SFP: CNS neurons and neuroglia

Question 1

Describe the differences between gray matter and white matter

Answer 1

White matter is largely axons, while grey matter is mostly cells

Question 2

Describe the location of grey and white matter in the spinal cord and brain

Answer 2

In the cord, white matter is on the outside and grey matter is on the inside. In the brain, grey matter is on the outside and white Matter is on the inside

Question 3

Describe nuclei

Answer 3

clusters of neurons in the CNS

Question 4

describe ganglia

Answer 4

clusters of neurons in the PNS

Question 5

describe cortex

Answer 5

layers of cell bodies (grey matter) found on the outside of the brain

Question 6

describe nerves

Answer 6

bundle of axons in the PNS

Question 7

describe tracts

Answer 7

bundles of axons in the CNS

Question 8

describe the function of neurons

Answer 8

signal processing and communication cells in the nervous system

Question 9

what are nissl bodies?

Answer 9

ribosomes in neurons

Question 10

do neurons undergo mitosis?

Answer 10

no!

Question 11

what are the major structural components of a neuron?

Answer 11

dendrites, cell body, axon, synaptic bouton

Question 12

what is the functional role of dendrites?

Answer 12

they receive input from neighboring neurons

Question 13

describe dendtritic spines

Answer 13

small protrusions on dendrites that contain receptors for neurotransmitters and are associated with synaptic contacts.

Question 14

what is associated with more dendritic spines

Answer 14

having more dendritic spines is associated with greater synaptic capacity and efficacy

Question 15

describe the cell body

Answer 15

where metabolic support occurs; lots of mitochondria and nissl bodies

Question 16

describe axons

Answer 16

this is where action potentials take place; have microtubules to move neurotransmitters. Neurons have only one axon, but it can branch

Question 17

describe axon terminals (synaptic boutons)

Answer 17

Site of signal transfer from one neuron to the next; they have vesicles containing neurotransmitter

Question 18

describe the release of neurotransmitters from axon terminals

Answer 18

The presynaptic neuron has vesicles containing neurotransmitters. The cascade of events following an action potential causes the release of these neurotransmitters into the synaptic cleft. The neurotransmitters then bind to receptors on the postsynaptic neuron.

Question 19

describe anterograde axonal transport

Answer 19

Transport away from the cell body, which is very common for neurotransmitters. the process uses the microtubule kinesin

Question 20

describe retrograde axonal transport

Answer 20

Transport from the axon terminal toward the cell body. This is very common with growth factors so they can aid with transcription/translation in the cell body. the process uses the microtubule dynein

Question 21

Differentiate between afferent and efferent neurons

Answer 21

Afferent move stimuli towards the CNS, while efferent move stimuli away from the CNS

Question 22

Name the types of neuroglia and the basic function of neuroglia.

Answer 22

They are support cells, and heavily outweigh neurons in number. They big types are astrocytes, microglia, oligodendrocytes, and ependymal cells

Question 23

Describe the structural and functional characteristics of astrocytes

Answer 23

They maintain the environment around neurons; gather up excess glutamate, play a role in the blood-brain barrier, and are bound by tight junctions. They also take up ions from the extra cellular fluid

Question 24

describe oligodendrocytes

Answer 24

They are important for making myelin and providing support. One oligodendrocytes can myelinate many axons

Question 25

describe ependymal cells

Answer 25

They line the ventricles of the brain and regulate CSF. These are bound by tight junctions. They contain cilia to help circulate CSF and are found at the choroid plexus to form CSF

Question 26

describe microglia

Answer 26

The macrophages of the brain. They respond to trauma, infection, and other injury. They activate and become motile and recruit other cells. With neurodegeneration, we see a lot of activated microglia

Question 27

which glial cells release ROS and cytokines?

Answer 27

microglia

Question 28

what do nissl stains show? are there cell bodies visible?

Answer 28

gray matter; cell bodies present

Question 29

what do myelin stains show? are there cell bodies visible?

Answer 29

white matter; no cell bodies present

Question 30

describe convergence and divergence

Answer 30

convergence: single neuron can receive input from many sources.

divergence: one axon can branch to impact cells in different locations.

Question 31

convergence and divergence are seen in what kinds of neurons?

Answer 31

motor; sensory