cells and tissues of nervous system Flashcards
neurones
structural and functional unit
excitable cells
impulses carried as action potentials
glial cells
non-excitable supporting cells
much smaller than neurons
impulse transmission is by action potential which can travel
- in either direction across a neuron
- in one direction fro synaptic terminals to cell body
- in one direction from cell body to synaptic terminal
myelin sheath
increase conduction speed in axons
myelin sheaths are formed by
schwann cells in PNS
oligodendrocytes in CNS
satellite cells
surround neuronal cell bodies
schwann cells
myelination
astrocytes
have endfeet
surround synapses and capillaries
help in K+ buffering
oligodendrocytes
myelination
microglia
phagocytosis
scar tissue formation
ependymal cells
line ventricles
blood brain barrier
Is a protective mechanism that helps maintain a stable environment for the brain and prevents harmful amino acids & ions present in the bloodstream and blood cells from entering the brain.
lateral ventricles
c shaped cavities which lie in cerebral hemispheres
interventricular foramen
connects lateral verntricles to 3rd ventricle
3rd ventricle
within diencephalon
cerebral aqeuduct
between 3rd and 4th ventricles
4th ventricle
diamond shape
lies in hindbrain (pons and medulla infront and cerebellum at back)
meninges
dura mater
arachnoid mater
pia mater
dura mater
tough, fibrous and has dural folds
pia mater
vascularised and disp into the folds of the brain
subdural space
potential space, traversed by blood vessels penetrating into the CNS
subarachnoid space
contains CSF
CSF
fluid insuide cavity of brain and central canal of spinal cord
where is CSF
inside ventricles
between pia and arachnoid
where is CSF formed
by choroid plexus in each ventricle
where is CSF absorbed
by arachnoid villi into saggital sinus
