1.1 intro and basic topography Flashcards
What are the basic components of the cns?
Cerebral hemispheres
Brainstem and cerebellum
Spinal cord
What are the basic components of the pns?
Dorsal and ventral roots
Spinal nerves
Peripheral nerves
True or false: because the Cauda equina lies in the cranial cavity, it is in the central nervous system.
False
Cranial cavity doesn’t automatically mean its in the cns
What is grey matter composed of?
Cell bodies and dendrites, its highly vascular
In the central nervous system
( has some axons to communicate with white matter)
In PNS = grey matter = ganglion = collection of cell bodies
What is white matter composed of and why is it white?
It’s composed of axons
(Myelinated and unmylinated) It’s white because of the presence of fatty myelin
In the PNS is termed a nerve or root.
What is the pns equivalent of grey and white matter?
Grey after = ganglion (connecting cell bodies) was
Whit matter = peripheral nerve
What is the basic structure of a spinal cord segment?
- 31 segments each supplying a dermatome and myotonic on each side
- central grey matter and outer white matter
- connects with a spinal nerve through dorsal sensory and ventral motor roots
- if you know the dermatome/myotome, you can localise the lesions to a given cord segment
What type of matter makes up the cerebral cortex?
Grey matter
What is a funiculius?
A segment of white matter containing multiple distinct tracts. Impulses travel in multiple directions
What is a tract of white matter?
An anatomically and functionally defined white matter pathway connecting two distinct regions of grey matter. Impulses travel in one direction (either ascending or descending)
This is how white matter is arranged
What is a fasciculus of white matter?
A subdivision of a tract supplying a distinct region of the body.
How is grey matter arranged?
Into cell columns
What is a nucleus of grey matter?
A collection of functionally related cell bodies
What is a cortex of grey matter?
A folded sheet of cells bodies found on the surface of a brain structure.
What is a fibre of white matter?
A term relating to an axon in association with its supporting cells. Used synonymously with axon.
- association fibres connect cortical regions with the same hemisphere e.g U fibres
- commissary fibres connect left and right hemispheres, or cord halves e.g the corpus callosum
- projection fibres connect the cerebral hemispheres with the cord/brainstem and vice versa