cells of the nervous system

Question 1

what are the two major cells in the nervous system?

Answer 1

1. neurons
2. glial cells

Question 2

what are neurons ?

Answer 2

nerve cells that are electrically excitable cells and communicate with other cells via specialised connections called synapses. They make up the majority of nervous tissue

Question 3

what are glial cells ?

Answer 3

non-neuronal cells in the nervous system that maintain homeostasis, form myelin, and provide support and protection for neurons

Question 4

what are the 3 main stages of Information passing within neurons is electrically?

Answer 4

1. Signals arrive at the dendrites - these signals change the electrical charge of the cell (up and down)
   2.If the charge reaches a set point - threshold - an action potential occurs and travels down the axon
2. This is a single punctate event, so information is coded by the rate of firing of action potential

Question 5

what are the 5 types of glial cells?

Answer 5

1. Schwann cells
2. Oligodendrocytes
3. Astrocytes
4. Ependymal cells
5. Microglial cells

Question 6

what are Schwann cells?

Answer 6

• they are the cells that form myelin in the peripheral nervous system
• assists in the regeneration and regrowth of axons

Question 7

what is the difference between myelinated and unmyelinated speeds

Answer 7

myelinated - 150m/s
unmyelinated - 0.5 - 10m/s

Question 8

what are oligodendrocytes?

Answer 8

• they form the myeline sheath in axons in the central nervous system
• they can myelinate 50 axons

Question 9

what do astrocytes do?

Answer 9

they control the brain environment

Question 10

what are the 4 main ways astrocytes control the environment of the brain?

Answer 10

1. regulates chemicals around neurons
2. regulates blood flow around the brain
3. nervous system repair
4. maintenance of the blood brain barrier