Session 1 - Basic Topography Flashcards
What are the basic components of the central nervous system?
Cerebral hemispheres
Brainstem and cerebellum
Spinal cord
What are the basic components of the peripheral nervous system?
Dorsal and ventral roots
Spinal nerves
Peripheral nerves
Is everything within the vertebral column part of the CNS?
No, the cauda equina is made up of dorsal and ventral roots, which are part of the PNS.
Are grey and white matter found in the peripheral nervous system?
No, the terms grey and white matter are only used with respect to the central nervous system.
What is grey matter composed of?
Cell bodies and dendrites.
Highly vascular.
What is white matter composed of?
Axons (with their supporting cells).
Which type of matter is more myelinated; white or grey?
White matter is more myelinated than grey matter. It is white due to the presence of fatty myelin.
What can be seen as the PNS equivalent of grey matter?
Ganglions
What is a ganglion?
A group of cell bodies found in the peripheral nervous system.
Why is the term basal ganglia misleading?
The word ganglia suggests that it is a group of cell bodies in the PNS, but basal ganglia are CNS structures.
What can be seen as the PNS equivalent of white matter?
Peripheral nerves
At what vertebral level does the spinal cord become the cauda equina?
L1/2
Describe the arrangement of white and grey matter in the spinal cord.
The cord has a central core of grey matter and an outer shell of white matter.
The spinal cord is composed of around how many segments?
31 segements
Each segment of the spinal cord connects to a spinal nerve through what roots?
Dorsal (sensory) roots and ventral (motor) roots
What is a funiculus?
A segment of white matter containing multiple distinct tracts. Impulses travel in multiple directions.
E.g. the dorsal funiculus
What is a tract?
An anatomically and functionally defined white matter pathway connecting two distinct regions of grey matter. Impulses travel in one direction.
E.g. the dorsal column tract.
What is a fasciculus?
A subdivision of a tract supplying a distinct region of the body.
E.g. the fasciculus gracilis and fasciculus cutaneous in the dorsal column tract.
What are the three funiculi in the spinal cord?
Dorsal funiculus
Lateral funiculus
Ventral funiculus
What is a nucleus?
A group of functionally related cell bodies found in the CNS.
Is a nucleus grey or white matter?
Grey matter
What is the cortex?
A folded sheet of cell bodies found on the surface of the brain. Grey matter.
What is a fibre?
A term relating to an axon in association with its supporting cells (e.g. oligodendrocytes or Schwann cells). Used synonymously with ‘axon’. White matter.
What are association fibres?
Axons connecting cortical regions of the brain within the same hemisphere.
What are commissural fibres?
Axons connecting the left and right hemispheres. E.g. corpus callosum
What are projection fibres?
Axons connecting the cerebral hemispheres with cord/brain stem and vice versa.
What are the three parts of the brainstem and what are they mainly responsible for?
Midbrain (mesencephalon):
- eye movements and reflex responses to sound and vision
Pons:
- feeding
- sleep
Medulla:
- cardiovascular and respiratory centres
- contains a major motor pathway (medullary pyramids)
Which gyrus contains the primary motor cortex?
Precentral gyrus
Which gyrus contains the primary sensory cortex?
Postcentral gyrus
The primary visual cortex surrounds which sulcus?
Calcarine sulcus
Where is CSF produced?
Choroid plexuses found in the brain ventricles.
Where is CSF reabsorbed?
Arachnoid granulations (and some other sites)
