1.1.1 Background and basic terminology Flashcards
What are the basic components of the CNS?
Cerebral hemispheres
Brainstem and cerebellum
Spinal cord
Derived from neural tube
What are the basic components of the PNS?
Dorsal and ventral roots
Spinal nerves
Peripheral nerves
Cranial nerves (I and II are CNS)
Cauda equina (has dorsal and ventral roots, not spinal cord)
Primarily derived from neural crest cells
What happens when a spinal nerve becomes stretched?
Certain injuries can cause spinal nerves to become stretched, as spinal nerves repair poorly damage can be long-lasting
What are the two different matters within the CNS?
Grey matter
White matter
What is grey matter made of?
Composed of:
* Cell bodies
* Dendrites
Highly vascular structure which reflects its computational role (how we understand)
What is white matter made of?
Composed of axons with their supporting cells
What causes the appearance of grey and white matter?
Grey- less myelin, more blood vessels
White-lots of axons, myelination is lipid based- the fat gives it the white colour
Does grey matter have axons?
Yes, does not have as much as the white matter, axons are used to communicate with white matter
What is the PNS equivalent of grey and white matter?
Grey matter- ganglion (collection of cell bodies)
White matter- peripheral nerve
What is the difference between oligodendrocytes and schwann cells?
Oligodendrocytes are responsible for myelination within the CNS and can myelinate mutliple axons
Schwann cells are responsible for myelination in the PNS, can only myelinate single axons
What is a nucelus within the CNS?
Collection of functionally related cell bodies
Grey matter structure
What is a cortex within the CNS?
Folded sheet of cell bodies found on the surface of a brain structure
Typically 1-5mm thick
Grey matter structure
What is a fibre within the CNS?
Axon in association with its supporting cells same meaning as ‘axon’
White matter structure
What are the 3 types of fibres found within the CNS?
Association fibres
Commissural fibres
Projection fibres
What do association fibres do?
Connect cortical regions within the same hemisphere
Does not cross the midline