Lesson 1 - Properties Of Neurons Flashcards
In the brain there are two broad classes of cells which are joined together to form normal functioning brain tissue. What are they?
Neurons, the nerve cells that send and receive signals.
Glia, cells that provide structure in the brain
In every brain there are two broad classes of cells that are joined together to form the normal functioning brain tissue. They are?
Neurons and Glia cells
How many neurons are there in the human brain? And how long do you carry them for?
Around 100 billion.
You carry the, for the rest of your life, they don’t really die off.
Where can you find Glial cells or Neuroglia?
They are important and found in some areas of the brain like the thalamus, they outnumber neurons by 10:1
What fraction of all neurons in the brain are found in the cerebellum?
4/5 of all neurons in the brain are found in the cerebellum
What’s the function of the cerebellum?
The cerebellums function is for motor control, such as balance and movement
What can you find in neurons that can also be found in cells in the rest of your body?
A plasma membrane (holds everything together), a nucleus and mitochondria, and a Golgi complex.
What can’t you find in the rest of your cells in your body that you can find in neurons?
The axon, synapse, and dendrites
What’s the function of an axon?
The axon connects the neurons to other parts of the nervous system
What’s the axon hillock?
Where the cell body tapers to become the axon. Axon emerges from the cell body, giving rise to the axon.
Also referred to as the initial segment
How long is the axon? And how far can it travel?
Distances ranging from microns to metres
can travel 3 metres to get to the spinal cord
The axon varies in how long it is.
What is the axonal membrane?
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
What is the function of the synapse?
The synapse connects with the next cell in the chain
Acts 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
What’s the function of dendrites?
Dendrites receive inputs from other parts of the nervous system.
What does a dendrite look like?
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
What does the dendritic arbour or spines help with?
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
What are spines?
Have small fibres inside (2 microns) and contain filaments made of actin and are components of muscle.
the spines are constantly changing shape so other cells coming into the cell are constantly changing.
What will affect the impact that spines or dendrites have on the cell that is receiving the input?
The size and width of the top part of the spine
The brain is constantly ___ as it is a very _____ system
Changing, dynamic
What is a nucleus?
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
What is the rough endoplasmic reticulum?
In the endoplasmic system, the rough endoplasmic reticulum
Takes the DNA and synthesises proteins from nucleus, adding to the function or structure of the cell
What is the smooth endoplasmic reticulum?
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)
So to summarise, what does the rough endoplasmic reticulum do? And what does the smooth endoplasmic reticulum do?
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
What is the Golgi complex?
the Golgi complex packages proteins the rough endoplasmic reticulum makes, changing it slightly, and then transports this to a cell that needs 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)
What is the mitochondria?
The mitochondria is the powerhouse of the cell. It creates the energy that makes cells work
What are lysosomes?
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
What is the cytoskeleton?
Maintains shape and structure of the cell.
Inside 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
What is 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.
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
What are some components of cells that are in neurons and other cells in the body?
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
What does the dendritic arbour do?
increases area of dendrites allowing for more processes
