1 - Topography of the Nervous System Flashcards
What are the different components of the CNS and the PNS?
- CNS cannot regenerate but PNS can
- Cauda equina made up of dorsal and ventral roots
What is white and grey matter?
Grey: cell bodies and dendrities. Highly vascularised as metabolically active. In brain there is extra layer of grey matter on outside
White: made of axons and connects grey areas together. Fatty myelin makes it white
In the PNS grey matter is ganglion and white matter is peripheral nerve.
Define the following 3 terms relating to divisions of white matter in the spinal cord:
- Funiculus
- Tracts
- Fasiculus
Funiculus: a segment of white matter which contains axons going up and down the spinal cord
Tracts: connection between two areas of grey matter where the axons are only running in one direction
Fasiculus: subdivision of a tract which supplies a distinct region of the body
How is grey matter in the spinal cord split up?
- Into cell columns called Rexed’s laminae
- Motor neurones supplying a given muscle arise from multiple segments and form a nucleus
What is the definition of a fibre in the CNS and what are the three different types of fibre?
- Fibre: axon in association with its supporting cell e.g oligodendrocyte
- Association fibres connect the same hemisphere, commisural connect right and left hemisphere and projection connect cerebral hemispheres with cord/brainstem
What is a nucleus?
A collection of nerve cell bodies
What is the difference between dorsal and ventral roots?
- Dorsal: sensory
- Ventral: motor
What are the colliculi?
Reflex centre in the midbrain for rapid responses to sound and vision, e.g orientate head towards explosion
What are the functions of the brain stem?
What are the main sulci in the brain and their significance? e.g central
What is the function of the following and where on the inferior aspect of the brain are they located?
- Optic Chiasm
- Uncus
- Medullary Pyramids
- Parahippocampal Gyrus
What is the function of the following:
- Corpus Callosum
- Thalamus
- Cingulate Gyrus
- Hypothalamus
What is the function of the following:
- Fornix
- Tectum
- Cerebellar Tonsil
Where is CSF made, stored and reabsorbed?
- Made in the choroid plexus found in ventricles
- Has metabolic, immune and mechanical protection functions
- Circulates in ventricles and subarachnoid space then reabsorbed at arachnoid granulations
Draw and explain the ventricular system of the brain.