1.1 The Basics Flashcards
What does the CNS consist of?
Cerebral hemispheres
Brainstem and Cerebellum
Spinal cord
What does the PNS consist of?
Dorsal and Ventral roots
Spinal Nerves
Peripheral nerves
What is the difference between grey and white matter?
Grey matter is composed of cell bodies and dendrites and it highly vascular.
White matter is composed of axons. (Grey matter also contains axons to allow it to communicate with white matter).
What is the PNS equivalent of grey matter?
A ganglion
What is the PNS equivalent of white matter?
Peripheral nerves
Why is white matter white?
Due to the presence of fatty myelin.
What is a segment of the spine?
The cord is split into around 31 segments, each supplying a given dermatome and myotome on each side.
They each connect with a spinal (mixed) nerve through dorsal (sensory) and ventral (motor) roots.
What is a funiculus?
A segment of white matter containing multiple distinct tracts. Impulses travel in multiple directions.
What is a tract?
An anatomically and functionally defined white matter pathway connecting two distinct regions of gray matter. Impulses travel in one direction.
What is a fasciculus?
A subdivision of a tract supplying a distinct region of the body.
What are Rexed’s laminae?
The names of the cell column that divide grey matter.
The motor neurone supplying a given muscle arise from multiple segments and form a distinct population of neurones in the CNS - a nucleus.
What is the ventral horn?
Where motor neurones reside that supply skeletal muscles.
Define nucleus (grey matter)
A collection of functionally related cell bodies.
Define cortex (grey matter)
A folded sheet of cell bodies found on the surface of a brain structure. Typically 1-5mm thick.
Define fibre (white matter)
A term relating to an axe in association with its supporting cells (e.g. oligodendrocytes). Used synonymously with ‘axon’.