional...they only transmit info from the presynaptic neuron to the postsynaptic

33

Know the pattern of sending a signal via a synapse

1) The presynaptic bouton contains membranous synaptic vesicles that contain neurotransmitter

2) On an incoming nerve impulse, the entry of calcium causes synaptic vesicles to release their contents into the synaptic cleft

3) Specialized receptor proteins located in the postsynaptic density bind the neurotransmitter and generate another electrical signal in the postsynaptic cell.

34

On the basis of their function, neurotransmitters can be divided into three classes:

excitatory- these types of synapses increases the probability that the postsynaptic neuron will fire an action potential. Examples are synapses containing acetylcholine ( at nicotinic receptors) or glutamate

inhibitory- reduces the probability that the postsynaptic neuron will fire an action potential. Examples are synapses with glycine or GABA

modulatory - influences how excitatory and inhibitory signals are integrated.

35

Excitatory means

Inhibitory means

something that increases the probability of an action potential

Inhibitory means something that decreases the probability for an action potential

36

Gray's type 1 synapse

Excitatory

37

Gray's type 2 synapse

Inhibitory

38

Gray's type 1 synapses (excitatory) are found mostly on what?

Dendrites

39

Type II synapses (inhibitory) are found where?

Somas mostly

40

In electrical synapses, passive flow of electrical current from one cell to the next is achieved via?

Gap junctions

41

Gap junctions are made up of what

Connexons (6 connexins make a connexon). These pores form a connection between the cytoplasm of two opposing cells

42

ELectrical synapses can be bi-directional

whereas chemical synapses are uni-directional

43

How are proteins made in the soma transported out of the soma and through processes (axons and dendrites)

- Packed into cargo vesicles and transported along microtubules toward their destination via ratchet-like action.
- Remember, there are separate engines for movement to the soma and away from the soma
- To the soma= Dynein...moves vesicles retrograde (to the soma)
- Away from the soma (anterograde)- Kinesin

44

Schwann cells do what?

Provide myelination in the PNS

45

Oligodendrocytes do what

myelination in the CNS

46

Astrocytes do what

Provide general support and serve as part of the blood brain barrier in the CNS.

47

Two types of astrocytes are?

Fibrous:
Protoplasmic

48

Microglia do what?

They mediate phagocytosis and response to inflammation in the CNS... The immune cells of the brain

49

Schwann cells, oligodendrocytes, astrocytes, and microglia are all what type of cells

Neuroglia----supporting cells

50

Schwann cells provide myelination in the PNS. Myelination does what

electrical insulation

51

Node of Ranvier is what?

The area in between two schwann cells...an unmyelinated area. This is the area where action potentials regenerate

52

Endoneurium

Thin connective tissue layer that surrounds each nerve fiber

53

Perineurium

Surrounds the nerve fascicle itself

54

One oligodendrocytes has several processes and each process myelinates one axon, therefore one oligodendrocyte myelinates several axons

know

55

Astrocytes do what

move metabolites to and from neurons

56

Perineural feet?

Perivascular feet

processes from astrocytes that make ocntact with neurons

processes from astrocytes that make contact with blood vessels and myelin

57

What are satellite cells

small cuboidal cells of neural crest origin....function as the astrocytes of teh PNS

58

Ependymal cells

Line the ventricles of the braina nd the central canal of the spinal cord...cells are often cilliated and form simple cuboidal or low columnar epithelium.