Neurons

Question 1

What do neurons do?

Answer 1

They conduct electrical impulses.

Question 2

What word can be used to describe the reproducibility of neurons? What does this mean for damaged neurons?

Answer 2

They are amitotic. They can be repaired, but if they die will not grow back.

Question 3

What can be said about the resource consumption of neurons?

Answer 3

Neurons have a high demand for glucose and O2.

Question 4

What are the three functional regions of a neuron?

Answer 4

The receptive region, the conducting region, and the secretory region.

Question 5

What two pieces make up the cell body of a neuron? What are they called together?

Answer 5

The nucleus and the granular cytoplasm. They are also called the biosynthetic centre.

Question 6

What is another name for the ribosome clusters of neurons?

Answer 6

Nissl bodies

Question 7

What are there a lot of in neurons? (3)

Answer 7

Mitochondria, rough ER, and golgi apparatus

Question 8

What is a nuclei?

Answer 8

A cluster of cell bodies in the CNS.

Question 9

What is a ganglion?

Answer 9

A cluster of ell bodies in the PNS.

Question 10

What is a tract?

Answer 10

A cluster of axons in the CNS.

Question 11

What is a bundle of axons in the PNS called?

Answer 11

A nerve.

Question 12

What kind of electrical signals do dendrites use?

Answer 12

Graded potentials.

Question 13

What is the beginning of the axon called?

Answer 13

The axon hillock.

Question 14

What increases the rate of conduction of an axon?

Answer 14

The diameter of the axon.

Question 15

How many terminal branches (axonal terminals) are there per axon?

Answer 15

roughly ten thousand

Question 16

What is the missing organelle from the axon that is in the cell body?

Answer 16

The Nissl body.

Question 17

What do we call a movement of something from the cell body to the axon?

Answer 17

An anterograde movement.

Question 18

What do we call a movement of something from the axon terminal to the cell body?

Answer 18

A retrograde movement.

Question 19

What are the 4 types of supporting CNS cells? Lightly describe them.

Answer 19

1. Astrocytes are start shaped and attach neurons to capillaries. They guide growing neurons and facilitate nutrient exchange and clean the environment.
2. Microglia are protective cells and touch neurons to monitor well being. They can turn into macrophages.
3. Ependymal cells line cavities in the brain and spinal cord. They have cilia.
4. Oligodendrocytes provide myelin sheaths to the CNS.

Question 20

What are the 2 types of supporting PNS cells? Lightly describe them.

Answer 20

Satellite cells surround cell bodies in a ganglia. They are the astrocytes of the PNS.
Schwann’s cells form myelin sheathes. Each sheathe is a wrapped up Schwann’s Cell.

Question 21

What are the three structural classifications of neurons?

Answer 21

Unipolar, bipolar, and multipolar.

Question 22

What structural classification of neurons is most common?

Answer 22

Multipolar.

Question 23

Where are bipolar neurons found?

Answer 23

In some sensory organs.

Question 24

Where are unipolar neurons found?

Answer 24

Transmitting sensory info towards the CNS.

Question 25

What are the three functional classes of neurons?

Answer 25

Sensory, Motor, and Association neurons

Question 26

Which way do sensory neurons fire?

Answer 26

Towards the CNS

Question 27

Where are motor neurons found?

Answer 27

Muscles and glands

Question 28

Which nervous system are the cell bodies of motor neurons found?

Answer 28

In the CNS

Question 29

Where are association neurons found? How abundant are they?

Answer 29

They are between sensory and motor neurons, they are almost entirely in the CNS and make up 99% of neurons.