structure and function of CNS Flashcards
what makes up the CNS?
spinal cord and brain
what makes up the peripheral nervous system?
spinal nerves, cranial nerves
what cell types are found In the CNS?
neurons
glial cells
astrocytes
Schwann cells
oligodendrocytes
ependymal cells
microglia
function of astrocytes?
give structural support, form blood brain barrier, nourish, nutrient supply to neurons in the CNS
function of ependymal cells?
found in ventricles of brain, promote circulation of cerebrospinal fluid
function of microglial cells?
immune protection, defence role ; phagocytic
function of oligodendrocyte and Schwann cells?
enables fast signalling (myelination) and neural support
what promotes myelination?
CNS - glial cells, oligodendrocytes
PNS - Schwann cells
what makes the tissue more white?
more axons (myelinated), more glial cells (oligodendrocytes),; blood vessels
what makes the tissue more grey?
more cell bodies, dendrites, axon terminals, glial cells (astrocytes) ; blood vessels
what are sulci?
grooves (central sulcus and lateral sulcus)
what are gyri?
ridges (pre central gyrus and post central gyrus)
what are the lobes of the brain?
-frontal
-parietal
-temporal
-occipital
what is the function of the brain stem?
consciousness, breathing and heart rate
what is the function of the cerebellum?
balance/posture
coordination of movement
what is the function of the cerebrum?
speech, judgments, emotions, learning act
what are the 3 parts of the brain stem?
midbrain
pons
medulla oblongata
where do most of the cranial nerves emerge from?
the brain stem
what is the function of prefrontal cortex?
problem solving, high level of thinking, personality, moods, behaviours
what is the function of the primary motor cortex?
controlling voluntary movement
what is the function of the primary somatosensory cortex?
sensation and touch
which part of the brain controls hearing?
temporal lobe
which part of the brain controls speech?
brocas area (in the frontal lobe)
which part of the brain controls language and reading?
wernicke’s area (temporal lobe)
what is the limbic system?
emotions and emotional behaviour (amygdala) ; learning and memory (hippocampus)
what is the basal ganglia?
control of movement
what is the hypothalamus?
temp regulation; other homeostasis
what is the thalamus?
sensory relay centre between spinal cord and cerebral cortex
what is a white matter tract?
communication between brain parts
which hemisphere is language production and comprehension in?
the left (97% of people)
what is the spinal cord?
a direct extension of the brainstem downwards
how are the spinal nerves named?
after the vertebrae that they exit
what are nerves C1-C5 involved in?
breathing
what are nerves L3-S1 involved in?
knee and foot movement
where is the sympathetic tone?
T1-T12
where is the parasympathetic?
cranial nerves & S4
where is the motor output?
spinal nerve on the anterior side
where is the sensory input?
spinal nerve on dorsal side
what are tracts?
bundles of nerve fibres that run up/down the spinal cord. some are ascending and descending
what is the spinothalamic tract?
ascending, sensory, pain and temp
what is the corticospinal tract?
descending, motor, voluntary movement
what are the three membranes that surround the brain and spinal cord (meninges)?
-dura mater (hard/tough)
-arachnoid mater (spider)
-pia mater (gentle)
what is the dura mater?
fibrous connective tissue
what is the arachnoid mater?
membrane, does not pass into the sulk and presses against dura
what is the Pia mater?
innermost layer of meninges, allows blood vessels to pass through brainmembrane
what is the epidural (extradural) potential space?
middle meningeal arteries supply dura : rupture > haematoma
what is the subdural potential space?
bridging veins connecting to venous sinuses : rupture > haematoma
what is the subarachnoid space?
CSF, cerebral arteries/veins, arachnoid trabeculae (connective)
what is meningitis?
inflammation of the meninges, usually a viral or bacterial infection. can lead to brain damage; cerebral oedema, raised inter cranial pressure can cause herniation
what is the cerebrospinal fluid?
fills the ventricles of the brain and subarachnoid space of the meninges, usually have about 125-150ml total
what is the function of CSF?
cushions brain against impact/movement and own weight.
provides stable chemical environment for brain
nutrient and waste exchange between nervous tissue and blood
aging: reduced CSF turnover, metabolic waste build ups may contribute to neurodegenerative diseases