CNS structure and functions Flashcards
what percentage of the body’s oxygen des the brain use
25%
what percentage of the body’s glucose does the brain use
50%
what is the CSF
a shock absorbing medium used to exchange nutrients and waste
where is the CSF formed
in the choroid plexus
which cells in the choroid plexus secrete CSF
non-cilated ependymal cells
what is hydrocephalus
a build up of CSF in the brain causing pressure
what is communicating hydrocephalus
failure to absorb CSF
what is non-communicating hydrocephalus
failure to circulate CSF to subarachnoid space
what do astrocyte foot processes do
secrete paracrines that promote tight junction formation
4 lobes of the telencephalon cerebral cortex
frontal lobe
parietal lobe
occiptal lobe
temporal lobe
whats the frontal lobe used for
reasoning planning speech movement emotions problem-solving ( found in the front of central sulcus)
what is the parietal lobe used for
touch pressure temperature pain ( found behind central sulcus)
what is the occipital lobe used for
vision (found behind temporal and parietal lobes)
what is the temporal lobe used for
perceiving and recognising auditory stimuli (sound) and memory (found between the lateral fissure)
the three specialisations of telencephalon
- senosry areas- for sensory input
- motor areas- for skeletal muscle moveent
3 association areas- for voluntary moveemnt and info b/w sensory and motor
what is the blood brain barrier formed by
capillary endothelial cells joined by tight junctions
what does the BBB prevent entry of
neurotoxins and drugs into the brain by active transport mediated by p-glycoproteins
what do endothelial cells allow diffusion of
small hydrophobic molecules e.g. CO2, O2, hormones
where is the primary somatosensory cortex located
in post central gyrus
what is the somatosensory hormunuculus
caricature of corticol tissue devoted to each senosry function
where is the primary motor cortex located
in precentral gyrus
what does the primary motor cortex do
controls voluntary movement
what is the motor homunculus
caricature of corticol tissue devoted to each motor function
what is the limbic system used for
motivation learning memory
what are the parts of the limbic system
cingulated gyrus
hippocampus
amygdala
what does the cingulated gyrus do
coordinates sensory inputs with emotions, emotional responses to pain
what does the hippocampus do
sends memories out to right part of cerbral hemisphere for long-term storage and retrieve them when necessary
what does amygdala do
involved in emotional responses and linking emotions with memory
what does basal nuclei do
controls fine movements, reward and motivation
helps with posture
controls behaviour habits
what does the diencephalon- thalamus do
co-ordinates the activities of the cerabral cortex and basal nuclei
what does the diencephalon-hypothalamus do
receives signals ans sends them to sympathetic and parasympathetic nervous system
sends neural and hormonal outputs to pituitary
what does the midbrain control
visual system
auditory system
eye movement
what do red nucleus and susbtantia nigra do
control body movement
what does the degeneration of neurons in the substantial nigra cause
parkinsons disease
what 2 things is the midbrain comprised of
tectum
tegmentum
what does the tectum do
responsible for the auditory/ visual reflexes
2 parts of the tectum
- superior colliculi- top part controlling visual reflex
2. inferior colliculi- bottom part controlling auditor reflex
what are the 5 parts of the tegmentum
- periaqueductal gray
- substantia nigra and amp; red nucleus
- ventral tegmental area
- raphe nuclei
- locus coeruleus
what does the periaqueductal gray do
deals with pain and fear
what does the ventral tegmental area do
deals with reward and addiction
what does the raphe nuclei do
deals with mood and depression
what does the locus coeruleus do
deals with anxiety
what are the three types of hindbrain cerebellum
- vestibulocerebellum
- spinocerebellum
- cerebrocerebellum
what is the vestibulocerebellum used for
balance and eye movement
what is the spinocerebellum used for
muscle tone and controls voluntary movement
what is the cerebrocerebullum used for
planning and initiating voluntary activity
what is the hindbrain pons and medulla used for
relaying information between the brain and spinal cord
what is the pons used for
acts as a motor/sensory relay centre
supports respiration
maintains our sleep-wake cycle
what is the medulla used for
useful in cardiac and respirator rhythm
reticular formation begins in the medulla oblongata
what does the hindbrain reticular activating system do
controls the degree of corticol alertness/ level of consciiousness
