Neurones - Cells and Tissues of the nervous system Part 2 Flashcards
A = white matter
B = grey matter
What is grey matter?
neuronal cell bodies
What is white matter?
myelinated axons
Where are cell bodies found?
grey matter
Why is the white matter white in appearance?
myelin is a membrane which is mostly fat, which appears white
Name A and B
A = grey matter
B = white matter
A = neurone
B = nissl bodies (granular appearance)
What is the white empty space around the axon?
myelin sheath
How is white matter arranged?
tracts
What are tracts?
specific bundles of axon carrying specific information to a specific part of the brain or periphery
myelinated axons carrying information
Where does the sensory information reach the white matter? (dorsal or ventral root)
dorsal root
What information does the dorsal root ganglia convey?
sensory information
Where does the sensory information go?
white matter tracts
Is the dorsal tract an ascending or descending tract?
ascending tract, it carries information up to the spinal cord to the brain where it goes to a specific part of the brain
What information is they grey matter conveying?
motor information (efferent)
What tract is the motor movement of walking pass through?
lateral corticospinal tract
What is this tract called and what does it convey?
lateral corticospinal tract
motor information from brain to limb
What nerve goes to the lower limb?
sciatic nerve
What information does the ventral ganglia convey?
motor
Where does the motor information synapse?
in the grey matter
Where does the motor neuronal cell body lie?
in the grey matter, they synapse there
After synapsing in the grey matter, where does the motor signal (walking) continue?
the ventral root, through the sacral plexus to the sciatic nerve and goes and supplies muscles of lower limb
What information do descending tracts convey?
motor information
What is the difference between the dorsal and ventral root?
dorsal = sensory
ventral = motor
Name A and B
A = dorsal
B = ventral
What type of neurone will the ventral root have?
multipolar neurone
Where is the cell body of a sensory neurone?
in the ventral hall of the spinal cord
sensory neurone
Name A and B
A = grey matter
B = white matter
Why is grey matter grey?
high proportion of non-myelinated cell bodies
What passes through the white matter?
fibre tracts
What is the role of white matter tracts?
connect cerebral hemispheres
connect the brain with lower centres
of periphery
What is a collection of grey matter inside the cerebral hemisphere?
nucleui/nucleus
What type of neuron are sensory neurons?
pseudounipolar
What is the name given to a collection of neuronal cell bodies outside of the CNS?
ganglion
Where does the pseudouniplar nerve synapse?
spinal cord
What is the name given to fibre pathways and is it grey or white?
white matter up
grey matter down
What is the collection of white matter in the spinal cord called?
tract
What do you call the collection of cell bodies inside the CNS? (4)
nucleus
What do you call the collection of cell bodies inside the spinal cord?
central grey matter of the spinal cord
What matter is the AP passing through and what matter does it eventually reach?
through white matter tract in the brain
reaching grey matter on the periphery of the brain
What type of neurone will relay the signal here?
multipolar neurone
Does a motor signal pass through the ventral or dorsal horn of the spinal cord?
ventral horn and to the muscle
