Lecture 16: Cells & Organisation of the Nervous System

Question 1

Why is integration and coordination important? Give examples

Answer 1

• They match our sensory environment with our body’s needs
• Thirsty / Drink Water
• Cold / Get Warmer
• Hear loud or scary noise / fight or flight
• See food / Am I hungry? / Order some!

Question 2

The central nervous system is composed of the:

Answer 2

• Brain / nervous + glia (non-neurons)

- Spinal Cord / neurons + glia (non-neurons)

Question 3

The peripheral nervous system is composed of:

Answer 3

• Peripheral Nerves / neurons + glia

Question 4

What are 3 general features of Glia Cells?

Answer 4

1. Support for neurons
2. Five basic types - 4 in CNS, 1 in PNS
3. Each type has a specific function

Question 5

What are 3 general features of Neurons?

Answer 5

1. Cells are specialised for transmission

2.

Question 6

The 4 cells of the Central Nervous System are:

Answer 6

1. Astrocytes
2. Microglia
3. Ependymal
4. Oligodendrocytes

Question 7

What are 3 features of Astrocytes?

Answer 7

• Supply nutrients to neurons
• Ensheath blood capillaries
• Transmit information

Question 8

What are 2 features of Microglia?

Answer 8

• Immune cells of the CNS

Question 9

What are 2 features of the Ependymal Cells?

Answer 9

• Line fluid-filled spaces of brain + spinal cord
• Circulate cerebrospinal fluid
• Have cilia

Question 10

What are 2 features of Oligodendrocytes?

Answer 10

• Support nerve fibres

- Ensheath them with myelin

Question 11

What cell is only found in the PNS?

Answer 11

• Schwann Cell

Question 12

What are some features of the Schwann Cell?

Answer 12

• They support peripheral nerve fibres

- Wrap their membrane around the axon

Question 13

What is the myelin sheath?

Answer 13

• Lipid wrapped around axon

Question 14

Where does myelin come from in the CNS vs PNS?

Answer 14

• CNS : Oligodendrocytes

- PNS : Schwann Cell

Question 15

What does the myelin sheath do?

Answer 15

• Increases conduction ( ___ n ____ n ____ n )

Question 16

What is the structure of the Neuron?

Answer 16

• Dendrites
• Cell Body
• Axon
• Axon Terminal

Question 17

What are the nodes of ranvier?

Answer 17

• The gaps between the myelin sheath

Question 18

What happens when axons become demyelinated?

Answer 18

• Impaired nerve conduction (weakness, uncoordination, visual, speech impairment)
• Multiple Sclerosis

Question 19

Describe what happens in the input zone of an axon

Answer 19

• Information is received via chemical signals by dendrites

Question 20

Describe what happens in the summation zone of an axon

Answer 20

• The axon hillock decides whether to transmit signal further
• Receiving a text, send it on or no?

Question 21

Describe what happens in the conduction zone of an axon

Answer 21

• Electrical signals between brain + spine

Question 22

Describe what happens in the output zone of an axon

Answer 22

• Chemical signals are sent to the next axon

Question 23

What are the three basic types of the nervous system?

Answer 23

• Multipolar ( ——-OE_---_-) V
• Bipolar ( ——O——- ) I
• Unipolar (one process to the side) ( ————- )

Question 24

Where does communication happen between neurons?

Answer 24

• In the synapse / synaptic cleft via neurotransmitters

Question 25

What are the 3 synapse types?

Answer 25

• Axodendritic
• Axosomatic (synapse connects to soma)
• Axoaxonic (synapse connects to axon)

Question 26

Information that goes into the brain is:

Answer 26

• Afferent (Ascending)

Question 27

Information that goes out of the brain is:

Answer 27

• Efferent (dEscending)