NBBS - organisation of nervous system Flashcards
What does it mean by neurons being polarised?
Information only flows in one direction
What is the resting membrane potential in neurons?
-70mV
How much is transmission delayed at synapses?
0.3-0.5ms
What determines the output of a synapse?
the receptor (not neurotransmitter)
What is white matter?
myelinated axons
What is grey matter?
cell bodies, dendrites, axons
How is grey matter organised?
nuclei, ganglia and layers
What do layers in grey matter allow?
spatially distributed info (map), and modularity
What do nuclei allow?
group of cells with similar functions to maximise efficiency
What are double cortex syndrome and lissencephaly?
cortex layering diseases
What layer of the cortex are projection neurons in?
layer 5
Are projected neurons myelinated?
yes
What part of the CNS do motor neurons exit?
ventral side
What part of the CNS do sensory neurons enter?
dorsal side
Where does the SNS arise from?
thoracic spinal cord
Where does the PNS arise from?
cranial and sacral
What cells are made in the neural crest?
peripheral nervous system
How are CNS cell type differentiated?
by their dorso-ventral position in the neural tube
Where do CNS cells arise from in the neural tube?
inner ventricular surface
How do neurons migrate in development?
radial and tangenital migration
What is the role of radial cells?
- scaffold in adults
- projenitor cells in development & guide migrating neurons
- source of astrocytes in brain injury
What are the roles of astrocytes?
- blood brain interface
- homeostasis
- removal of excess K+ at nodes
- insulation of synapse
- removes neurotransmitter in synapse
What are reactive astrocytes?
they can form glial scars and trigger epilepsy
What are the four features of the cerebral cortex?
- regional specialism
- distributed networks
- asymmetry
- maps
How are regions of the cortex named?
according to the overlying bones
What are the lobes of the cortex?
frontal, temporal, parietal, occipital
What is the frontal lobe responsible for?
motor and congnition
What is the temporal lobe responsible for?
hearing
What is the parietal lobe responsible for?
sensory
What is the occipital lobe responsible for?
vision
What is the central sulcus?
landmark separating frontal lobe/motor control and parietal/sensory control
What is an example of asymmetry in the cortex?
interpretation of reading
What are the features of cortical maps?
ordered, disproportionate representation, plastic
Where does learning prediction occur?
thalamus
What areas are responsible for recording value of behaviour?
basal ganglia = reward
cerebellum = error
What are the 2 parts of the cranium?
neurocranium and viscerocranium
What are the bones of the neurocranium?
frontal, ethmoidal, sphenoidal, occipital, temporal, parietal
Which neurocranium bones are paired?
temporal and parietal
What are the bones of the viscerocranium?
mandible, vomer, maxillae, inferior nasal connchae, zygomatic, palatine, nasal, lacrimal
What is the only moveable joint in the cranium?
temporomandibular joint
What are the main brain regions?
cerebral hemisphere, thalamus, hypothalamus, cerebellum, brainstem
What are the layers of the meninges from outer to inner?
dura mater, arachnoid mater, pia mater
What is the main supply to the meninges?
Middle meningeal artery
branch of maxillary artery
How does the middle meningeal artery enter the cranium?
through the foramen spinosium
- runs behind the pteriun where the skull is very thin
Where is CSF produced?
in the ventricles
How does CSF exit the ventricles?
openings in the roof of the 4th ventricle
Where is CSF reabsorbed?
arachnoid granulations via sinuses
