Organisation of neurones Flashcards
Which property does not affect the function of the neurone?
a) shape of neurone and its processes
b) if it synapses or not
c) chemicals used to communicate with other neurones
d) the way the neurone reacts to neurotransmitters released by other neurones
b
What are multipolar neurones?
1 axon and lots of dendrites
What are motoneurons?
Carry signals from CNS to muscles and glands
What are bipolar sensory neurones?
1 axon and 1 dendrite
What are glial cells?
Nerve cells that do not carry nerve impulses
Functions of glial cells?
Digest dead neurones
Make myelin
Physical and nutritional support
3 types of glial cells in CNS and function?
Astrocytes - regulate ionic concentration
Oligodendrocytes - form myelin in CNS
Microglia - digest dead tissue
What is the difference between oligodendrocytes and Schwann cells?
Oligodendrocytes = myelin in CNS - myelin around several axons Schwann = myelin in PNS - myelin around 1 axon each
Silver impregnation method of staining on stains 1% of cells in a random manner - why is this an advantage when studying neurones?
Can study in isolation from neighbours.
The whole neurone shows up
Which of these is not a property of dendrites?
a) can have 1 to several
b) emerge from the cell body
c) divide into secondary and tertiary dendtires
d) can be covered in spines
e) do not taper with distance from soma
e - they do taper
Which of these is not a property of axons?
a) emerge from the general cell body
b) does not taper
c) each neurone has 1 axon
a) emerges from the axon hillock
What cells regulate motor movements in the cerebellum?
Purkinje cells
What is the function of the cerebellum?
Autonomic motor tasks - balance
Intergates visual and proprioceptive inputs
Decides which muscles need to be contacted
Why does myelin increase speed of transduction?
Made of lipids and proteins so ions cannot pass through = saltatory conduction
What is an axodendritic connection?
Between axon terminal and dendrite
What is an axoaxonix connection?
Between 2 axon terminals
What is an axiomatic connection?
Between axon terminal and soma
What is the function of axonal transport?
Transports replacement mitochondria, Golgi secretions, membrane components along prolonged axons using microtubules
What are the 3 types of axonal transport?
Fast anterograde, slow anterograde, fast retrograde
Which direction is fast anterograde transport?
From soma to synpase
What types of neurones require fast anterograde transport?
Active neurones that need quick replacement
What proteins does fast anterograde transport use?
Microtubules and kinesin
What is slow anterograde axonal transport?
Movement of soluble substances along axon at 2 different rates
What is type A slow anterograde transport?
Components of cytoskeleton synthesis along axon
What is type B slow anterograde transport?
Smaller protein molecules like actin, myosin (faster)
What direction is fast retrograde axonal transport?
From synapse to cell body
What protein does fast retrograde transport use?
Microtubules and dyein
What is the fate of the returned matter from fast retrograde transport?
Reused in chemical synthesis or rebuilding of organelles
Disposed of
What is a disadvantage of fast retrograde transport?
Carrys toxins and viruses into CNS e.g. rabies
