Neural Tissue

Question 1

In the body superior means up and inferior means down, but in the brain what terms refer to up and down?

Answer 1

• dorsal = up or top like a dolphins fin on the top
• ventral = down

Question 2

In the body ventral means up and dorsal means back, but in the brain what terms refer to front and back?

Answer 2

• front = rostral
• back = caudal

Question 3

On the brain are areas that sink in, similar to the crypts in the GI and then there are area that move out, as per the image below. What are the 2 terms used to describe these anatomical landmarks?

Answer 3

• gyrus = look like bumps
• sulcus = brain Sinks in resembling the crypts

Question 4

What is the neuronal doctrine theory?

Answer 4

• nervous system is made up of discrete individual cell
• all cells are individual BUT mutually rely on one and another

Question 5

What is the cerebral cortex?

1 - outermost region of the cerebrum

2 - inner most layer of the cerebrum

3 - attached to the top of the brain stem

4 - located at the back of the brain, referred to as the mini brain

Answer 5

1 - outermost region of the cerebrum

• made up of neuronal cell bodies, so appears grey

Question 6

What is a Brodmann area?

Answer 6

• boundaries of the brain
• determined by histological architecture and function, essentially the tissue and cell type

Question 7

How many Brodmann areas are there in the brain?

Answer 7

• 52

Question 8

Why are Brodmann areas of the brain important?

Answer 8

• they generally posses specific functions

Question 9

Brodmann area 17 is located on either side of the calcarine sulcus, on the medial surface of the occipital lobe. What is this area also commonly referred to as and what is its function?

1. primary somatosensory cortex
2. primary visual cortex
3. primary motor cortex
   
   1. primary auditory cortex

Answer 9

2. primary visual cortex

Question 10

Brodman area 4 is located in the posterior portion of the frontal lobe. What is it more commonly known as and what is its function?

1. primary somatosensory cortex
2. primary visual cortex
3. primary motor cortex
4. primary auditory cortex

Answer 10

3. primary motor cortex
   - heavily involved in motor function

Question 11

The head of a neuron is called the cell body. It has appendages that are designed to receive communications from other cells, what are these called?

1. dendrites
2. axon hillock
3. axon terminal
4. oligodendrocyte

Answer 11

1. dendrites

Question 12

The head of a neuron is called the cell body. What is the name where the cell body attaches to the axon and what is its role?

1. dendrites
2. axon hillock
3. axon terminal
4. oligodendrocyte

Answer 12

2. axon hillock
   - initiates an action potential

Question 13

What is the end of the axon furthest away from the cell body called?

1. dendrites
2. axon hillock
3. axon terminal
4. oligodendrocyte

Answer 13

3. axon terminals
   - synapses with other neurons or tissues

Question 14

Axon collaterals can be found along the axon, between the cell body and the axon terminals. What is the function of these?

1. provide modulation of the cell firing
2. wrap around the axon body ensuring good conduction
3. connect the axon hillock the the axon

Answer 14

1. provide modulation of the cell firing

Question 15

How do we know if a neuronal cell is a white matter neuron?

Answer 15

• if it is encapsulated in myelin sheath
• myelin is a white protein

Question 16

In the CNS which cell is responsible for myelinating neurons?

1. microglia
2. schwann cell
3. oligodendrocytes
4. astrocytes

Answer 16

3. oligodendrocytes
   - able to do this for multiple neurons

Question 17

In the PNS which cell is responsible for myelinating neurons?

1. microglia
2. schwann cell
3. oligodendrocytes
4. astrocytes

Answer 17

2. Schwann cells
   - one neuronal cell per schwann cell

Question 18

Each neuron is a separate entity with a limiting cell membrane, like all other cells in the body. Why is this important?

Answer 18

• confirms neuronal doctrine
• all cells are individual but dependent on one another

Question 19

Morphology refers to the size and shape of neurons. How many different types of neuronal cells are there?

1. 1
2. 2
3. 3
4. 4

Answer 19

4. 4

Question 20

Morphology refers to the size and shape of neurons. There are 4 different types of neuronal cells. What are they?

1. unipolar, bipolar, pseudo-unipolar, facet-polar
2. membrane polar, bipolar, pseudo-unipolar, multipolar
3. synaptic polar, bipolar, pseudo-unipolar, multipolar
4. unipolar, bipolar, pseudo-unipolar, multipolar

Answer 20

4. unipolar, bipolar, pseudo-unipolar, multipolar

Question 21

What are dendrites in neuronal cells?

1. part of neuron responsible for immunity
2. part of neuron that facilitates conduction
3. protoplasmic appendages of cell membrane
4. part of nucleus of neuronal cells

Answer 21

3. protoplasmic appendages of cell membrane
   - designed to facilitate communication between cells

Question 22

In some cells, what proportion of the neurones can consist of dendrites?

1. 10%
2. 30%
3. 60%
4. 95%

Answer 22

4. up to 95%

Question 23

In a neuronal cell, what is the soma?

1. neuronal cell body containing nucleus
2. appendages of neuronal cell
3. connection between neuronal cell and axon
4. connection between post synapse and pre synapse

Answer 23

1. neuronal cell body containing nucleus
   - metabolic activity and protein synthesis occur here

Question 24

Neuronal transmitters are produced where in the neuronal cell, before being stored in the synaptic vesicles?

1. soma (cell body)
2. nucleus
3. axon hillock
4. axon terminal (pre synapse)

Answer 24

1. soma

Question 25

Which part of the neuronal cell is responsible for generating an action potential due to the high density of the voltage gated Na+ channels, allowing the threshold to be reached, which then triggers the action potential? 1. dendrites 2. axon hillock 3. axon terminal 4. oligodendrocyte

Answer 25

2. axon hillock

Question 26

What is saltatory conduction? 1. propagation of action potential along myelinated axons 2. propagation within the pre synapse 3. continues propagation along non-myelinated axons 4. propagation along the axon hillock

Answer 26

1. propagation of action potential along myelinated axons - saltatory comes from the greek to 'leap' - allows very fast action potentials to travel from node to node in neurons - 120m/s

Question 27

What is the difference between an afferent and efferent neuron?

Answer 27

- afferent = away from the body to CNS (sensory) - efferent = effector neurons from CNS to PNS (muscles, glands etc)

Question 28

What are interneurons?

Answer 28

- carry messages between neurons (can be inhibitory or excitatory) - facilitate communication

Question 29

Oligodendrocytes are a form of glia cells. What is the function of these cells? 1. myelinate neurons in the CNS 2. blood brain barrier, energy metabolism, reaction to injury 3. immune function 4. synthesise neurotransmitters

Answer 29

1. myelinate neurons in the CNS

Question 30

Astrocytes are a form of glia cells. What is the function of these cells? 1. myelinate neurons in the CNS 2. blood brain barrier, energy metabolism, reaction to injury 3. immune function 4. synthesise neurotransmitters

Answer 30

2. blood brain barrier, energy metabolism, reaction to injury

Question 31

Microglia are a form of glia cells that can be activate or dormant. What is the function of these cells? 1. myelinate neurons in the CNS 2. blood brain barrier, energy metabolism, reaction to injury 3. immune function 4. synthesise neurotransmitters

Answer 31

3. immune function - think M like macrophage

Question 32

What is the main composition of oligodendrocytes? 1. peptides 2. proteolipid proteins (80%) 3. proteins 4. glycosaminoglycans

Answer 32

2. proteolipid proteins (80%) - myelin basic proteins

Question 33

In addition to myelin basic protein and proteolipid protein that make up oligodendrocytes, myelin associated glycoprotein is also an important protein, what is its main function?

Answer 33

- facilitates interactions between the axon and myelin

Question 34

Myelinated neurons are larger than non-myelinated neurons, \>1.5um and \<1.5 um in diameter, respectively. Myelination allows nerve conduction velocity, allowing for a decrease in the nerve size. Without myelinated nerves, what would this mean for the nerve diameter? 1. would make no difference 2. we would need huge nerve diameters 3. we would need smaller nerve diameters 4. we would need to slow nerve conduction

Answer 34

2. we would require huge nerve diameters to transmit information

Question 35

If a myelinated neurons loses its myelin sheath, what can this cause? 1. nothing it would grow back 2. nerve would become non-myelinated, but function normally 3. can cause axon degeneration and function, but can repair to some degree

Answer 35

3. can cause axon degeneration and function, but can repair to some degree - linked with diseases such as multiple sclerosis

Question 36

What is the difference between demylination and unmyelinated?

Answer 36

- demylination = was myelinated but lost due to disease/disorder - unmyelinated = was never myelineated

Question 37

Microglia cells are the immune cells of the nervous system, with lineage to macrophages. Are they able to phagocytose pathogens?

Answer 37

- yes - also clear cellular debris

Question 38

Microglia mature at birth and are at the greatest number just prior to birth. Why do the microglia down regulate and become ramified (resting)? 1. needed to protect the brain, but then blood brain barrier forms and does this job 2. not as likely to get an infection as we get older 3. blood pressure increases around the brain and kills of microglia 4. microglia are unable to cross the blood brain barrier

Answer 38

1. needed to protect the brain, but then blood brain barrier forms and does this job

Question 39

Astrocytes are an important glia cell type of the nervous system, what are the main functions?

Answer 39

- provide structural - glucose supply - maintain ionic enviroment - neurotransmitter uptake - repair - form blood brain barrier

Question 40

What does synaptogenesis refer to?

Answer 40

- formation of new synapses between neurons - regulated by astrocytes

Question 41

The blood brain barrier controls what does or does not enter the nervous system. It is composed of 3 key things, what are they? 1. vascular endothelial cells, astrocytes, microglia 2. vascular endothelial cells, microglia, pericytes 3. vascular endothelial cells, astrocytes, oligodendrocytes 4. vascular endothelial cells, astrocytes, pericytes

Answer 41

4. vascular endothelial cells, astrocytes, pericytes

Question 42

There is evidence to suggest that an important part of the nervous system becomes more permeable as we age, and has been linked with confused states and disorders. What is it that supposably becomes more permeable in the brain?

Answer 42

- blood brain barrier

Question 43

Astrocytes are stellate cells (star like pattern) found throughout the CNS. There are 2 broad classifications, depending on if they are located in white or grey matter, what are they?

Answer 43

- white matter = fibrous astrocytes - grey matter = protoplasmic astrocytes

Question 44

What is glutamate? 1. neurotransmitter 2. hormone 3. steroid 4. medicaiton

Answer 44

1. neurotransmitter - amino acid neurotransmitter functions as a an excitatory neurotransmitter (AMPA and NMDA)

Question 45

What is the glutamate-glutamine shuttle? 1. how glutamate is moved around the neuronal cell 2. how glutamate is synthesised in the soma of the neuron 3. how glutamate is recycled from synaptic cleft by astrocytes 4. how glutamate is released by vesicles into the synaptic cleft

Answer 45

4. how glutamate is recycled from synaptic cleft by astrocytes - recycling of glutamate - glutamate is released into synaptic space - glutamate binds receptors on the post synapse - recycled by pre-synapse or astrocytes - ultimately ends up back in pre synapse

Question 46

The glutamate-glutamine shuttle describes how glutamate, a neurotransmitter is released into synapse following an action potential. It can bind with receptors on the post synapse, be recycled by pre-synapse or be absorbed by receptors on astrocytes. Once glutamate has been re-taken up by astrocytes, what happens to it? 1. converted into glutamine in astrocyte, then back into glutamate in pre-synapse 2. converted into dopamine in astrocyte, then back into glutamate in pre-synapse 3. converted into serotonin in astrocyte, then back into glutamate in pre-synapse 4. converted into glutamine in astrocyte, then back into glutamate in synaptic cleft

Answer 46

1. converted into glutamine in astrocyte, then back into glutamate in pre-synapse - absorbed by glutamine transports (Na+ dependent) - glutamine synthetase acts on it leaving glutamine - glutamine released back into pre-synaptic neuron - re-converted back into glutamate in pre synapse

Question 47

In the CNS there is an additional type of glia cell called the ependymal cells, which are ciliated epithelial glial cells. These cells line the inside of the ventricles and the spinal spinal cords. What is the main function of the ependymal calls?

Answer 47

- maintain fluid homeostasis - direct contact with cerebral spinal fluid (CSF) and brain parenchyma (brain tissue) - facilitate transport of electrolytes and solutes into brain and CSF

Question 48

Schwann cells myelinate axons in the PNS. How many axons can one schwann cell myelinate?

Answer 48

- one axon only - also important for providing substrate for axons to grow long

Question 49

Satellite glia cells are located in the PNS, exclusively in the peripheral ganglia, sensory parasympathetic and sympathetic ganglia. How do they support the neurons?

Answer 49

- wrap around the neuronal cell bodies - function similiar to astrocytes, but unknown

Question 50

Do neurons and glia cells have action potentials?

Answer 50

- no, only neurons

Question 51

Do neurons and glia cells both divide in mitosis?

Answer 51

- no, only glia cells

Question 52

What is a glioma? 1. a group of glial cells 2. a glial cell found in a lymph node 3. tumour cells derived from glial cells 4. glial cell that has undergone apoptosis

Answer 52

3. tumour cells derived from glial cells

Question 53

Are gliomas dangerous?

Answer 53

- yes, highly malignant - glial cells can proliferate and therefore increase in size

Question 54

What is the most common treatment for gliomas?

Answer 54

- radiotherapy due to accessibility

Question 55

What does intra-axial refer to?

Answer 55

- within the brain parenchyma

Question 56

What is neuroblastoma mean? - neuro = nerve cells - blastoma = immature cells

Answer 56

- cancer that develops from immature nerve cells - occur outside of the cranium - common in adrenal glands, kidneys, neck, spine

Question 57

In a patient with neuroblastoma, what are the outcomes? - neuro = nerve cells - blastoma = immature cells

Answer 57

- outcomes are generally good - patients tend to develop neurological issues in later life