CNS structure and function Flashcards
what percentage of the body’s oxygen does 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-ciliated 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
what are the four lobes of the telencephalon cerebral cortex?
- Frontal Lobe
- Parietal Lobe
- Occipital Lobe
- Temporal Lobe
what is the frontal lobe used for?
used for reasoning, planning, speech, movement, emotions, problem-solving
(found in 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 below the lateral fissure)
what are the three specialisations of the telencephalon?
- Sensory areas - for sensory input
- Motor areas - for skeletal muscle movement
- Association areas - for voluntary movement 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 blood brain barrier prevent the entry of?
neurotoxins and drugs into the brain by active transport mediated by p-glycoproteins
what do endothelial cells allow the diffusion of?
-small hydrophobic molecules e.g. CO2, O2, hormones
where is the primary somatosensory cortex located?
in the postcentral gyrus
what is the somatosensory homunculus?
caricature of cortical tissue devoted to each sensory function
where is the primary motor cortex located?
in the precentral gyrus
what does the primary motor cortex do?
controls voluntary movements
what is the motor homunculus?
caricature of cortical 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 cerebral hemisphere for long-term storage and retrieving them when necessary.
what does the amygdala do?
involved in emotional responses and linking emotions with memory
what does the 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 cerebral cortex and basal nuclei
what does the diencephalon - hypothalamus do?
- receives signals and 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 the red nucleus and substantia 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
2. Tegmentum
what does the tectum do?
responsible for the auditory/visual reflexes
what are the 2 parts of the tectum?
- superior colliculi - top part controlling visual reflex
2. inferior colliculi - bottom part controlling auditory reflex
what are the 5 parts of the tegmentum?
- periaqueductal gray
- substantia nigra & 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 respiratory rhythm
- reticular formation begins in the medulla oblongata
what does the hindbrain reticular activating system do?
controls the degree of cortical alertness/level of consciousness
