Neurons

Question 1

What is a neuron

Answer 1

A neuron is a cell which is specialised for electrical cell signalling

Question 2

How does an impulse get passed between each neuron

Answer 2

By the connections made between t adjacent dendrites

Question 3

Where do the axon potentials travel along

Answer 3

They travel alone the axon from the axon hillock

Question 4

What are the 2 types of neuron communication

Answer 4

Chemical and electrical

Question 5

How does chemical communication between neurons occur

Answer 5

Via neurotransmitters

Question 6

Examples of neuro transmitters for chemical commuincation

Answer 6

Serotonin
Glutamate

Question 7

How does electrical communication occur between neurons

Answer 7

Via direct flow of ions

Question 8

Explain chemical synaptic transmission

Answer 8

The axon potential arrives to the axon terminal on the pre-synaptic neuron, where it becomes depolarised in the terminal membrane. This causes the voltage gated calcium channels to open and a calcium influx. This calcium influx triggers the neurotransmitters to be released into the synaptic cleft towards the post synaptic neuron

Question 9

How do neurons differ from each other

Answer 9

Size
Morphology
Neurotransmitter content
Electrical properties

Question 10

What is neural plasticity

Answer 10

Changes in the neuronal structure and function due to neural activity built off the basis of learning and memory

Question 11

What is spine remodelling linked to

Answer 11

Neural activity

Question 12

What are oligodendrocytes

Answer 12

They are myelinated cells of the CNS
They are unique to vertebrates
Rapid nerve conduction due to the myelination of segments of axons

Question 13

What is the myelin sheath composed of

Answer 13

70% lipids
30% proteins

Question 14

How is the myelin sheath formed

Answer 14

The myelin sheath is formed by wrapping the axons by the oligodendrocye processes

Question 15

What are microglia

Answer 15

Resident immune cells of the CNS

Question 16

Where do microglia originate

Answer 16

They originate in the yolk sac progenitors that migrate into the CNS

Question 17

How do microglia work

Answer 17

In a resting state the microglia are highly ramified motile processes but upon activation they retract and become ameboid and motile

Question 18

What is the role of microglia

Answer 18

They proliferate at the sites of injury
Phagocytosis
Immune surveillance
Synaptic plasticity

Question 19

What are astrocytes

Answer 19

They are start like cells which are the most numerous glial cell in the CNS, they are highly heterogenous

Question 20

What do astrocytes contribute to

Answer 20

The blood brain barrier

Question 21

Where are oliodendrocytes most numerous

Answer 21

In white matter

Question 22

What is the structural function of astrocytes

Answer 22

They define brain micro-architecture

Question 23

What other functions do astrocytes have

Answer 23

They envelop synapses
Metabolic support
Neurovascular coupling
Proliferate diseases

Question 24

What are the 3 types of specialised astrocytes

Answer 24

Radial glia
Bergmann Glia
Muller cells

Question 25

What are radial glia important for

Answer 25

Important for brain development

Question 26

Where are bergmann glia found

Answer 26

In the cerebellum

Question 27

Where are muller cells found

Answer 27

Retina

Question 28

What is an abundance of neuronal cell bodies called

Answer 28

Nuclei

Question 29

What do axons gather together into

Answer 29

Tracts

Question 30

Tracts that cross in the midline are called

Answer 30

Commissures

Question 31

Where are cell bodies and supporting cells located in the PNS

Answer 31

Ganglia

Question 32

In the PNS what do axons bundle into

Answer 32

Nerves

Question 33

In the PNS what are axons enveloped in

Answer 33

Schwann cells

Question 34

What is the blood brain barrier formed of

Answer 34

Endothelial cell tight junctions, basement membrane, astrocyte end feet, pericytes

Question 35

What is the blood brain barrier sensitive too and what problems does this cause

Answer 35

The blood brain barrier is sensitive to inflammation, hypertension, trauma and ischemia which can cause problems for drug delivery

Question 36

What are ependymal cells

Answer 36

These are epithelial-like cells which line the ventricles in the brain and the central canal in the spinal cord

Question 37

What are the function of the ependymal cells

Answer 37

Cerebrospinal fluid production Cerebrospinal fluid flow Cerebrospinal fluid absorption

Question 38

What facilities the flow on ependymal cells

Answer 38

They are ciliated which facilities the flow

Question 39

What do the ependymal cells allow to happen

Answer 39

Allow for solute exchange between the nervous tissue and cerebrospinal fluid

Question 40

What is the choroid plexus

Answer 40

They are frond like projections in the ventricles

Question 41

How are the choroid plexus formed

Answer 41

They are formed from modified ependymal cells which are highly vascularised with a large surface area

Question 42

What is the main function of the choroid plexus

Answer 42

Production of cerebrospinal fluid by plasma filtration driven by solute secretion