Intro to Nervous System Flashcards
Is the cerebral cortex grey or white matter?
Grey matter
Is the corpus callosum grey or white matter?
White matter
What is grey matter composed of?
Cell bodies and dendrites, where all the synapses are
What is white matter composed of?
Axons and their supporting cells - connects grey matter
Why is white matter white?
Due to the presence of myelin (fatty)
What is the PNS equivalent of grey matter?
Ganglion
What is the PNS equivalent of white matter?
Peripheral nerve
How many segments is the spinal cord composed of?
31
Describe the distribution of grey/white matter in the cord
Central core of grey matter and an outer shell of white matter
Describe the distribution of grey/white matter in the brain
Central core of grey matter, surrounded by white matter, outer shell of grey matter
Is the dorsal root sensory or motor?
Sensory
Is the ventral root sensory or motor?
Motor
What is a funiculus?
A segment of white matter containing multiple distinct tracts - impulses travel in multiple directions
What is a tract?
Unidirectional connection between two regions of grey matter
What is a fasciculus?
A subdivision of a tract supplying a distinct region of the body
How is grey matter in the cord organised?
Into cell columns - Rexed’s laminae
What is a nucleus?
A collection of functionally related cell bodies (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?
An axon in association with its supporting cells (white matter)
What are association fibres?
Fibres that connect cortical regions within the same hemisphere
What are commissural fibres?
Fibres that connect left and right hemispheres or cord halves
What are projection fibres?
Fibres that connect the cerebral hemispheres with the cord/brainstem and vice versa
What does the precentral gyrus contain?
Primary motor cortex
What does the postcentral gyrus contain?
Primary sensory cortex
What does the primary visual cortex surround?
Calcarine sulcus
Where is the site of olfactory cortex?
Uncus of temporal lobe
Where is the key cortical region for memory encoding?
Parahippocampal gyrus
What is the optic chiasm?
A site where fibres in the visual system cross over
Where is the cortical area important for emotion and memory?
Cingulate gyrus
What is the fornix?
Major output pathway from the hippocampus
What is the tectum?
Dorsal part of the midbrain involved in involuntary responses to auditory and visual stimuli
How is CSF reabsorbed?
Circulates through ventricular system and subarachnoid space before being reabsorbed at the arachnoid granulations into venous blood via venous sinuses
