Functional Neuro Anatomy (CNS)

Question 1

What is the difference between the Central Nervous System (CNS) and the Peripheral Nervous System (PNS)?

Answer 1

The CNS is concerned with the brain and spinal cord whereas the PNS is all other aspects outside of these regions.

Question 2

What is the longitudinal fissure? and what does it separate?

Answer 2

It is the clear large groove that separates the two cerebral hemispheres of brain.

Question 3

What is the corpus callosum? and how can it help us when viewing dorsal images of the brain?

Answer 3

The corpus callosum is a dense hard structure in the brain where a large amount of neurons are gathered. It’s also known as the hard body, because relative to other cortical tissue in the brain it is more dense.

It can help us orientate ourselves when looking at sliced images of the brain.

Question 4

What are axons?

Answer 4

Axons are the transmission line of the nervous system and as bundles they help make up nerves.

Question 5

What are tracts and nerves? how are they different, how are they the same?

Answer 5

Tracts are bundles of axons travelling in the CNS (white matter)

Nerves are bundles of axons travelling in the PNS.

They are both the same however due to neuroanatomical conventions and language they are called different things.

Question 6

What are nuclei and ganglia? how are they different, how are they the same?

Answer 6

Nuclei are groups of neuron cell bodies in the CNS

Ganglia are groups of neuron cell bodies in the PNS

They adhere to the neuroanatomical language convention where they are called different things depending on where they are located.

Question 7

What are three different planes of view that are used to look at the body and the brain? how are they used?

Answer 7

1. The Horizontal plane
   This is where the brain and body are split on the horizontal plane. This can be moved up as well as down to slice at different levels.
2. The Sagittal plane
   This is where the body and brain is split from back to front.
3. The Coronal plane
   This is where the body and brain are split from left to right.

None of these planes are on a fixed position and can be moved in order to scan particular parts of the body and brain.

Question 8

What is the mid-sagittal view?

Answer 8

This is a view of the brain that is sliced directly down the longitudinal fissure. Essentially, a line that is directly down the middle of the brain.

Question 9

What is a cross section?

Answer 9

Typically in a cross section we are looking at the spinal cord, or the region where the spinal cord transitions to the brain, also known as the brain stem.

If we cut across this part of the spinal cord and the brain then this is called a cross section.

Question 10

What is a neuraxis? what do we need to be mindful of when relation to humans?

Answer 10

It is an imaginary line that is “drawn” from the tip of the spinal cord to the very front of the brain.

Note: Orientation relative to humans means that our neuraxis has a 90 degree curve in it, which then shifts neuroanatomical orientation.

Question 11

In the spinal cord, what are the anatomical orientations and where are they located?

Answer 11

1. Dorsal (to the back)
2. Posterior (to the bottom)
3. Ventral (to the belly)
4. Anterior (towards the top)

Question 12

In the brain, what are the anatomical orientations and where are they located?

Answer 12

1. Dorsal (to the top)
2. Posterior (to the back)
3. Ventral (to the bottom)
4. Anterior (to the front)

Question 13

What are some terms that are used instead of anterior?

Answer 13

Inferior and rostral

note: these all mean the same thing but they are used when looking at different parts of the brain.

Question 14

What are some terms that are used instead of posterior?

Answer 14

Susperia and cordal

note: these all mean the same thing but they are used when looking at different parts of the brain.

Question 15

When thinking about CT scans and MRI what is the horizontal plane of orientation referred to?

Answer 15

The Axial

Note: This is the same as the horizontal view it is named the axial due to the scans.

Question 16

What are the three primary divisions of the brain?

Answer 16

1. The forebrain
2. The midbrain
3. The hindbrain

Question 17

What are the two divisions of the forebrain and what do they both contain?

Answer 17

1. The Telencephalon
   Which holds the cerebral cortex, the limbic system and the basal ganglia.
2. Diencephalon
   Which holds the thalamus and the hypothalamus

Question 18

What is the midbrain and what is contained there?

Answer 18

This is the location of two pairs of colliculi - the superior colliculi and the inferior colliculi.

Question 19

What is the hindbrain and what structures are located there?

Answer 19

The hindbrain is located at the base of the brain and contains structures such as the medulla, pons, cerebellum and reticular formation.

Question 20

What is the medulla?

Answer 20

It is a system in the hindbrain that contains circuits of neurons that control functions vital for survival such as heart rate, blood pressure and respiration.

Question 21

What is the pons?

Answer 21

It literally means bridge.
The pons provides a bridge between the brain stem structures and the cerebellum. The pons also contains several clusters of nuclei. One of these clusters that runs through the pons is the reticular formation which has an influence on our level of consciousness and arousal (alertness).

Question 22

How is the CNS and PNS formed in the womb and what is its process? name the specific structures as well as the time it takes for these structures to develop.

Answer 22

18 days from conception the neural plate (which is the beginning of the brain) is formed.

Then, up to 20 days we see the formation of the neural groove.

Then, the neural groove forms the neural tube at 24 days. At the same point in time the neural crests are formed and sit above the neural tube.

The neural tube will go on to be the foundation of the CNS

and the neural crests will be the foundation of the PNS.

Question 23

How does the neural tube form the different divisions of the brain?

Answer 23

Over time the neural tube begins to form discrete enlargements or vesicles. These embryonic vesicles then develop into the major parts of the brain:

The forebrain
The midbrain
The hindbrain

Question 24

What is the cerebellum?

Answer 24

It translates from the Latin to “little brain”. The cerebellum is a relatively large structure located behind the brain stem. it is critical to the co-ordination of movement and to balance.