Brain Cells

Question 1

Account for about 90% of our brain cells

Answer 1

Glial cells

Question 2

What forms myelin

Answer 2

Oligodendrocytes

Question 3

Main types of glial cells in the CNS

Answer 3

Astrocytes, oligodendrocytes, microglia

Question 4

Form the blood-brain barrier (barrier between neuronal tissue and blood)

Answer 4

Astrocytes

Question 5

Devour and remove debris left by dead or degenerating brain cells

Answer 5

Microglia

Question 6

What is the membrane potential of a neuron?

Answer 6

-70 mV inside compared to outside

Question 7

What are the 3 phases of an action potential?

Answer 7

1. Rising phase: both Na+ and K+ channels open (membrane potential increases)
2. Repolarization: Na+ channels close (membrane potential decreases)
3. Hyperpolarization: K+ channels close (membrane potential decreases)

Question 8

What are the Nodes of Ranvier and what happens at them?

Answer 8

They are the spaces between bits of myelin where action potentials happen