1. Topography Flashcards
What is grey matter composed of?
Cell bodies and dendrites
Highly vascularised
What is white matter composed of?
Axons with their supporting cells
What is a nucleus in grey matter?
Collection of functionally related cell bodies
What is the cortex in grey matter?
Folded sheet of cell bodies found on the surface of a brain structure (1-5mm thick)
What are fibres in white matter?
An axon in association with its supporting cells
What are association fibres?
Connect cortical regions within same hemisphere
What are commissural fibres?
Connect left and right hemispheres or cord halves
What are projection fibres?
Connect cerebral hemispheres with cord/brainstem and vice versa
What is the midbrain generally responsible for?
Eye movements and reflex responses to sound and vision
What is the pons function?
Feeding
Sleep
What is the medulla function?
Cardiovascular and respiratory centres
Contains a major motor pathway
What does the precentral gyrus contain?
Primary motor cortex
What does the post central gyrus contain?
Primary sensory cortex
What is the optic chasm?
A site where fibres in the visual system cross over
What is the uncus?
Part of the temporal lobe that can herniate, compressing the midbrain
Important olfactory role
What is the parahippocampal gyrus?
Key cortical region for memory encoding
What is the cingulate gyrus?
Cortical area important for emotion and memory
What is the fornix?
Major output pathway from hippocampus
What is the tectum?
Dorsal part of the midbrain involved in involuntary responses to auditory and visual stimuli
What is the cerebellar tonsil?
Part of cerebellum that can herniate and compress the medulla
How much CSF is produced by the choroid plexus per day?
600-700ml
Where is CSF produced?
Choroid plexus in each of the ventricles
Describe the route of CSF after it is produced
Most produced in lateral ventricles
From there, CSF circulates through interventricular foramen into third ventricle
CSF drains from third ventricle to fourth ventricle via cerebral aqueduct
Then drains from fourth ventricle into subarachnoid space via lateral and median apertures
CSF moves around superficial surfaces of brain and spinal cord before being reabsorbed in granulations
How many segments are there in the spinal cord?
Around 31
What does each segment of the spinal cord connect to?
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 grey matter
Impulses travel in one direction
What is a fasciculus?
A subdivision of a tract supplying a distinct region of the body
