Lesson 1 - Properties Of Neurons

Question 1

In the brain there are two broad classes of cells which are joined together to form normal functioning brain tissue. What are they?

Answer 1

Neurons, the nerve cells that send and receive signals.
Glia, cells that provide structure in the brain

Question 2

In every brain there are two broad classes of cells that are joined together to form the normal functioning brain tissue. They are?

Answer 2

Neurons and Glia cells

Question 3

How many neurons are there in the human brain? And how long do you carry them for?

Answer 3

Around 100 billion.
You carry the, for the rest of your life, they don’t really die off.

Question 4

Where can you find Glial cells or Neuroglia?

Answer 4

They are important and found in some areas of the brain like the thalamus, they outnumber neurons by 10:1

Question 5

What fraction of all neurons in the brain are found in the cerebellum?

Answer 5

4/5 of all neurons in the brain are found in the cerebellum

Question 6

What’s the function of the cerebellum?

Answer 6

The cerebellums function is for motor control, such as balance and movement

Question 7

What can you find in neurons that can also be found in cells in the rest of your body?

Answer 7

A plasma membrane (holds everything together), a nucleus and mitochondria, and a Golgi complex.

Question 8

What can’t you find in the rest of your cells in your body that you can find in neurons?

Answer 8

The axon, synapse, and dendrites

Question 9

What’s the function of an axon?

Answer 9

The axon connects the neurons to other parts of the nervous system

Question 10

What’s the axon hillock?

Answer 10

An area of the cell body called the Axon hillock gives rise to the axon.

Question 11

How long is the axon? And how far can it travel?

Answer 11

The axon can travel distances ranging from microns to metres and can travel 3 metres to get to the spinal cord. The axon varies in how long it is.

Question 12

What is the axonal membrane?

Answer 12

The axonal membrane is excitable, capable of carrying an action potential (an electrical wave) starting off at the cell body and goes down to the axon at the end of the synaptic terminal. The axonal membrane is specialised for the generation and proportion of action potentials

Question 13

What is the function of the synapse?

Answer 13

The synapse connects with the next cell in the chain, acting as a point of specialised contact between two neurons.
Charles Sherrington introduced this name, deriving from Greek word meaning to connect.
The first cell connects with the next cell, as it’s a specialised contact between two neurons in the brain

Question 14

What’s the function of dendrites?

Answer 14

Dendrites receive inputs from other parts of the nervous system.

Question 15

What does a dendrite look like?

Answer 15

Tends to be thicker and shorter than the axon, highly branched allowing for dense network of processes. This is supported by the dendritic I arbour which increases the area of dendrites allowing for more processes

Question 16

What does the dendritic arbour or spines help with?

Answer 16

Helps increase the area of the dendrites allowing for more processes to come into the cells, or more inputs to be received from other parts of the nervous system

Question 17

What are spines?

Answer 17

Spines are constantly moving and changing shape as it has small fibres inside (2 microns) and contain filaments made of actin and are components of muscle. As the spines are constantly changing shape this means other cells coming into the cell is constantly changing.

Question 18

What will affect the impact that spines or dendrites have on the cell that is receiving the input?

Answer 18

How big and wide the top part of the spine is

Question 19

The brain is constantly ___ as it is a very _____ system

Answer 19

Changing, dynamic

Question 20

What is a nucleus?

Answer 20

Contains DNA (cells genetic code) translating the genetic code to the stuff the cell needs. The nucleus is centrally located in the cell.
The rough endoplasmic reticulum takes the DNA and synthesise proteins from it

Question 21

What is the rough endoplasmic reticulum?

Answer 21

In the endoplasmic system, the rough endoplasmic reticulum takes the DNA and synthesises or makes proteins from nucleus, either adding to the function or adding to the structure of the cell

Question 22

What is the smooth endoplasmic reticulum?

Answer 22

In the endoplasmic system, the smooth endoplasmic reticulum synthesise or creates fats (so the cell membrane itself is made out of fat) which neurons need (the fat)

Question 23

So to summarise, what does the rough endoplasmic reticulum do? And what does the smooth endoplasmic reticulum do?

Answer 23

Rough endoplasmic reticulum synthesises (creating) proteins the cell needs, taken from DNA, either adding to the structure or function of the neuron.

Smooth endoplasmic reticulum creates fats that the neurons will need. The cell membrane is made out of fats itself

Question 24

What is the Golgi complex?

Answer 24

In the endoplasmic reticulum system, the Golgi complex packages products the rough endoplasmic reticulum makes, changing it slightly, and then transporting this to a cell that may need it.

So to summarise, the Golgi complex takes proteins that have been synthesised, changes it slightly, then packages it and sends it off to the cell needing this protein to either add to its function or structure (of the cell).
(Takes a letter, stamps it, and takes it off again)

Question 25

What is the mitochondria?

Answer 25

The mitochondria is the powerhouse of the cell. It creates the energy that makes cells work

Question 26

What are lysosomes?

Answer 26

Lysosomes are a waste disposal system. Bits of the cell will wear out and the lysosomes will act as a dustbin, with these parts of the cell that wear out will be sent to the lysosomes.
Examples include the mitochondria or bacteria will be sent to lysosomes as they wear out

Question 27

What is the cytoskeleton?

Answer 27

The cytoskeleton gives the cell structure and maintains shape of the cell. Inside the neurons it provides ‘rails’ to transport things made in the cell body.
This occurs during axonal transport. This is a two way railways
System that occurs when products being made inside the cell body travels from cell body, down the axon and to the end of the axon and things from the synapse can travel up the axon to the cell body

Question 28

What is axonal transport?

Answer 28

This is a two way railways system that occurs when products being made inside the cell body travels from cell body, down the axon and to the end of the axon and things from the synapse can travel up the axon to the cell body.
Involves the cytoskeleton which provides transport for things that are made in the cell body as well as giving the cell its structure and maintains its shape

Question 29

What are some components of cells that are in neurons and other cells in the body?

Answer 29

Nucleus, mitochondria, cytoskeleton and lysosomes, axonal transport occurring as a result. The endoplasmic system including the rough endoplasmic reticulum and the smooth endoplasmic reticulum. The Golgi complex too