Please enable JavaScript.
Coggle requires JavaScript to display documents.
lecture 14 - Coggle Diagram
lecture 14
cerebro spinal fluid (CSF)
csf composition
diff betw blood N CSF
CSF has:
a lower conc. of
K+
glucose
n protein
n a higher conc. of
Na+
Cl-
CSF normally
lacks blood cells
the increased conc. of Na+ n Cl-
enables CSF to be
isotonic
to blood
-despite having a much lower conc.of proteins in CSF
(a solution having the same osmotic pressure as some other solution)
-
also look at table
the extracellular fluid within the CNS
communicates directly with the CSF
so composition of CSF
indicates- the composition of
extracellular environment of the neurons
in the brain n spinal cord
CSF circulation
CSF is formed in the
lateral ventricles
passes thru the intrerventricular foramina
(foramen of Monro)
into the
3rd ventricle
frm there it flows thru the-cerebral aqueduct
(aqueduct of sylvius)
into the
4th ventricle
some pass into
the central canal
of spinal cord
most
thru median aperture of 4th ventricle
- Foramen of Magendie
& 2 lateral apertures of 4th ventricle
- Foramina of Lushka
1 more item...
Functions of CSF
at least 5
decreases the sudden pressure
or
forces
on delicate nervous tissue.
CSF
nourishes nervous tissue.
-
Only CSF comes in contact with neurons.
-
Even blood cannot directly come in contact with neurons.
-It provides nourishment n returns products of metabolism
to the venous sinuses.
constantly provide glucose and O2 to neurons
Neurons cannot live without glucose and oxygen for more than 3–5 minutes.
Pineal gland secretions reach pituitary gland
via CSF.
cushions the brain within its solid vault
.
The brain and CSF have approximately the same specific gravity, so that the brain simply floats in the fluid.
passage of drugs to neurons
T
here is no CSF–brain barrier, so drugs can reach
the neurons through CSF.
There is blood–CSF barrier. There are no antibodies in CNS, making infections of brain very serious entity.
lumbar puncture
changess in common disorders
is a procedure by which CSF is taken out frm
the subaracnoid space
drawn by a needle betw 3rd n 4th lumbar vertebrae
study of CSF gives info about disease affecting CNS
pressure
is incresed in
subaracnoid hemorrhage
acute bacterial meningitis
& tuberculous meningitis
colour
is blood stained in
subaracnoid hemorrhage
is cloudy in
acute bacterial meningitis
& tuberculous meningitis
RBC
count is incr in
subaracnoid hemorrhage
glucose
is decr in
acute bacterial meningitis
& tuberculous meningitis
proteins
is incr in
subaracnoid hemorrhage
acute bacterial meningitis
tuberculous meningitis
viral meningitis
& mutiple sclerosis
micro organisms
are demostrated in
1 more item...
subaracnoid hemorrhage
pressure incr
color blood stained
RBC counts incr
proteins incr
2 more items...
blood brain barrier BBB
significance
- restricts movem of large molecules n highly
charged ions frm the blood into brain n SC
clinical significance
P-Glycoprotein is a multidrug nonspecific transporter present in the apical membrane of the endothelial cells. This multidrug nonspecific transporter transports a large number of drugs or peptides back into the blood which cross cerebral capillaries.
In the absence of this transporter, the concentration of various chemotherapeutic agents, analgesic and opioid peptide is higher
than in control. Therefore, the inhibitors of this transporter can be of great value for achieving proper concentration of therapeutic treatment
of CNS disorders and tumors.
hydrocephalus
causes
Obstruction to CSF circulation,
Excessive production of CSF
& Interference with absorption of CSF.
signs
Acute hydrocephalus
due to
intraventricular bleeding
may cause
stupor
& coma.
Subacute hydrocephalus
(develops over few days)
produces:
progressive drowsiness
lethargy
& incontinence.
Chronic hydrocephalus
(developing over few weeks)
causes:
movement difficulties
& incontinence.
an abnormal accumulation of CSF in the
cranium.