Neurons and Glia Flashcards Preview

Physiology > Neurons and Glia > Flashcards

Flashcards in Neurons and Glia Deck (56):
1

What two things are composed of neurons and glia?

The brain and the spinal chord

2

What is the function of neurons?

Processing information and conducting electrical impusles

3

What is function of glia?

Mechanical and metabolic support

4

What 3 things makes up the neuron?

1. Dendrites
2. Cell body (soma)
3. Axon

5

What are dendrites?

Recieve information from other neurons (the input part of the neuron)

6

What is the axon?

Conveys information to other nerve cells (the output part of the neuron)

7

How many axons do neurons normally have?

Just one that emerges from the cell body

8

What are the dendrites and axons sometimes collectively known?

Neurites

9

What two things make up the cell body?

The nucleus and the cytoplasm (perikaryon)

10

What is different between the nucleus in a neuron as compared to another cell?

Adult neurons do not replicate and the DNA is only involved in protein synthesis (it a blueprint for construction of neuronal components)

11

What manufactures the ribosomes of the neurons?

The nucleolus

12

The combination of ER and ribosomes is called the rough ER; what else can they be called?

Nissl bodies (seen by nissl staining)

13

Where are microtubules found in the neruon and what are they responsible for?

The dendrites, cell body and axon and are responsible for transporting packaged proteins

14

What else are the microtubules involved in that provides support for the neruon?

The form the cytoskeleton

15

What are lipofucin bodies in neurons?

The scrap yard of the neuron which contains the waste products of the old cells

16

What cellular components have a similar function in neurons as they do in normal cells?

Ribosomes, the golgi apparatus, mitochondria and lysosomes

17

What do the dendrites mainly contain in terms of cellular components?

Mitochondria and free ribosomes

18

What the connections with other neurons formed in the dendrites known as?

Synapses

19

What specialised structures of the dendrites and the synapses usually made on?

Spines

20

What are the four parts of the axon?

1. The axon hillock
2. The axon proper
3. Axon collaterals
4. The axon terminals

21

What the axon hillock?

The part of the axon that emerges from the cell body and contains lots of voltage gated ion channels to generate action potentials

22

What is the axon proper?

The main part of the axon

23

What is the axon collaterals?

The branches of the axon that go off to numerous locations

24

What is the axon terminals?

Swellings (boutons) that form synpases

25

Why is important that axons have a transport for proteins?

Because they dont contain ribosomes to make their own proteins

26

How does transport to the axon occur and what is this known as?

Along microtubules in axoplasmic transport

27

How fast is axoplasmic transport?

Very fast - 1000mm/day

28

What is axoplasmic transport towards the cell body called?

Retrograde transport

29

What is axoplasmic transport away from the cell body called?

Anterograde transport

30

Why would retrograde transport be useful?

To get rid of waste products back to the soma for them to be broken down

31

What are the 5 ways to classify neurons?

1. Number of neurites
2. Shape
3. Connections
4. Axons
5. Neurotransmitters

32

What are the three types of neurons classified under number of neurites?

Unipolar, bipolar and multipolar

33

What is an example of a unipolar neuron?

Sensory neurons

34

What is an example of a bipolar neuron?

That ones connecting the rods and cones in the eyes to the brain

35

What kind of shapes can neurons have?

Pyramidal, stellate

36

What 3 types of neurons are there in the classification based on connections?

1. Primary sensory neurons
2. Motoneurons
3. Interneurons

37

What are primary sensory neurons?

Neurons that form connection with sensory surfaces (skin, retina etc)

38

What are the motoneurons?

Neurons that form connections with muscles

39

What are interneurons?

Neurons that form connections with other neurons

40

What are the two types of neurons classified under axons?

1. Golgi type 1 (long axons)
2. Golgi type 2 (local axons)

41

What are examples of three neurons classified under neurotransmitters?

1. Cholinergic neurons (release acetylcholine)
2. Glutamergic neurons (glutamide)
3. Peptitergic neurons (peptides)

42

How much of the brain is composed of glia?

90%

43

What are the three classes of glia?

1. Astrocytes
2. Oligodendrocytes
3. Microglia

44

What are astrocytes and oligodendrocytes sometimes collectively known?

Macroglia

45

What is the most numerous type of glial cells?

Astrocytes

46

Name two functions of the astrocytes:

1. Repair in damaged neurons
2. Regulate flow of ions and molecules in the extracellular fluid

47

How many organelles do astrocytes contain?

Very few

48

How many organelles do oligodendrocytes contain?

Lots

49

What is the main function of oligodendrocytes?

They make myelin that forms a sheath around the axons of neurons?

50

What is myelin composed of?

Lipids

51

The myelin sheath around the axon is not continuous; what are the gaps in it called?

The nodes of ranvier

52

What do the Node of Ranvier do?

Increase the speed of electrical conduction of the axon

53

In what part of the nervous system do oligodendrocytes make myelin?

The central nervous system

54

What makes myelin in the peripheral nervous system?

Schwann Cells

55

What are microglia?

Phagocytes that remove waste

56

How many neurons in the CNS nie every day that need to be removed by microglia?

100,000