Week 12 - Biological Bases

Question 1

What are the four types of brain cells?

Answer 1

Neurons - nerve cells in the brain

Glial cells - support the neurons + astrocytes (can communicate between eachother) and oligodendrocytes (form the myelin sheaths that insulate neurons)

Ependymal cells - line the CSF-filled ventricles and are responsible for making new neurons (ie neurogenesis)

Microglia - remove dead or degenerating neurons (phagocytosis)

Question 2

What are the four main parts of a neuron?

Answer 2

Soma (cell body)
Dendrites
Axon
Presynaptic Terminals

Question 3

What are neurites?

Answer 3

Things that come off the cell body eg axons and dendrites (bring information in to the cell)

Question 4

How do we classify neurons?

Answer 4

1. The number of neurites (unipolar, bipolar, multipolar)
2. Their dendrites (how many they have and if they have spines)
3. Axon length
   - Golgi type I - long ‘internuncial’ (axon is sent from one brain region to another)
   - Golgi type II - small ‘interneurons’ (axon stays within a brain area and communicates with cells coming in and out of that brain area)
4. Neural connections - primary sensory (dorsal) or motor neurons (ventral)

Question 5

What are stellate and pyramidal neurons?

Answer 5

stellate - star-shaped
pyramidal - triangular (normal)

Question 6

Why are dendritic spines important?

Answer 6

More spinal area creates greater surface area for communication and learning and memory.

Question 7

Do dendritic trees stay constant or change?

Answer 7

They can change (ie grow or receed) depending on their level of use. This change is called neuroadaptation.

Question 8

What are afferent and efferent neurons?

Answer 8

Afferent - neuron that is going to a synapse connection (arriving)

Efferent - neuron that is going from a synapse connection (exiting)

Question 9

The _____ _____ is the difference between the electrical charge of the outside and inside of a cell membrane
- if there is a polar charge on one side of the membrane relative to the other, positive charge will flow to the other side

The _____ _____ is the difference between the number of a particular ion or particle on the outside and inside of a cell membrane
- if there is a high concentration of a particle on one side of the membrane compared to the other, the particles will flow to the other side

Answer 9

a) Electrical gradient

b) Concentration gradient