The Central Nervous System

Question 1

what are glial cells

Answer 1

Glial cells support the neurons in many ways, yet we rarely learn about them:
90% of human brain cells!
No action potentials or synapses with neurons

What do they do?
They surround neurons and hold them in place
They supply nutrients and oxygen to neurons
They insulate neurons from each other
They destroy pathogens and remove dead neurons

Question 2

what are the type of glial cells?

Answer 2

There are five main types of glial cell (that we have found):

• Schwann cells, which form myelin on neurons in the peripheral nervous system
• Oligodendrocytes, which have a similar role to Schwann cells, but in the central nervous system
• Astrocytes, which transport nutrients
• Microglia, which remove debris and dead cells
• Ependymal cells, which line fluid-filled cavities of the central nervous system.

Question 3

what are the 4 sections of the cns

Answer 3

• cerebral cortex
• cerebellum
• hypothalamus and pituitary gland
• medulla

Question 4

what is the cerebral cortex

Answer 4

We divide the brain up into four lobes (remember that there are also two hemispheres):

Frontal
Parietal
Temporal
Occipital

Question 5

what is the frontal lobe

Answer 5

Let’s start by looking at the frontal lobe:

Frontal lobe involved in higher mental functions.
Planning, such as recognising future consequences from current actions
Suppresses unacceptable social responses
Determine similarities between things or events in memory

Question 6

what is the parietal lobe

Answer 6

Associated with ability to interpret sensations

Damage or developmental issues in these regions can lead to
Visual agnosia
Auditory agnosia
Tactile agnosia

Specific senses not defective, nor memory, but can be a disconnect between visual, auditory and somatosensory input and higher level processing.

Agnosia is the inability to process sensory information.

The parietal lobe includes the postcentral gyrus (sensory cortex).

Question 7

what is the occipital lobe?

Answer 7

This is where the sensations from your optic nerves go.

Information from the sensory areas (the occipital lobe in this case) still has to be processed in conjunction with other areas.

Question 8

what is the temporal lobe?

Answer 8

Smell
Sound
Processing complex stimuli

Associated with memory.  
Visual memories
Processing sensory input
Spatial memory
Language
New memories

Question 9

how do the left and right hemispheres communicate?

Answer 9

• communicate through the corpus callosum
• an example: There are areas on the periphery (the outer edges) of your visual field that are only seen by one eye. This information goes to one side of the brian directly but must be shared with the other side via the corpus callosum.

Question 10

how can we get a brain image?

Answer 10

Electroencephalography (EEG)

If you place electrodes near to a person’s brain, you can record induced currents that occur due to electrical activity.

Question 11

what can we do with this info

Answer 11

This information is useful for several reasons:

Basic understanding of our brains
Clinical diagnosis
Technical aid in recovery of function