anatomy 4 Flashcards
(22 cards)
what is the CNS covered in
menings
menings=
layer of tissue separating CNS from the rest of the body
menings is comprised of three layers
1- piamater
2-arachnoid mater
3- dura mater
the pia mater is
adherent to the brain, dips into the sulci of the brain
arachnoid mater is
in the middle
dura mater is the
outermost, very tough layer
within menings the CNS is bathed in
Cerebro-spinal fluid (CSF)
CSF is produced by
specialised epithelium (chloroid plexus) lining cavities within the brain (ventricles)
CSF have a high conc of / and _ ions compared to plasma
sodium, chloride and magnesium
CSF circulates through…
ventricles (cavities) within the brain before exiting onto brain surface
CSF is reabsorbed into venous circulation at specialised points called
arachnoid granulation
ventricles=
spaces or cavities within the brain linked by passageways called aqueducts
ventricles allow CSF to
circulate through the brain
lumbar puncture=
CSF removed with a needle with minimal risk of nerve damage
increased levels of white blood cells indicates
infection such as meningitis
increased levels of red blood cells in CSF indicates
brain haemorrhage/stroke
in adults the spinal cord terminates at
L1
spinal nerves for levels below L1 must
leave spinal cord near its termination/descend into menings, floating in CSF until they exit at their vertebral level
in the space inferior to termination of spinal cord, the nerves within the menings=
cauda equina
increased white blood cells in CSF indicate an infection such as
meningitis
increased red blood cells in CSF indicate
brain haemorrhage/stroke
there is not enough space around the spinal cord to allow for…
safe removal of CSF superior to its termination
