Lesson 2- The Classificiation Of Neurons

Question 1

What are the three ways of classifying or categorising neurons?

Answer 1

1. Look at the number of processes that come out of the cell body (every neuron has an axon so that’s already one process they all have) (unipolar, bipolar, multipolar)
2. Classify neuron according to how long the axon is (golgi type 1/2)
3. Classify the neuron according to the shape of the cell body (ovoid/ fusiform / triangular)

Question 2

What is a bipolar neuron?

Answer 2

A bipolar neuron has one pole being the axon, and the other pole being a dendrite. Basically a bipolar neuron only has one single dendrite coming out of the cell body. It has two processes coming out of the cell body. Form part of the retina and olfactory epithelium

Question 3

What is a multipolar neuron?

Answer 3

Most common type of neuron. Multipolar neurons have multiple dendrites coming out of the cell body.

Question 4

Golgi said you can classify neurons into two types of neurons. What are these neurons called?

Answer 4

Golgi type 1 neuron and Golgi type 2 neuron.
Golgi type 1 neuron has a long axon (PROJECTION NEURON) out of the structure to a different structure in the brain/spinal cord.
Golgi type 2 neuron has short axons (INTERNEURON) and tend to stay in the structure of which the cell body is located in.

Question 5

What is a Golgi type 2 neuron?

Answer 5

A type of neuron you can classify neurons into.
have short axons (INTERNEURON)
tend to stay in the structure of which the cell body is located in.

Question 6

What is a Golgi type 1 neuron?

Answer 6

A type of neuronal classification.
Has a long axon (PROJECTION NEURON)
out of the structure to a different structure in the brain or spinal cord.

Question 7

What are the 3 different shapes of the cell body that neurons can be classified into?

Answer 7

Fusiform, Ovoid, Triangular
FOT

Question 8

What is the ovoid shape that neuron’s cell body may take the form of?

Answer 8

Ovoid means circular or spherical

Question 9

What is the Fusiform shape that neuron’s cell body may take the form of?

Answer 9

Fusiform means fat in the middle and gradually thinnens towards the edges

Question 10

What is the triangular shape that neuron’s cell body may take the form of?

Answer 10

Triangular means triangular

Question 11

What is a pyramidal cell?

Answer 11

A pyramidal cell is found in the cerebral cortex and tends to reject inside or inner lay of cortex.
multipolar (dendrites stick out from the apex (top) and base of the cell boy) and axon sticks out of the body lots of dendrites sticking out.
Golgi type 1 neuron, projection neurons that project away from the structure

Question 12

What is the cerebral cortex?

Answer 12

The outermost layer of the brain, and is a key part of the brain for many psychological functions:
Reasoning
Emotion
Thought
Memory
Language
Consciousness
Intelligence
Personality

Question 13

What are the 6 layers of neo cortex?

Answer 13

They overly the majority of your brain and are found in every layer apart the outermost layer of the cortex.

Question 14

What is the structure of the 6 layers of neo cortex?

Answer 14

They have a triangular cell body
They are multipolar (lots of dendrites stick out of the top of the cell and the bottom, so it is referred to as an apical dendrite, and basal dendrite)
so dendrites emanate from the apex and base of the cell body.
The dendrite contains spines so they look fuzzy and a lot of receiving area to receive inputs.

Question 15

What is the pyramidal cells and its function?

Answer 15

Golgi type 1 cell (long axon/projection neuron)
produce outputs that go elsewhere in the brain.
projection neurons (all project away from the structure or the part of the cortex in which the cell body is located).
Pyramidal cells appear from the top layers, project within the cortex to other areas of the cortex, the ones in the bottom layers project out of the cortex to the other structures.

Question 16

What are spiny stellate cells in the cortex?

Answer 16

Spiny stellate cells are ovoid
multipolar
radial/horizontal
Golgi type 2 interneurons as they stay in the structure of the cortex in which the cell body is located.
Dendrites are spiny and so dark and fuzzy, very dense.
Dendritic arbour is the dark bit (the dendritic tree)
The axon breaks up into different bits, only slightly larger than the dendritic tree.

Question 17

What are Dopaminergic neurons?

Answer 17

Fusiform in shape (fat inside or middle, thin as go toward edges).
Golgi type 1/ projection neurons
Multipolar (many dendrites)

Rather than coming out of the cell body like axons do, they come out of other dendrites
Degenerate in PD, so in parkinsons disease, the neurons degenerate.

Question 18

What are Purkinje cells found in the cortex of the cerebellum?

Answer 18

Ovoid body
bipolar (2 processes) as one dendrite comes out of the cell body and then branches into other dendrites
Golgi type 1 / Projection neurons out of cerebellum cortex into deep cerebellum nuclei
Dendrites are spiny, one dendrite that divides into a huge great tree.

Question 19

Losing Purkinje cells can cause the development of what?

Answer 19

A tremor, may find it difficult to walk (ataxia), fine hand movements and speech become a problem as the cerebellum is primarily a motor structure. speech articulation problems, difficult to speak.

Question 20

What is the dendritic arbour?

Answer 20

Increases the area of dendrites allowing for more processes

Question 21

What is a unipolar neuron?

Answer 21

Found only in invertebrates
Have one process
No dendrites
Exclusive to sensory neurons in humans (pseudo-unipolar neurons)
In pseudo unipolar neurons, process leaves the cell and splits into two atonal branches