o Provides a physiological system to supply nutrients to the nervous tissue
o Removes metabolic wastes
o Produces a mechanical barrier
Cerebrospinal Fluid
Formation and physiology
Lines the brain and spinal cord
Meninges
Formation and physiology
___________ - Outer layer that lines the skull and vertebral canal
____________________ - Middle layer; filamentous inner membrane
___________ - Thin membrane that lines the surfaces of brain and spinal cord
Dura mater
Arachnoid mater
Pia mater
CSF is produced in the _________________
approx. ________ in Adults
Choroid plexus of the 2 lateral ventricles and the 3rd and 4th ventricles
20mL/hr
Needed CSF volume to maintain
____ - ______ in Adults
____ - ______ in Neonates
90-150 mL
10-60 mL
Capillary networks that form the CSF plasma
Choroid plexus
Mechanisms of selective filtration (2)
o Hydrostatic pressure
o Active transport secretion
True or False
CSF Chemical composition does not resemble and ultrafiltrate
________ - derived from Blood CSF Barrier
________ - derived from CSF Brain Barrier
TRUE
70%
30%
Site of Reabsorption
Arachnoid Granulations/Villae
Specimen collection and handling
Collection method: _______________ between the _________________
Factors affecting volume:
(2)
Lumbar puncture
3rd, 4th, 5th lumbar vertebrae
o Volume available in the patient
o Opening pressure of the CSF taken
Specimen collection and handling
True pr False
o In collecting, Prevent introduction of infection or damaging the neural tissue
o Up to 10mL of CSF can be collected using a manometer attach to a spinal needle
What position is assumed by the patient during CSF collection? _________________
True
False - 20mL
Lateral Decubitus/Fetal Position
Specimen collection and handling
A surgical procedure in which an opening from the outside is made to the lateral ventricle areas of the brain
Ventricular Puncture
Specimen collection and handling
Puncture of the cisterna cerebellomedullaris with a hollow needle inserted just between the occipital bone, to obtain a specimen of cerebrospinal fluid
Cisternal puncture
Specimen collection and handling
Test are performed on a ____________
Specimens can be maintained by:
Hematology: ______________
Microbiology: _______________
Chemistry and Serology: _______________
STAT basis
Refrigeration
Store at room temp
Frozen
Specimen collection and handling
What Tube numbers
o Chemical and serologic tests
o Microbiology
o Hematology
o Microbiology or Serology (to provide better exclusion of skin contamination or for additional serologic test) - stored at RT
1
2
3
4
Specimen collection and handling
Additional chemical and serologic test
Supernatant fluid (leftover after section)
Specimen collection and handling
Not discarded but frozen
Excess fluid
Specimen collection and handling
What if only 1 CSF sample was collected?
Microbiology > Hematology > Chemistry/Serology
Specimen collection and handling
What if CSF sample is turbid?
Prepare a tube with 0.5 mL of sodium citrate per 5mL of CSF in order to prevent clotting
CSF appearance
Due to presence of RBC degradation products; commonly seen in infant particularly in premature babies
Xanthochromic
CSF appearance
Xanthochromic
_________ - very slight amount of oxyhemoglobin
_________ - heavy hemolysis
_________ - conversion of oxyhemoglobin to unconjugated bilirubin
Pink
Orange
Yellow
CSF appearance
Initial Appearance: _____________
terminology used for description: (5)
Crystal clear
Crystal clear
Cloudy/turbid
Milky
Xanthochromic: pink, orange or yellow
Hemolyzed/Bloody
