Flashcards in Basic Topography Deck (45):
Where is the hippocampus found?
Which cranial N emerges ventrally from the ponto-medullary junction?
The superior colliculus is part of which structure?
Outline the motor homunculus
Medial - lower limbs
Intermediate - hands
Lateral - face
Which part of the brainstem lies at the level of the tentorium cerebelli?
Bridging veins transverse which space?
What does the CNS encompass?
Brainstem and cerebellum
What does the PNS encompass?
Dorsal and ventral roots
What is grey matter?
Composed of cell bodies and dendrites and synapses
Highly vascular (reflects its ‘computational’ role)
What is white matter?
Composed of axons (supporting cells)
White due to fatty myelin
Define basal ganglia
A group of subcortical structures known to be involved in motor function
What is the PNS equivalent of grey matter?
What is the PNS equivalent of white matter?
Describe the white and grey matter structure of the brain
Like the cord
Central grey matter surrounded by white matter then surrounded by extra layer of grey matter
Describe a spinal cord segment?
Cord has a central core of grey matter and an outer shell of white matter
Each segment connects with a spinal (mixed) N through dorsal (sensory) and ventral (motor) roots
Dorsal N root has a swelling = spinal ganglion
How can symptoms relate to spinal cord lesions?
Sensory and motor = mixed = lesion in spinal nerve
Just sensory = lesion in dorsal root
Just motor = lesion in ventral root
Segment of white matter containing multiple distinct tracts – axons up/down
Impulses travel in multiple directions
3 in the CNS = dorsal, ventral, lateral
Connection between 2 regions of grey matter
An anatomically and functionally defined white matter pathway connecting two distinct regions of grey matter.
Impulses travel in one direction
A subdivision of a tract supplying a distinct region of the body
Describe how the grey matter is divided?
Collection of functionally related cell bodies
Folded sheet of cell bodies found on the surface of the brain
Define fibre (white matter)
Axon with its supporting cells
Association = connects regions in the same hemisphere
Commissural = connect L and R hemispheres (corpus callosum)
Projection = connect cerebral hemispheres with cord/brainstem
What is the role of the midbrain?
Reflex responses to sound and vision
What is the role of the pons?
What is the role of the medulla?
Cardiovascular and respiratory centres
Contains major motor pathways – medullary pyramids
What is the central sulcus?
Sitting in the coronal plane
Key landmark separating frontal and parietal lobes
What is the precentral gyrus?
Contains primary motor cortex
What is the postcentral gyrus?
Contains primary sensory cortex
What is the lateral fissure?
Separates the temporal from the frontal/parietal lobes
What is the parieto-occipital sulcus?
Separates parietal from occipital lobe
What is the calcarine sulcus?
Primary visual cortex surrounds this
Describe the optic chiasm
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
Describe the medullary pyramids
Location of descending motor fibres (each has 1 million)
Describe the parahippocampal gyrus
Key cortical region for memory encoding
What is the corpus callosum?
Fibres connecting the two cerebral hemispheres
Describe the thalmus
Sensory station projecting to sensory cortext
What is the role of the cingulate gyrus?
Cortical area important for emotion and memory
What is the role of the hypothalamus?
Essential centre for homeostasis
Describe the fornix
Major output pathway from the hippocampus
Describe the tectum
Dorsal part of the midbrain involved in involuntary responses to auditory and visual stimuli
What can happen to the cerebellar tonsil?
Part of the cerebellum that can herniate and compress the medulla
What are the ventricles of the brain?
Contain choroid plexus which makes 600-700ml of CSF per day