CSF

Question 1

Csf definition

Answer 1

Clear, colour less, transparent fluid that circulates through ventricles of brain, sub arachnoid space, central canal of sp cord
Part of ECF

Question 2

Properties of csf
Composition - Na > k, lymphocytes also present in csf at sp cord

Answer 2

Vol - 150ml ,Sp. gra - 1.005
Rate of formation - 0.3ml/min
Reaction - alkaline
Composition : water, 0.87%solids
Solids - organic, inorganic
#Organic - AA proteins, cholesterol, urea , uric acid, creatinine, lactic acid
# Inorganic -Na, k, ca, mg, cl, ph, bicarb

Question 3

Circulation of csf
1) Formation of caf in lateral ventricle
2) through foramen of Monro
3) goes to thrid ventricle
4) through aqueduct of sylvius goes to fourth ventricle

Answer 3

5) pass through foramen of Magendie, foramen of Luschka
6) went to cisterna MAGNA, lateralis
7) goes to sub arachnoid space
8) then to sp cord, cerebral hemispheres

Question 4

Site of formation
Mechanism of formation
Mechanism of absorption,
site of absorption

Answer 4

1) formed by choroid plexus within the ventricles,these are tufts of capillaries
2) formed by a secretion mechanism involving active transport,
Doesn’t involve ultra filtration
3) filtration is absorption mechanism
4) absorbed mostly at arachnoid villi

Question 5

Csf functions

Answer 5

1) protective - acts as fluid buffer & prevent brain from shock, brain float
Act as cushion when blow occur
2) cranial content regulation
Brain is effected if cranial content ⬆️ in cerebral hemorrhage, tumors
Prevented by ⬆️absorption of csf
3) medium of exchange
Nutrition,waste materials exchanged

Question 6

Hydrocephalus - abnormal accumulation of csf cause head enlargement
Types : internal, external

Answer 6

Internal / non communicating - accumulated in ventricles by aqueduct blockage cause dilation of ventricles
External / communicating - accumulation of csf in sub arachnoid space,dilation of ventricles,cause head enlargement, arachnoid villi blockage

Question 7

Congenital hydrocephalus - birth defect with accumulation of csf
Causes, features

Answer 7

Causes - obstruction of aqueduct due to blockage, tumor, cysts,hemorrhage
Features - large sized head compared to rest of the body, irritability, seizures, vomiting etc

Question 8

Lumbar puncture - needle introduced into sub arachnoid space in lumbar region b/w L3-L4

Answer 8

Posture - person bent forward, to flex vertebrae, body brought to edge table
- highest point of iliac crest is determined, a line is drawn on back by joining iliac crest , in midline L4 seen
- after determination of L4, L3 is palpated, needle is given b/w them

Question 9

Reason for selecting that site of lumbar puncture
Uses of it 3

Answer 9

1) sp cord is not injured, it terminates at lower border of L1 but cauda equina is damaged but regenerated
2) sub arachnoid space is wider at this site, because piamater is reduced
Uses : for diagnosis, for injecting spiral anesthesia, for measuring pressure