T1 L5: Neural tissues

Question 1

Which embryological layer is the nervous system derived from?

Answer 1

The ectoderm

Question 2

What are afferent neurones?

Answer 2

Transmit information to the CNS

Question 3

What are efferent neurones?

Answer 3

They’re motor neurones transmitting information from the CNS to the effector organs

Question 4

Where is the nucleus of a parasympathetic ganglion?

Answer 4

In the periphery. They’re also small

Question 5

Where is the nucleus of a sensory ganglion?

Answer 5

In the centre. They’re large

Question 6

What are Brodmann’s areas?

Answer 6

Numeric descriptions of areas of the brain

Question 7

What is found in Broadmann’s area 4?

Answer 7

The primary motor cortex

Question 8

What is found in Brodmann’s area 17?

Answer 8

The primary visual cortex

Question 9

What is the difference between the different Brodmann’s areas?

Answer 9

They each have a different input and output as well as function

Question 10

Where are pyramidal neurones found?

Answer 10

In the cerebral cortex

Question 11

Where are Purkinji neurones found?

Answer 11

In the cerebellar cortex

Question 12

Where are pseudounipolar neurones found?

Answer 12

In the dorsal root ganglia. They are sensory neurones

Question 13

What are the characteristics of a bipolar neurone?

Answer 13

1 dendrite and 1 axon

Question 14

What are the characteristics of a pseudounipolar neurone?

Answer 14

1 axon and 1 dendrite but the axon is sticking out on the side of the neurone

Question 15

How big is the synaptic gap between chemical synapses?

Answer 15

~ 30nm

Question 16

What is a divergent neurone?

Answer 16

A single neurone that sends output signals to many neurones

Question 17

What is a convergent neurone?

Answer 17

Multiple inputs influence a single neurone

Question 18

Where do interneurons occur?

Answer 18

Only in the CNS

Question 19

What structures are the most common causes of tumours in the NS?

Answer 19

Glia

Question 20

What is Glia

Answer 20

Cells that support neurones

Question 21

What are some characteristics of Glia?

Answer 21

They have no action potentials
Don’t form synapse
Are able to divide
They form the myelin sheath

Question 22

What is the function of Oligodendorcytes?

Answer 22

They produce and maintain the myelin sheath in the CNS. One Oligodendrocyte can myelinate multiple axons on different neurones

Question 23

What is the function of Astrocytes?

Answer 23

They are star-shaped cells that assist neuronal growth/development (are neurotrophic).
They protect neurones from harmful substances
They also influence the blood-brain barrier and blood flow

Question 24

What is the function of microglia?

Answer 24

They are immune cells that protect cells from disease, migrate to sites of injury, engulf microbes and debris.

Question 25

What embryological layer do microglia originate from?

Answer 25

From the mesoderm like other immune cells. They are also able to develop from monocytes

Question 26

What is the function of ependymal cells?

Answer 26

They line the brain’s ventricles and the central canal of the spinal cord

Question 27

What cells of the CNS work with cilia and microvilli?

Answer 27

Ependymal cells. They basically create a sort of epithelium

Question 28

What is the function of Schwann cells?

Answer 28

They are only found in the PNS. They produce and maintain the myelin sheath.
A single Schwann cell can only associate with a single axon

Question 29

What is the function of satellite cells?

Answer 29

They are only found in the PNS (muscles).

They regulate exchange of materials between neurones and interstitial fluid

Question 30

What is a glioma?

Answer 30

A type of tumour that originates from glial cells. They are usually highly malignant and grow rapidly. Very difficult to remove completely with surgery. Usually form within the cranium

Question 31

What is a neuroblastoma?

Answer 31

A cancerous tumour most common in children and infants (during development when the levels of Catecholamine are increased). Occurs outside the cranium.
Survivors often develop neurological problems ~ 30 years later.
Treatment and prognosis depends of the type.